adult female baboons were studied for at least one menstrual cycle for patterns of urinary estrogens , plasma , progestin , and in some cases urinary lh . only those animals displaying normal patterns of these hormones were immunized . the criteria for normality and the procedures for housing animals are well known and will not be described . human luteinizing hormone ( hlh )-- partially purified preparation from human pituitaries with a biological potency of 2 . 5 units per mg . ( nih - lh - si ). human follicle stimulating hormone ( hfsh )-- a partially purified preparation from humand pituitaries with a biological potency of 86 units per mg . ( nih - fsh - si ). human chorionic gonadotropin ( hcg )-- a highly purified preparation from human pregnancy urine with biological potency of 13 , 200 iu / mg . ( 2nd irp - hcg ). monkey luteinizing hormone ( mlh )-- a crude preparation from rhesus monkey pituitaries with a biological potency of 0 . 75 units per mg . ( nih - lh - si ). baboon luteinizing hormone ( blh )-- partially purified baboon pituitary preparation with a biological potency of 1 . 1 units per mg . ( nih - lh - s1 ). all preparations , excepting the olh , were prepared in the inventor &# 39 ; s laboratory . lh and hcg biological activity was determined by the ovarian ascorbic acid depletion test and the fsh preparation assayed by the ovarian augmentation assay . hormones were altered as antigens by coupling with a hapten in varying ratios of hapten to hormone as described by cinader et al ., supra . for convenience , the cinader process is discussed herein although phillips , supra , may provide a more stable bond under certain circumstances . in this procedure , the protein hormone serves as a carrier and the hapten is coupled to it by diazo bonds . although a variety of hapten groups were coupled to different hormones , the same basic procedure was used for any combination . fifteen to thirty - five haptenic groups per hormone molecule were found most useful for preparing immuizing antigens . the basic reaction consisted of diazotizing the hapten ( sulfanilic acid ) by adding it to a solution of 0 . 11 n hcl and then slowly adding this solution dropwise to a 1 percent solution of nano 2 with constant stirring at 4 ° c . diazotization was considered complete with free hno 2 was detected in the reaction mixture . although the above reaction was accomplished at 4 ° c ., optimum temperatures for the reaction normally are about 0 °- 6 ° c ., although 4 ° c . is preferred . the hapten - protein coupling was performed by dissolving the protein hormone in an alkaline buffer , ph 8 . 0 . the diazotized hapten was added slowly to the hormone solution with continuous stirring at 4 ° c . the ph of the reaction was constantly monitored and kept near 8 . 0 . after all the hapten was added , the ph was finally adjusted to 8 . 0 , stirred for 1 - 2 hours and allowed to stand at 4 ° overnight . the mixture was thoroughly dialyzed for 6 - 8 days against distilled water to remove unreacted hapten . although the number of diazo groups per hormone molecule could be regulated by the number of moles of hapten and hormone reacted , a parallel control experiment with s 35 labelled sulfanilic acid to evaluate the precise composition of the haptenprotein samples was performed with each diazotization . the same hormone preparation to be used for immunization was used in the control experiment . after the reaction was completed , an aliquot was taken from the reaction mixture and the remainder thoroughly dialyzed . equal volumes of the dialyzed and undialyzed solutions were counted by liquid scintillation . by comparing the counts of the dialyzed and undialyzed samples , the moles of hapten coupled to each mole of hormone was calculated since the unreacted hapten was removed by dialysis . for this calculation , a molecular weight of 30 , 000 was assumed for all gonadotropin preparations . following dialysis , hapten - hormones were lyophilized and stored at 4 ° c . diazo - hcg ( 35 groups / molecule ) and hlh ( 26 groups / molecule ) were bioassayed by the ovarian ascorbic acid depletion method and found to retain 62 and 85 percent respectively of the activity of the unaltered hormones from which they were derived . none of the other hormones were assayed for biological activity . female baboons received their initial immunization on days 3 - 5 of the menstrual cycle and the second and third injections one week apart . the fourth injection was given 2 - 3 weeks after the third . a few animals received a fifth injection at 70 - 80 days after the first injections . all antigens were administered subcutaneously in a suspension of mannide manoleate or peanut oil . doses of antigens for each injection varied between 3 and 5 mg . injection sites were inspected daily for 5 days after each immunization for local reactions . daily 24 - hour urine specimens and frequent serum samples were collected during at least one menstrual cycle prior to immunizations and following immunizations until the effects of treatment were assessed . urinary lh , urinary estrogens and plasma progestins were measured . antibodies were detected in post - immunization serum samples by reacting 0 . 2 ml . of a 1 : 1000 dilution of serum in phosphate - buffered saline ( ph 7 . 4 ) 0 . 5 percent normal baboon serum with 250 pg of 1 131 labelled hormone . sera were reacted with both the unaltered immunizing hormone and unaltered baboon lh for antibody detection . a purified baboon lh preparation ( 1 . 9 × nih - lh - s1 ) was used as a tracer antigen . antigen - antibody complexes were precipitated with ovine anti - baboon gamma globulin after a 24 - hr . incubation at 4 ° c . antibody levels were expressed as pg of labelled hormone bound . significant antibody levels were considered to be those that would bind 5 . 0 pg or more of the 1 131 labelled antigen . antisera were fractionated by gel filtration of sephadex g - 200 according to the procedure of fahey and terry ( at p . 36 , experimental immunology , f . a . davis co ., philadelphia , pa ., 1967 , incorporated by reference to the extent necessary to understand the invention ) to determine the proportion of igm and igg antibodies in the baboon sera . since the igg fraction in this procedure contained a portion of iga and igd antibodies , only igm and total titers were determined . the igm fraction from the column was reacted with 1 131 hormones and the binding capacity determined . the volumes of the fractionated sera were adjusted so that antibody levels would be comparable to those of whole serum . no significant reactions were observed at the site of injection following any immunization . on 4 occasions , a slight induration ( 2 - 3 cm in diameter ) was seen when mannide manoleate was used as a vehicle but the redness and swelling disappeared within 4 - 5 days . antibodies were detected against the immunizing antigen within 3 - 5 weeks in all animals . the extent , duration and cross reactivity of these antibodies is recorded . generally speaking , higher levels were observed to heterologous gonadotropin immunization than to homologous ones . the cross - reactivity of induced antibodies with baboon lh was studied on each animal . cross - reactivity of antisera at peak levels was recorded . although relatively high antibody activity against human lh and hcg were seen , relatively little reaction with baboon lh occurred . an intermediate cross - reaction was noted with anti - ovine lh and a high degree of cross - reactivity was seen with anti - monkey lh . diazo - human fsh was weakly antigenic in the baboon . the duration of antibody production was generally longer with the human and sheep gonadotropin immunization than with those of monkey or baboon origin . peak antibody levels usually occurred at the time when the antibodies had shifted to principally the igg type . early antibodies had a larger proportion of igm type and were generally more cross - reactive with baboon lh . the change in the proportion of the total antibody population that was igm was recorded from the time antibodies were first detected . significant cross - reactivity to baboon lh was observed in anti - human gonadotropins when igm was abundant but dropped sharply as the antisera shifted to nearly all igg . this drop in cross - reactivity did not occur with monkey and baboon immunizations . again , the ovine lh immunizations produced an intermediate change in reactivity with the shift from igm to igg . the effects of immunization upon the event of the menstrual cycle were determined by observing changes in sex skin turgescence and levels of pituitary and / or ovarian hormones . based on these parameters , the delay or retardation of ovulation from the expected time , as judged by the control cycle , was calculated . one animal immunized with hcg had no interruption in ovulation and another immunized with hfsh was delayed for only one cycle . two animals injected with hlh and two injected with hcg had ovulation delays equivalent to two menstrual cycles . a third animal immunized with hlh was delayed a calculated 86 days . ovine lh immunizations produced an 88 day delay in ovulation . immunizations with diazo - monkey or baboon lh resulted in longer disruption of the menstrual cycle . calculated delays in ovulation for the two animals receiving monkey lh was 146 and 122 days whereas the animals receiving altered baboon lh were retarded from ovulation 224 and 210 days . effects on specific hormone patterns following immunization with hlh in one animal were recorded . the interval between menses was considered to represent a &# 34 ; cycle &# 34 ;. urinary estrogens and plasma progestin patterns indicated that no ovulation occurred during the cycle of immunization which was 85 days in duration . urinary estrogens were elevated during treatment but did not reflect a typical pattern . plasma progestins were not elevated until about day 19 of the final post - treatment cycle . patterns of both estrogens and progestins were within normal limits during the second post - treatment cycle . antibody levels were elevated from about day 35 of the treatment cycle until 289 days from the first detection of antibodies . an lh assay was not available when this animal was studied and no data on plasma or urinary levels of this hormone was obtained . hormonal patterns following an immunization with diazobaboon lh were recorded . in this animal , antibody levels were lower and persisted , in general , for a shorter period than did immunizations with human gonadotropins . during the treatment cycle , levels of urinary estrogens and plasma progestins followed a normal pattern but were quantitatively lower than normal . urinary lh patterns fluctuated markedly due to the injections of diazo - lh during this period . no conclusive evidence of ovulation was obtained for the treatment cycle . the first post - treatment cycle lasted 246 days . during this cycle urinary lh and estrogens were elevated on days 35 - 41 but there was no subsequent elevation in plasma progestins that would indicate ovulation had occurred . following day 42 of this cycle , there was no significant elevation in any of the three hormone levels until day 231 when significant elevations of urinary estrogens and lh occurred . these rises were followed 3 days later by an elevation in plasma progestins indicating the presence of a functioning corpus luteum . a second post - treatment menstrual cycle was of normal duration and the endocrine patterns were normal . antibodies to unaltered baboon lh attained maximum levels by about day 70 of the post - treatment cycle and remained relatively constant until day 190 when a steady decline was observed . by day 215 of this cycle , antibody levels were barely detectable . approximately 16 days after this time , a peak of lh commensurate with a normal midcycle elevation was observed . from this point the animal appeared to have the normal function of the pituitaryovarian axis . hormonal patterns in animals with other heterologous gonadotropin immunizations were similar to animal receiving hlh and other animals receiving monkey or baboon lh were similar in response to animal receiving baboon lh . these results in baboons indicated that the modification of a reproductive hormone , by the procedures outlined , did render it antigenic and the antibodies thus formed did neutralize natural endogenous hormones if the natural hormone was obtained from the species receiving the immunizations with modified hormone . hcg is a hormone naturally present only in pregnant women with the exception that an entity at least analogous thereto has been found to be present in humans in conjunction with neoplasms . hcg is also commercially available . human lh is immunologically and biologically identical to hcg , even though there are chemical differences . since they are biologically identical and hcg is readily available from commercial sources it was presumed that the effectiveness of this immunological procedure could be evaluated by injecting modified hcg into non - pregnant women and monitoring the blood levels of lh . antibodies formed will neutralize both the lh and the modified hcg . reference in the above regard is made to the publications identified earlier herein . women have a pattern of lh levels ; the level is substantially constant until the middle period between menstrual cycles , immediately prior to ovulation ; at that point the lh level rises greatly and helps induce the ovulation . monitoring the lh level and the antibody level will show that the procedure used did or did not cause the production of antibodies capable of neutralizing the endogenous reproductive hormone , namely lh . a women aged 27 years was selected for study . hormone was obtained , purified and modified . the modified human hormone ( hcg ) was injected into the subject . it is well known that antibodies to hcg react identically to lh as well as hcg . the effect of the immunization was evaluated , principally by monitoring blood levels of lh . finally the results were evaluated . clinical grade hcg derived from pregnancy urine was obtained from the vitamerican corp . little falls , n . j . this material has an immunological potency of 2600 iu / mg . contaminants were detected in this preparation . purification consisted of chromatography and elution . fractions were dialyzed and lyophylized . the most potent fraction contained approximately 7600 iu / mg ., however , it was heterogenous on polyacrylamide gel electrophoresis . the fraction was further purified by gel filtration . the elution profile revealed two major protein peaks . the most potent hcg was found in the first peak and had an immunological potency of 13 , 670 iu per mg . this fraction was subjected to polyacrylamide gel electrophoresis . further purification by gel filtration showed no evidence of heterogeneity of the hcg at this stage . consequently , materials for study were processed according to the above procedure . the contamination of this purified hcg was tested with i 131 used for identification and a sample was reacted with antisera against several proteins offering potential contamination . those proteins were follicle stimulating hormone , human growth hormone , whole human serum , human albumin , transferin , alpha one globulin , alpha two globulin and orosomucoid . no detectable binding of the purified hcg was observed with any antisera at a dulution of 1 : 50 of each . these negative results , calculated against potential binding of the respective proteins , indicated that contamination with any was less than 0 . 005 percent . hormone was altered by coupling with a hapten ( sulfanilazo ). this method couples the hapten molecules to the protein via the amino group of the aliphatic or aromatic portion of the hapten . the number of hapten molecules coupled to each hcg molecule ( ha - hcg ) can be regulated and for this study , forty haptenic groups per hcg molecule were used for preparing the immunizing antigen . the subject was multiparous and had terminated her reproductive capabilities by prior elective bilateral salpingectomy . she was in good health and had regular cyclic menstruation . she underwent complete history , physical examination and laboratory evaluation including blood count , urinalysis , latex fixation and papanicolau smear . she had no history of allergy . to demonstrate normal functioning of the pituitaryovarian axis prior to immunization , blood samples were obtained every other day from the first day of menses for 10 days , then daily for 10 days and finally , every other day until the next menses . serum determinations of fsh , lh , estrone , estradiol and progesterone were performed . these studies indicated an ovulatory pattern . ten mg . of the ha - hcg antigen were dissolved in 1 . 0 ml . of saline and emulsified with an equal volume of oil . prior to injection , scratch tests to antigen and vehicle were performed . immunizations were begun in the luteal phase of the treatment cycle to prevent superovulation from the administered hcg . four injections at two week intervals were given to the subject . the first two of these were administered in oil subcutaneously ( 1 . 0 ml . in each upper arm ); the final two injections were given in saline only via the intradermal route . following each injection , blood pressure readings were taken and the subject observed for allergic reactions . blood samples were collected at weekly intervals beginning two weeks after the initial injection to test for the presence of humoral and cellular antibodies . following completion of the immunization schedule , blood samples were collected in the same manner as in the control cycle to assess effects of immunization on hormonal patterns of the menstrual cycle . since antibodies to hcg react identically to lh as with hcg , lh was monitored as an index of effectiveness of the procedure . a third cycle was similarly studied six months after initial immunization . upon completion of the study , physical and pelvic examinations and laboratory evaluations were repeated . serum samples from the control and post - treatment cycles were assayed for fsh , lh , estrone , estradiol and progesterone . the subject was tested for delayed hypertensivity before immunization and at two week intervals until the injection schedule was completed by an in vitro lymphocyte transformation test . temporal relationships of serum pituitary and gonadal hormones in the control cycles of the subject were recorded . antibody titers to hcg were detected in the subject after two injections . menses occurred at regular intervals during the immunizations . following the initial injection in mannide manoleate , some itching and swelling at the injection site occurred . subsequent intradermal injections in saline produced no reactions and it was concluded that the local reactions were induced by the mannide manoleate . lymphocyte transformation tests on plasma samples were negative . in the post - treatment cycle , baseline follicular and luteal phase lh levels were not noticeably changed in the subject . very small midcycle elevations in lh levels were observed as compared to the normal large increases . fsh patterns in the post - treatment cycle were normal . this indicated that the antibodies were neutralizing the action of endogenous lh . the subject showed an ovulatory progesterone pattern but attained relatively high antibody titers to lh and hcg after only two injections of ha - hcg . the subject was studied during another cycle approximately six months from the first immunization . significant antibody titers were found . lh patterns indicated a small midcycle elevation . fsh patterns were essentially normal . thus , the specificity of anti - hcg antibodies to lh was shown but not to fsh . another woman aged 29 years was selected for further study . hormone was obtained , purified , and modified as in example ii . this modified hormone was injected into this subject in the same way as in example ii . the subject was monitored and tested as in example ii . the results were similar to the results found in example ii except that ( 1 ) the levels of estrone and estradiol were substantially normal , ( 2 ) the subject acquired significant antibody titers late in the post - immunization cycle , and ( 3 ) in the cycle studied after six months this subject showed no significant midcycle elevation in lh patterns . anther woman aged 29 years was selected for further study . hormone was obtained and purified and modified as in example ii . this modified hormone was injected into this subject in the same way as in example ii . the subject was monitored and tested as in example ii . the results were similar to the results found in example ii except that ( 1 ) baseline follicular and luteal phase lh levels were noticeably depressed in the post - treatment cycle , ( 2 ) no midcycle elevations were observed in lh , ( 3 ) estrone levels were elevated during the follicular phase of the post - immunization cycle , and ( 4 ) during the six - months study there was no significant midcycle elevation in lh patterns . another woman aged 35 years was selected for further study . hormone was obtained , purified , and modified as in example ii . this modified hormone was injected into this subject in the same way as in example ii . the subject was monitored and tested as in example ii . the results were similar to the results found in example ii except that ( 1 ) baseline follicular and luteal phase lh levels were noticeably depressed in the post - treatment cycle , ( 2 ) a very small midcycle elevation of lh were observed , ( 3 ) levels of fsh patterns in the post - treatment cycle were depressed , and ( 4 ) levels of both estrone and estradiol were reduced , during the follicular phase of the post - immunization . another woman aged 28 years was selected for further study . hormone was obtained , purified , and modified as in example ii . this modified hormone was injected into this subject in the same way as in example ii . the subject was monitored and tested as in example ii . the results were similar to results found in example ii except that ( 1 ) baseline follicular and luteal phase lh levels were depressed in the post - treatment cycle , ( 2 ) no peaks were observed in midcycle levels of lh , ( 3 ) estrone levels appeared elevated in the follicular phase of the post immunization cycle , and ( 4 ) lh patterns indicated no significant midcycle elevation in the six - month post - immunization cycle . another woman aged 28 was selected for further study . hormone was obtained , purified , and modified as in example ii . this modified hormone was injected into this subject in the same way as in example ii . the subject was monitored and tested as in example ii . the results were similar to results found in example ii except that ( 1 ) antibody titers to hcg were not detected until after three injections , ( 2 ) baseline follicular and luteal phase lh levels were depressed in the post - treatment cycle , ( 3 ) no peaks nor midcycle elevation in the lh were observed , ( 4 ) estrone levels were elevated during the follicular phase , and ( 5 ) no significant antibody titers were found in the six - month cycle . all the above examples show the practicality of injecting modified hormones for the purpose of neutralizing an endogenous reproductive hormone and thereby offering a procedure for the prevention of conception or the disruption of gestation . data obtained in earlier experiments and discussed in examples i - vii showed that a modified natural reproductive hormone , when injected into an animal of species from which it was derived , would produce antibodies that would neutralize the action of the unmodified endogenous natural hormone in the body of the animal . hormones used in examples i - vii were fsh , lh and hcg . new experiments were performed , baed on this knowledge , to identify another reproductive hormone ( placental lactogen ) that could be used in a similar fashion . a purified preparation of placental lactogen was prepared from placentae of baboons since it was intended to use modified placental lactogen to immunize baboons . placentae were extracted and purified on column chromatograph according to previously published procedures . the purity was tested by polyacrylamide gel , electrophoresis and by radioimmunoassay . the material obtained showed a high degree of purity on electrophoresis and radioimmunoassay showed no contamination with other placental hormones . the baboon placental lactogen ( bpl ) was altered by coupling with the diazonium salt of sulfanilic acid as outlined for other hormones in example i . the number of diazo molecules per bpl molecule in this instance was 15 . immunization procedures were also similar to those described in example i for other hormones . within 4 - 6 weeks after the first injection of diazo - bpl , antibody levels to natural unmodified bpl in vitro were detected in 6 female baboons . levels rose to a plateau within 8 - 10 weeks and remained there for several months . hormonal measurements indicated that there were no efects on the normal events of the menstrual cycle due to the immunizations . since bpl is normally secreted only in pregnancy , this was not a surprising observation . all six females were mated with a male of proven fertility three times ( once each in three different cycles during the fertile period ). pregnancy diagnosis by hormonal measurement was performed after each mating . from the 18 matings , there were 13 conceptions as judged by pregnancy tests . the animals that were pregnant had menstrual bleeding 7 - 12 days later than was expected for their normal menstrual cycles . subsequent hormonal measurements confirmed that these 13 pregnancies were terminated by abortions approximately one week after the time of expected menses . these findings suggest that the antibodies formed in the animal &# 39 ; s body after immunization had no effect on the nonpregnant menstrual cycle but when pregnancy was established , they neutralized the baboon placental lactogen in the baboon placenta and the result was abortion very early after conception . when in examples i - viii above structures ( i ), ( ii ), and ( iii ) are modified by use of diazosulfanilic acid , dinitrophenol , or s - aceto mercaptosuccinic anhydride or structures ( ii ), and ( iii ) are modified by addition of polytyrosine or polyalanine , according to known methods , the results obtained should be similar to those in said examples . similarly , when fsh , somatomedian , growth hormone or angiotension ii are modified by use of diazosulfanilic acid or trinitrophenol , the results obtainable upon administration of the purified modified polypeptide into a male or female human or animal would indicate the stimulation of antibodies which neutralize all or some of the modified polypeptide as well as corresponding endogenous polypeptide . the subjects used in the studies reported in the example are female baboons . all baboons were adults of reproductive age . a description of subjects and the conditions of experimentation have been described in example i . the animals have been studied using highly purified beta subunits of hcg using a preparation with a biological activity of less than 1 . 0 iu / mg . animals were immunized with 14 - 26 moles / mole of polypeptide of diazosulfanilic acid coupled subunits in mannide manoleate . antibody levels were assessed by determining the binding of serum dilutions with i 125 labelled antigens . crossreactivity of antisera was measured by direct binding of labelled antigens and by displacement radioimmunoassays . antifertility effects in actively immunized animals were tested by mating females with males of proven fertility . effects in pregnant baboons passively immunized with either sheep or baboon anti - β - hcg were determined by monitoring serum levels of gonadotropins and sex steroid hormones before and after immunizations . eight female baboons were immunized with the modified beta subunit of hcg . significant antibody levels were attained in all animals . baboon immunizations with the modified beta subunit of hcg resulted in high antibody levels reacting to hcg , human lh and baboon cg but not to baboon lh . all animals remained ovulatory , however , no pregnancies resulted from numerous matings with males of proven fertility . passive immunization of non - immunized pregnant baboons with sheep anti - β - hcg serum produced abortions within 36 - 44 hours . hemocyanin from keyhole limpet ( klh ) solution ( 7 mg / ml ) in 0 . 05 m sodium phosphate buffer in 0 . 2 m nacl , ph 7 . 5 , is prepared . insoluble particles are removed by centrifugation . to one ml of this solution , tolylene diisocyanate ( t . d . i . c .) reagent is added ( 20 μl ) diluted to 1 / 30 with dioxane , the amount being essentially the equivalent of the moles of lysyl residues in the klh molecules . after 40 minutes at 0 ° c ., the t . d . i . c . activated klh solution is combined with 0 . 5 mg of synthetic β - hcg peptide having the following structure : which is first dissolved in 25 μl of 0 . 05 m sodium phosphate buffer in 0 . 2 m nacl , ph 7 . 5 . the mixture is incubated at 37 ° c . for four hours . the resulting product is purified by gel filtration . one g . of ficoll 70 is dissolved in 1 ml each of normal saline and 2 m ethylene diamine ( adjusted to ph 10 with hydrochloric acid ) solution . the solution is kept at room temperature in a water bath and stirred with a magnetic stirrer . cyanoger bromide , 4 g , dissolved in 8 ml of dioxane , is added to the picoll 70 solution . the acidity of the mixture is maintained at ph 10 - 10 . 5 for 8 minutes by adding drops of 2 n sodium hydroxide solution . an additional 2 ml of 2 m ethylene diamine , ph 10 , solution is added , and stirring at room temperature is continued for 30 more minutes . the product is purified by passing it through a bio - gel p - 60 column . two mg of the compound of structure ( ii ) containing picogram amount of i 125 labeled adduct and klh ( 1 . 6 mg ) is dissolved in 1 ml . of 1 . 0 m glycine methyl ester in 5 m guanidine hydrochloride . ethyl dimethylamino propylcarbodiimide ( e . d . c .) 19 . 1 mg is added to this solution . the acidity is adjusted to and maintained at ph 4 . 75 with 1 n hcl at room temperature for 5 hours . the klh - peptide conjugate is purified by passing it through a bio - gel p - 60 2 . 2 × 28 cm column equilibrated with 0 . 2 m nacl . solid bifunctional imidoester dihydrochloride ( 3 mole ) is added in 2 mg portions at 5 - minute intervals to a constantly stirred solution of 1 mole of polypeptide of structure ( ii ) ( 1 - 20 mg / ml ) in 0 . 1 m sodium phosphate , ph 10 . 5 , at room temperature . sodium hydroxide 0 . 1 n is added to maintain the acidity at ph 10 . 5 . one hour after the addition of the diimidoester has been completed , a polymerized product according to this invention is obtained . to a 20 mg / ml solution of homologous serum albumin in 0 . 1 m borate buffer , ph 8 . 5 , 1000 % mole excess of 25 % aqueous solution of glutaric dialdehyde is added at room temperature . the excess dialdehyde is removed by gel filtration in water using bio - gel p - 2 . the material collected at the void volume is lyophilized , and the dried product is redissolved in 0 . 1 m borate buffer , ph 8 . 5 ( 20 mg / ml ), mixed with the required amount of polypeptide of the following structure : structure ( xvi ) ( 20 mg / ml ) in the same buffer at room temperature . twenty minutes later , sodium borohydride in 250 percent molar excess of polypeptide xvi is added . the reaction is terminated after one hour . the conjugated product is purified by gel filtration on bio - gel p - 60 column , dialyzed free of salt and lyophilized . ficoll 70 l g , nahco 3 500 mg , cyanuric chloride 3 g , h 2 o 20 ml , and dimethylformamide 80 ml ., are stirred at temperature below 16 ° c . for 2 hours . the product is dialyzed against distilled water until cl - free , then lyophilized . a polypeptide of structure ( xv ) ( 2 mg ) containing minute quantity of i 125 - labeled analogue is incubated with 1 mg of this product in 0 . 25 ml of 0 . 2 m sodium borate buffer , ph 9 . 5 , for one hour at 20 ° c ., and the product is recovered from a bio - gel p - 60 2 . 2 × 28 cm column . when the above procedure is carried out and dextran t 70 is used in place of ficoll 70 , the corresponding modified polypeptide , useful according to this disclosure , is obtained . ficoll 70 l g , naio 4 1 . 2 g , and kcl 0 . 42 g are dissolved in 1 . 5 ml of 1 m sodium acetate buffer , ph 4 . 5 , and incubated at 37 ° c . for 1 hour . two mg (= 588 μmoles ) of polypeptide of structure ( xv ) above mixed with a minute quantity of i 125 - labeled analogue is incubated with 2 mg of the product obtained above in 0 . 3 ml of 0 . 2 m borate buffer , ph 9 . 5 at 55 ° c . for 1 hour . the reaction mixture is then chilled in an ice water bath and nabh 4 1 mg is then added into this solution . the reduction reaction is terminated by passing the product through a bio - gel p - 60 2 . 2 × 28 cm column equilibrated and eluted with 0 . 2 m nacl . numerous rabbits are immunized with a variety of synthetic peptides conjugated to different modifying groups . following two or three immunizations at 3 - 5 week intervals , sera from animals are assessed by determining their ability to bind in vitro to radiolabeled hcg . the specificity of this binding is studied by reacting the same sera against similarly labeled other protein hormones , particularly , pituitary lh . sera are further assessed by determining their ability to inhibit the biological action of exogenously administered hcg in bioassay animals . thus , the increase in uterine weight of the immature female rat in resonse to a prescribed dose of hcg is noted . the dose of hcg is administered subcutaneously in saline in five injections over a three day period and the animal is sacrificed for removal of the uterus on the fourth day . the weight of the uterus increases in dose reponse fashion to the hormone injections . when assessing the effects of antisera in this response , varying quantities of test serum are administered intraperitoneally separately from the subcutaneous injection of hormone during the assay . this procedure permits the antiserum to be absorbed rapidly into the rat &# 39 ; s bloodstream and will permit interaction of it with hormone when the latter likewise enters this fluid . if the antiserum is capable of reacting with the hormone in a manner preventing stimulation of the uterus , the antiserum is considered to be effective for biological inhibition of hormone action . the frequency of animals showing a positive response to immunological binding and neutralization of biological activity is presented in iodosobenzoic acid dissolved in a slight excess of 1 n potassium hydroxide in 10 % molar excess is added to the peptide of structure ( ii ) in phosphate buffer with normal saline at ph of 7 . 0 . after thirty minutes at room temerature , the product polypeptide dimer is purified by gel filtration . to an ice water bath cooled and vigorously stirred 0 . 23 ml . of bovine gamma globulin ( 10 mg / ml ) in 0 . 05 m phosphate buffer with normal saline ( pbs ) ph 7 . 5 , 50 μl of 1 / 10 t . d . i . c . in dioxane is added . after 40 minutes , in excess t . d . i . c . is removed by centrifugation ( 0 ° c ., 10 minutes , 10 , 000 g ) and the precipitate is washed twice with 0 . 1 ml . of pbs . the combined supernatents are added to 7 . 7 mg . of the peptide of structure ( ii ) dissolved in 0 . 8 ml . of pbs , ph 7 . 5 . the mixture is stirred at room temperature for 10 minutes , then incubated at 37 ° c . for 4 hours . the conjugate product is purified by dialysis . bsa ( 10 mg / ml ) in pbs solution ( 0 . 25 ml .) is treated with 50 μl of 1 / 10 t . d . i . c . dioxane solution and conjugated to 7 . 5 mg . of synthetic β - hcg peptide of structure ( iii ) in 0 . 8 ml . of pbs ( ph 7 . 5 ) as in example xix to obtain the product . to an ice water bath cooled and vigorously stirred 0 . 6 ml . of β - hcg peptide of structure ( iii ) ( 10 mg / ml ) in phosphate buffered saline , ph 7 . 5 , is added 30 μl of 1 / 10 t . d . i . c . after 40 minutes , the excess t . d . i . c . is removed by centrifugation ( 10 , 000 g , 0 ° c ., 10 minutes ) and the precipitate is washed twice with 0 . 1 ml . pbs . the combined supernatents are added to 3 mg . of poly ( d , l - lys - als ) dissolved in 0 . 3 ml . of pbs . the mixture is incubated at 37 ° c . for 4 hours . the product is then dialyzed and lyophilized . the results set out in table i provide further evidence of the broad applicability of this invention as indicated previously in this specification . using standard methods of testing in rabbits , both immunological binding response and neutralization of biological activity were established for the medified polypeptides indicated with the result as set out in table i . antigen was prepared by reacting a diisocyanate ( t . d . i . c .-- see above ) coupling reagent with carrier ( tetanus toxoid ), extracting excess reagent and incubating activated carrier with peptide structure ( ii ). baboons were immunized with the antigen and the results of mating 4 animals three times are shown in fig1 . the figure shows that from 12 exposures ( matings ) one pregnancy resulted even though relatively low levels of immunity from the antigen were achieved . non - immunized baboons of the same colony had a fertility rate of approximately 85 %. referring to fig2 baboons were immunized initially with a beta subunit of hcg modified by diazotization in a manner similar to that described in conjunction with example ii . following this initial administration , the baboons were injected 21 and 42 days later with structure ( ii ) above having been modified by the same diazotization process . fig2 shows plots representing the levels of antibodies generated in consequence of these administrations . such quantities of antibodies are expressed as micrograms of isotopically - labeled hcg that will bind each milliliter of serum from the baboons at specified days after the initial injection . the levels shown were maintained for a period of over one year . table 1__________________________________________________________________________frequency of positive antibody responses to various hcgpeptide - conjugates number of rabbits immunological neutralization ofpeptide carrier immunized binding responses biological activity__________________________________________________________________________35 amino acid111 - 145 bovine gamma globulin 10 10 6morgan et al keyhole limpetpeptide ii hemocyanin 10 5 * 31 amino acid115 - 145 poly - d - l - alanine 10 9 5morgan et al bovine serum albumin 12 12 6peptide iii44 amino acid105 - 148 keyhole limpet hemocyanin 10 8 * peptide xvnatural109 - 145 keyhole limpetkeutman hemocyanin 10 10 * peptide xii__________________________________________________________________________ * additional time needed for assessment referring to table 2 , the results of breeding the two baboons represented in fig2 is revealed in tabular form . the table presents the results of mating these animals ten times over a period of approximately one year . these data suggest that the animals ovulated in every cycle , however , no pregnancy was observed , as indicated by the animal having a menstrual period at or before the expected time therefor . while the results tabulated demonstrate the efficacy of the entire procedure , it was observed for the particular structure utilized in the primary immunization , i . e . structure ( i ), antibody cross reactivity with lh was observed . such cross reactivity may be avoided by the utilization of the fragment conjugation procedures set forth in detail hereinabove . the specificity of antibody response to a cg fragmentmacromolecular carrier is represented by the instant experiment . a 35 amino acid sequence [ structure ( ii ), herein &# 34 ; synthetic peptide &# 34 ;] of the hcg beta subunit was conjugated with bovine gamma - globulin and administered to a baboon . varying doses of each of these three hormones were tested for their ability to compete with i 125 - labeled synthetic peptide [ structure ( ii )] bound to the antiserum . the results are set forth in fig3 . note from the figure that human lh was ineffective for displacement of tracer antigen at doses up to 2 . 5 iu ( international units ). since hcg displaced antigen at a dose of 20 miu , the cross - reactivity with hlh in this assay system was less than 0 . 8 %. baboon cg also displaced i 125 - labeled antigen in this assay and , based on biological potency of the two hormones , was about 20 % as effective as hcg . the following experiments were carried out to determine whether the carbohydrate chains contained in the c - terminal 37 residues of β - hcg influence the immunogenicity of that peptide . table 2______________________________________breeding of immunized baboons [ diazo - β - hcg presensitized ] booster : diazo - β - hcg -( 111 - 145 ) 1 2pre - mate pre - matetiter ovul . preg . titer ovul . preg . ______________________________________mating no . 15 . 00 + - 4 . 20 + - mating no . 24 . 25 + - 4 . 10 + - mating no . 34 . 22 + - 4 . 00 + - mating no . 44 . 17 + - 3 . 89 + - mating no . 53 . 80 + - 3 . 76 + - mating no . 66 . 65 + - 5 . 00 + - mating no . 75 . 90 + - 4 . 75 + - mating no . 85 . 10 + - 4 . 20 + - mating no . 95 . 00 + - 4 . 25 + - mating no . 104 . 66 + - 4 . 00 + - ______________________________________ a peptide representing amino acid residues 109 - 145 of β - hcg was isolated from a chymotryptic digest of reduced and carboxymethylated β - hcg by procedures reported by keutmann , h . t . ; williams , r . m ., j . biol . chem . 252 , 5393 - 5397 ( 1977 ). this peptide is identified in table 3 as p - 1 . the purity of the peptide was confirmed by amino acid and terminal end group analyses . a portion of the isolated peptide was treated with anhydrous hydrofluoric acid ( hf ) to remove carbohydrate moieties and repurified by column chromatography according to methods described by sakakibara s . et al , bull . chem . soc . japan , 40 , 2164 - 2167 ( 1967 ). this portion of the isolated peptide is identified in table 3 as p - 2 . complete removal of the sugar chains were confirmed by carbohydrate analysis ; see nelson , norton , j . biol . chem . 153 , 375 - 380 ( 1944 ). a third peptide with the amino acid sequence 109 - 145 of β - hcg was prepared synthetically using the solid state synthesis procedure of tregear , g . w . et al ., biochem . 16 , 2817 ( 1977 ). this third peptide is identified in table 3 as p - 3 . highly purified hcg was used in all immunological experiments where reference was made to intact hcg . conjugates of the three peptides were prepared to keyhole - limpet hemocyanin ( klh ) using tolulene diisocyanate . a peptide - carrier ratio of 4 - 6 peptides per 100 , 000 daltons of carrier was obtained for different conjugates prepared according to amino acid analyses . rabbits were immunized with conjugates by three multiple site intramuscular injections of 1 . 0 mg . of conjugate in 0 . 5 ml . of saline emulsified with an equal volume of freund &# 39 ; s complete adjuvant . injections were given at 3 weeks intervals and weekly blood samples were collected from 3 - 20 weeks of immunization . antisera to all conjugates were monitored for antibody levels by reacting dilutions of sera with i 125 labeled hcg ( chloramine t method ) at 4 ° c . for 5 days and precipitating immune complexes with sheep anti - rabbit gamma globulin serum . antibody levels were determined by assessing dilution curves in which a linear correlation between dilution and binding of labelled antigen at equilibrium occurred . at least 3 points in each curve were used in calculating levels . these levels were expressed as μg . hcg bound per ml . of undiluted serum calculated by multiplying mass of labelled antigen bound by serum dilution . a radioimmunoassay system employing i 125 hcg and antisera raised to peptide conjugates was used to determine the relative ability of hcg and peptides to compete with labeled hcg . peak antibody levels from each rabbit were evaluated in these studies . antigens and antisera contained in phosphate - buffered saline ( ph 7 . 4 ) bsa ( 1 %) were added to test tubes and incubated at 4 ° for 5 days . separation of free and bound tracer hcg was accomplished by the addition of sheep anti - rabbit gamma globulin serum and further incubated for 48 hours followed by centrifugation . assessment of parallelism of dose response curves was accomplished using methods described by rodbard , d . in : odell , w . d . and daughaday , w . h ., eds ., &# 34 ; competitive protein binding assays ,&# 34 ; j . b . lippincott , phila . pa . ( 1971 ). the ability of unlabelled hcg and peptides to compete with i 125 hcg for antibody binding sites was expressed as moles of unlabeled antigen , per mole of unlabeled hcg , required to reduce the binding of labeled hcg by 50 %. for this purpose molecular weights for hcg , p - 1 , p - 2 , and p - 3 of 38 , 000 , 7 , 000 , 3 , 990 , and 3 , 990 respectively were used . the molecular weight of the p - 1 peptide was an estimate since the contribution of the 4 carbohydrate chains to its size was not determined . four radioimmunoassays were performed with each of the 11 antisera studied and the results presented as the mean of the four values . parallel dose response curves of hcg and peptides were observed in all radioimmunoassays . in the assay system employed , 200 - 400 moles of unlabeled hcg was required per mole of labeled hcg at 50 % binding of the latter to antisera . there was no detectable difference among antisera to the 3 peptide conjugates in the ability of intact hcg to compete with labeled hormone for antibody binding sites . data obtained from comparing the ability of hcg and peptides to compete with i 125 hcg for binding to anti - peptide sera revealed some qualitative differences in the antisera ( table 2 ). much larger quantities of p - 2 peptide and p - 3 peptide were required to reduce i 125 hcg binding than was required by p - 1 peptide when sera against the p - 1 peptide was tested . while similar quantities of p - 2 and p - 3 peptides were required to inhibit one mole of labeled hcg binding , these were 2 - 10 times the amounts required by the p - 1 peptide . differences in the quantities of peptides required to compete with an equivalent mass of labeled hcg were less using antisera raised to carbohydrate - free natural peptide ( p - 2 ). more p - 1 peptide was needed for an equal reduction in binding than the other 2 peptides . no significant difference could be detected in the quantities of p - 2 or p - 3 peptides required among the 3 antisera tested . approximately 1 . 5 - 2 . 0 times as much p - 1 peptide was required to compete equally with i 125 hcg for antibodies raised to the p - 3 peptide but p - 2 peptide reacted nearly as well as did the synthetic peptide . despite low levels of antibodies obtained in this study , the carbohydrate - containing peptide was not more immunogenic than those without this moiety when conjugates to both were prepared in the same manner table 3______________________________________mean quantities of hcg and 109 - 145 c - terminal β - hcgpeptides required to compete with i . sup . 125 hcg at 50 % binding of labelled hormoneunlabelled antigens hcg p - 1 p - 2 p - 3antisera mol / mol mol / mol mol / mol mol / molrabbit hcg i . sup . 125 hcg i . sup . 125 hcg i . sup . 125 hcg i . sup . 125no . ( x ± se ) ( x ± se ) ( x ± se ) ( x ± se ) ______________________________________anti p - 1 78 284 ( 12 . 6 ) 430 ( 11 . 8 ) 4565 ( 200 . 8 ) 3628 ( 154 . 1 ) 79 350 ( 13 . 5 ) 404 ( 18 . 5 ) 855 ( 33 . 4 ) 881 ( 42 . 2 ) 171 403 ( 17 . 7 ) 343 ( 9 . 9 ) 899 ( 35 . 1 ) 759 ( 37 . 1 ) 173 377 ( 16 . 5 ) 320 ( 13 . 9 ) 1448 ( 72 . 4 ) 1536 ( 73 . 7 ) anti p - 2 93 247 ( 11 . 8 ) 385 ( 18 . 2 ) 264 ( 12 . 5 ) 268 ( 12 . 73 ) 94 294 ( 14 . 1 ) 431 ( 15 . 5 ) 362 ( 15 . 2 ) 329 ( 13 . 8 ) 252 201 ( 9 . 6 ) 296 ( 12 . 4 ) 216 ( 7 . 7 ) 205 ( 9 . 0 ) anti p - 3405 496 ( 23 . 6 ) 998 ( 47 . 4 ) 628 ( 27 . 6 ) 309 ( 13 . 6 ) 411 489 ( 20 . 5 ) 1200 ( 50 . 4 ) 678 ( 29 . 7 ) 413 ( 16 . 1 ) 416 364 ( 13 . 1 ) 581 ( 20 . 9 ) 400 ( 14 . 4 ) 271 ( 12 . 8 ) 417 340 ( 14 . 9 ) 474 ( 18 . 4 ) 176 ( 6 . 8 ) 105 ( 4 . 6 ) ______________________________________ from these studies , it can be concluded that although antibodies to carbohydrate free peptides are qualitatively different than those to the natural peptide , antisera generated to the synthetic peptide reacted with hcg as well as antisera to natural peptides and equivalent to natural and synthetic peptides elicited similar anti - hcg levels in rabbits . in this example , a polypeptide fragment structure having an -- sh group is activated utilizing the following reagent : ## str9 ## a solution of the reagent ( 1 . 2 eq . per -- sh group in the polypeptide ) in a suitable water miscible organic solvent , such as dioxane , is added to a solution of the polypeptide fragment structure , e . g . structure ( xii ) ( which has had its amino groups blocked ) in aqueous buffer at ph 6 . 5 . after 2 hours , the solvent is removed at a temperature of less than 30 ° c . under vacuum , and to the residue are added water and ethyl ether ( 1 : 1 ). the aqueous layer is separated and its ph adjusted to approximately 8 . 5 by the addition of sodium hydroxide solution and this alkaline mixture is added rapidly to an aqueous solution of the carrier , e . g . the above described influenza subunit , maintained at ph 8 . 5 by a suitable buffer . after a further 4 hours , the conjugate is isolated , by gel filtration . with the following reagent : ## str10 ## a solution or suspension of a carrier containing no sulfhydryl groups such as flagellin in a suitable aqueous buffer at a ph 6 . 5 is treated with the required ( 1 . 2 eq /- nh 2 desired to be reacted ) amount of a solution of the reagent in dimethylformamide . after 1 hour , the modified carrier is isolated by column chromatography and added to buffer at ph 6 - 7 . this is then treated with a solution of the selected fragment ( containing sulfhydryl groups ) in the same buffer and the reaction is allowed to proceed for 12 hours before the conjugate is isolated by column chromatography . modification of non - sulfhydryl containing peptide fragments [ e . g . structure ( ii )] or a carrier such as flagellin to a sulfhydryl containing one via &# 34 ; thiolactonization &# 34 ; is carried out as follows : the peptide is dissolved in a 1 m aqueous solution of imidazole containing 0 . 5 % of ethylenediamine tetraacetic acid at a ph of 9 . 3 under an atmosphere of nitrogen and a 100 fold excess of n - acetylhomocysteine thiolactone is added in three portions at eight hour intervals . after a total of 30 hours , the ph is adjusted to 3 - 4 with acetic acid and the modified peptide is isolated by gel chromatography and elution with 0 . 5 m acetic acid . the carrier protein is reacted with the n - hydroxysuccinimide ester of a halo -( either chloro , bromo or iodo ) acetic acid in the general procedure described in the first part of example xxviii thus yielding a modified carrier containing the required number of halomethyl alkylating groups as desired . to a solution of the sulfhydryl containing peptide [ e . g . structure ( xii )] in a phosphate buffer at ph 6 . 5 - 7 . 0 under nitrogen at room temperature is added an aqueous solution or suspension of the modified carrier prepared above . the mixture is stirred for 12 hours . it is then washed with ethyl acetate and the conjugate contained in the aqueous phase is purified by dialysis , gel chromatography and lyophilization . should neither the carrier nor polypeptide fragment contain a sulfhydryl group , one may be introduced into either of them by the standard procedures such as &# 34 ; thiolactonization &# 34 ; described above under example xxix .
modified hormones or fragments of hormones are useful in producing antibodies when administered to an animal . said antibodies in turn cause neutralization of endogenous natural protein hormones . the modification may be accomplished by attaching various kinds of modifying groups to the hormone or fragment . modification may , for example , be achieved by chemically coupling diazosulfanilic acid groups to the hormone or fragment . the protein hormones to which this procedure can be applied are mammalian protein reproductive hormones such as , for example , follicle stimulating hormone , or human chorionic gonadotropin . these modified hormone or fragment may be administered to animals for the purpose of contraception , abortion , or treatment of hormone related disease states and disorders .