the present invention will be further illustrated below in connection with the examples . in the examples described hereinafter , where the particular experiment conditions are not otherwise noted , they will follow the conventional conditions well known to the person of skill in the art , such as the conditions and experimental steps described in molecular cloning : a laboratory manual , sambrook et al ( ed . ), new york , cold spring harbor laboratory press , 1989 , an conventional manual for laboratory animals ( national center for standard laboratory animals , november , 2004 ), and a manual of basic technique , 5 th edition ( john wiley & amp ; sons , inc ., 2005 ), or follow the conditions and experimental steps recommended by the manufacture . the particular experimental methods in the examples are exemplified by the protein hf vii - egf1 , and the experimental methods for other human - originated egf domain proteins ( prt2 to prt1498 in table 1 ) are performed with reference to those for the protein hf vii - egf1 . nucleotide sequences for the expressed proteins of interest can be obtained from the databases on the web ( http :// www . uniprot . org / or http :// www . ncbi . nlm . nih . gov /). acquisition of the gene for the fusion protein rfp - hf vii - egf1 with a red fluorescent protein ( rfp ) tag 1 . the primers for pcr amplification as shown below were synthesized ( by invitrogen biological technology co . ltd . ): 2 . obtaining the coding sequences for hf vii - egf1 and rfp by pcr amplification the pcr amplification was performed with primers 2 and 4 using a plasmid comprising the hf vii cds region ( fulengen co . ltd ., guangzhou ) as the template . a bamh i restriction site introduced into the sequence of primer 4 , and an enzymatic cleavage site for the recombinant tobacco mosaic virus proteinase ( rtev ) and a restriction site for bsp119 i were introduced into the sequence of primer 2 , in order to facilitate replacement with the expressible sequences for expressing other human - originated egf domain proteins ( prt2 to prt1498 in table 1 ). the pcr reaction system ( 50 μl ) was as follows : the reaction condition for the pcr amplification was set with reference to the instruction of primestar dna polymerase ( purchased from takara ): pre - denaturation at 98 ° c . for 2 min , 30 cycles of denaturation at 98 ° c . for 10 sec , annealing at 55 ° c . for 15 sec , and elongation at 72 ° c . for 30 sec , followed by elongation at 72 ° c . for 4 min . the amplified products were analyzed with 2 % agarose gel electrophoresis , the dna fragments comprising the coding sequence for hf vii - egf1 was obtained ( see fig1 ), and the fragments of interest was recovered according to the instruction of a gel recovery kit ( purchased from omega ). the pcr amplification was performed with primers 1 and 3 using a plasmid comprising the coding sequence of the gene for the rfp protein ( purchased from takara ) as the template . an nde i restriction site was introduced into the sequence of primer 1 . the reaction system was set up with reference to that for obtaining the dna fragment encoding for hf vii - egf1 . the reaction condition for the pcr amplification was set up with reference to the instruction of primestar dna polymerase : pre - denaturation at 98 ° c . for 2 min , 30 cycles of denaturation at 98 ° c . for 10 sec , annealing at 55 ° c . for 15 sec , and elongation at 72 ° c . for 1 min , followed by elongation at 72 ° c . for 4 min . the amplified products were analyzed with 2 % agarose gel electrophoresis , the dna fragment comprising the coding sequence for rfp was obtained , and the fragment of interest was recovered according to the instruction of a gel recovery kit ( purchased from omega ). 3 . amplification of the gene encoding for the fusion protein rfp - hf vii - egf1 by overlapping pcr . a overlapping pcr amplification was performed with primers 1 and 4 using the dna fragment obtained from the two pcr amplifications mentioned above as templates , yielding a fusion gene fragment rfp - hf vii - egf1 which comprises a coding sequence for the rfp - tev enzymatic cleavage site and the human coagulation factor vii - egf1 protein . the pcr reaction system ( 50 μl ) was as follows : the reaction condition for the pcr amplification was set up with reference to the instruction of primestar dna polymerase : pre - denaturation at 98 ° c . for 2 min , 30 cycles of denaturation at 98 ° c . for 10 sec , annealing at 55 ° c . for 15 sec , and elongation at 72 ° c . for 1 . 5 min , followed by elongation at 72 ° c . for 4 min . the amplified products were analyzed with 2 % agarose gel electrophoresis , the fragment comprising the sequence encoding for rfp - hf vii - egf1 was obtained ( see fig2 ), and the fragment of interest was recovered according to the instruction of a gel recovery kit ( purchased from omega ). construction of the recombinant prokaryotic plasmid for expressing the fusion protein rfp - hf vii - egf1 1 . pre - treatment of the rfp - hf vii - egf1 gene and the prokaryotic expression vector pet19b the rfp - hf vii - egf1 gene fragment obtained in example 1 and the prokaryotic expression vector pet19b ( the product from novagen , the plasmid had been modified to carry a gene encoding for a red fluorescent protein ) were individually double digested with the restriction endonucleases nde i and bamh i ( both purchased from takara or fermentas ) at 37 ° c . overnight , and the reaction systems were established as follows : after completion of the double digestion , the reaction products were analyzed with 1 % agarose gel electrophoresis and the fragments of interest were recovered under the ultraviolet lamp of a gel imaging system according to the instruction of a gel recovery kit ( purchased from omega ). 2 . ligation of the rfp - hf vii - egf1 gene to the prokaryotic expression vector pet19b and transformation ( 1 ) the gene fragment rfp - hf vii - egf1 and the prokaryotic vector fragment obtained in the above steps were quantified approximately and then subjected to ligation according to the ligation reaction principle where a ratio of the molecule number of the gene fragment to the molecule number of the prokaryotic vector is 3 : 1 . the ligation reaction system was set up as follows : ( 2 ) the entire ligation reaction was proceeded at 16 ° c . overnight treated with t4 dna ligase ( purchased from fermentas ). the gene fragment rfp - hf vii - egf1 amplified above was inserted into the prokaryotic expression vector pet19b and the construction of the recombinant prokaryotic plasmid was schematically shown in fig3 . ( 3 ) the ligation product was transformed into the competent cells ( prepared according to molecular cloning : a laboratory manual ) of e . coli top10 ( purchased from invitrogen company ). the main steps of the procedure for transforming the ligation product were as follows : 1 ) 5 μl of the ligation product was pipetted into 100 μl of the competent cells of e . coli top10 placed in a 1 . 5 ml eppendorf tube , and the negative control is 100 μl of the competent cells of e . coli top10 placed in a 1 . 5 ml eppendorf tube ; 3 ) the competent cells were shocked in a metal bath at 42 ° c . for 90 s ; 4 ) the tubes were transferred rapidly into an ice - bath to be cooled for 2 min ; 5 ) 900 μl of soc medium ( 10 g peptone , 5 g yeast extract , 0 . 5 g nacl , 0 . 186 g kcl , 0 . 95 g mgcl 2 , dissolved with ddh 2 o and made up to a volume of 980 ml , autoclaved , cooled to room temperature and then 20 ml of sterile 20 % aqueous glucose solution was added ) was added , and placed on ice ; 6 ) the tubes were incubated at 37 ° c . for 1 h with shaking at 180 rpm ; 7 ) the bacterial suspension was centrifuged at 4000 × g for 3 min , and the excessive medium was removed except 200 μl supernatant was kept . 200 μl of the remaining supernatant was used to resuspend the bacteria ; 8 ) the resuspended transformants were plated uniformly onto the solid lb medium containing 0 . 1 g / ml of ampicillin and incubated in a constant - temperature incubator at 37 ° c . overnight . the single clone of the transformed e . coli top 10 mentioned above was picked , cultured in a small quantity and subjected to plasmid extraction with a plasmid extraction kit ( purchased from omega ), followed by double digestion set forth in the steps of the present example step 1 . the result of the double digested product resolved by gel - electrophoresis is shown in fig4 . the sizes of the two bands produced by the enzymatic digestion are consistent with those of the expected products , demonstrating the success of construction of the plasmid of interest . the plasmids which had been identified by double digestion to be correct ones were send to beijing genomics institute for sequencing of the inserted fusion gene fragment . finally , the recombinant prokaryotic plasmid comprising the rfp - hf vii - egf1 gene with the correct sequencing result was designated as pet19brfp - hf vii - egf1 . obtaining the fusion genes for the rfp fusion proteins of other human - originated egf domain proteins ( prt2 to prt1498 in table 1 ) with a red fluorescent protein ( rfp ) tag since all of the expressed sequences of the human - originated egf domain proteins ( prt1 to prt1498 in table 1 ) set forth in the present invention have been published , the expressible nucleotide sequences can be obtained directly by artificial synthesis . in this example , synthesis of the gene fragments was outsourced respectively to the commercial companies such as beijing genomics institute , genewiz ( beijing ) co . ltd ., etc . when synthesized , a bsp119 i restriction site was introduced upstream of all these gene fragments , to facilitated construction of prokaryotic expression plasmids . electrophoresis of an overlapping pcr amplification of the gene sequence encoding for the fusion protein rfp - hf vii - egf2 is shown in fig5 . construction of the prokaryotic recombinant plasmids for expression of the rfp fusion proteins of other human - originated egf domain proteins ( prt2 to prt1498 in table 1 ) the gene fragments for other human - originated egf domain proteins and the recombinant plasmid pet19brfp - hf vii - egf1 constructed in example 2 were double digested with the restriction endonucleases bsp119 i and bamh i ( both purchased from takara or fermentas ) at 37 ° c . overnight . 2 . other steps for ligation of the expression genes to the plasmid and identification were performed with reference to example 2 . 1 . the recombinant plasmid pet19brfp - hf vii - egf1 constructed in example 2 was transformed into e . coli bl21 ( de3 ) ( purchased from invitrogen ); the single clone was picked into the lb medium containing 0 . 1 g / ml ampicillin and incubated at 37 ° c . with shaking at 185 rpm to od 600 of about 0 . 6 , and 1 ml of the bacterial suspension was taken and frozen at − 20 ° c . then , iptg ( isopropyl - β - d - thiogalactoside ) was added to the remaining bacterial suspension at a final concentration of 0 . 8 mm . the incubation proceeded for 6 h and 1 ml of the bacterial suspension was taken and frozen at − 20 ° c . 2 . the above - mentioned samples before and after iptg induction were assayed by sds - page electrophoresis with 5 % of the stacking gel and 12 % of the separating gel , in order to analyze expression of the protein of interest ( see fig6 ). the result indicated that the protein was expressed normally . 1 . the bacterium rfp - hf vii - egf1 - pet19bbl21 -( de3 ) was cultured on a large scale according to the method in example 5 , induced by addition of iptg , and cultured overnight at 18 ° c ., with shaking at 175 rpm . 2 . the above - mentioned bacterial suspension was centrifuged at 4000 × g for 3 min to collect the bacteria . the bacterial pellet was washed by resuspension in the ew buffer ( 20 mm sodium phosphate , 500 mm nacl , 1 mm dtt , 0 . 1 mm pmsf , ph 7 . 4 ). the bacterial suspension was centrifuged at 4000 × g for 3 min , and the supernatant was discarded . again , the bacterial pellet was resuspended with 10 ml of the ew buffer . 3 . the bacteria were disrupted by sonication ( power : 300 w ; duration for sonication : 10 s ; interval : 10 s ; total time for sonication : 3 min ; performed in ice - bath ). after completion of the sonication , the bacterial suspension was centrifuged at 48 , 400 × g at 4 ° c . for 1 h . the supernatant was collected and placed on ice . 4 . the chromatographic column was preloaded according to the instruction of co 2 + purification system ( talon metal affinity resin , clontech company product ), and the sample was loaded . the column was washed twice with 10 ml ew buffer and the protein impurities were washed out with 10 mm imidazole solution . finally , the protein was eluted with 100 mm imidazole . 5 . the eluent comprising the proteins of interest was ultrafiltrated with tris - cl buffer ( ph 7 . 4 ), for buffer exchange and concentration . after ultrafiltration , the high concentration of the fusion protein rfp - hf vii - egf1 can be obtained . it was shown by protein quantitation that about 15 mg of the proteins of interest with more than 95 % of purity can be obtained per litre of the expressing bacterium suspension . enzymatic cleavage of the fusion protein rfp - hf vii - egf1 and purification of the recombination protein hf vii - egf1 1 . the reasin ni column ( ni column purchased from ge ) was treated as follows : 200 μl of the ni column mix was pipetted into a 1 . 5 ml ep tube ( axygen ) and centrifuged at 700 × g for 2 min , the preservative solution for the reasin ni column ( 20 % ethanol ) was discarded , then , the ni column was washed twice with 1 ml deionised water , followed by equilibration of the ni column with 1 ml binding buffer ( 0 . 5 m nacl , 20 mm phosphate buffer , ph 7 . 4 ). 2 . 450 μa of 3 μg / μl fusion proteins were mixed individually with the treated ni column to homogeneity after equilibration of the ni column , co - incubated at 4 ° c . for 1 h on a vertical rotary mixer . 3 . after completion of incubation , the mixture was centrifuged at 4 ° c . at 700 × g for 3 min after completion of centrifugation , ni beads obtained by centrifugation were washed twice with 500 μa of binding buffer . ni beads were collected after completion of washing . 4 . the beads were resuspended with 423 μl of binding buffer . after resuspending and mixing well , the resultant mixture was subjected to cleavage at 4 ° c . with the rtev proteinase ( purchased from shanghai sangon ). the mixture was placed on a vertical rotary mixer overnight with the time of period limited to 10 h . after completion of the enzymatic cleavage , the mixture was centrifuged at 700 × g at 4 ° c . for 5 min . after completion of centrifugation , the supernatant was collected as the recombination protein hf vii - egf1 . the picture of tricien gel analysis for identifying the recombination protein hf vii - egf1 obtained after enzymatic cleavage of the fusion protein rfp - hf vii - egf1 with rtev is seen in fig7 . the enzymatic cleavage system was set up as follows : prokaryotic expression of the other recombination human - originated egf domain proteins ( prt2 to prt1498 in table 1 ) and purification of the same the other human - originated egf domain proteins ( prt2 to prt1498 in table 1 ) can be expressed prokaryotically and then purified with the same methods as those in examples 5 - 7 . partial profiles are shown in fig6 to 25 . construction of the recombinant eukaryotic plasmid for expressing the fusion protein rfp - hf vii - egf1 1 . the primers for pcr amplification as shown below were synthesized ( by invitrogen biological technology co . ltd . ): the pcr amplification was performed with primers 1 and 2 using the plasmid pet19brfp - hf vii - egf1 constructed in example 2 as the template . a bamh i restriction enzyme cutting site and a kozak sequence were introduced into the sequence of primer 1 , and an xho i restriction enzyme cutting site was introduced into the sequence of primer 2 . the pcr reaction was performed with reference to example 1 . 3 . construction of the recombinant plasmid for eukaryotic expression of the fusion protein rfp - hf vii - egf1 the cloned gene fragment rfp - hf vii - egf1 and the eukaryotic expression vector pcdna3 . 1 (+) ( the product from novagen ) were double digested with the restriction endonucleases bamh i and xho i ( both purchased from takara or fermentas ), and the reaction systems were set up with reference to example 2 . the steps for ligating the gene fragment to the eukaryotic expression vector and for transforming and identifying the recombinant plasmid were performed with reference to example 2 . finally , the recombinant plasmid comprising the rfp - hf vii - egf1 gene with the correct sequencing result was designated as pcdna3 . 1 - rfp - hf vii - egf1 . the plasmid map of the recombinant plasmid is seen in fig2 . construction of a stable cell line for expressing the fusion protein rfp - hf vii - egf1 dg44 cells ( purchased from atcc ) were cultured in the α - mem complete culture medium ( containing l - glutamine , ribonucleic acid and deoxyribonucleic acid , purchased from hiclony ) supplemented with 10 % fbs ( fetal bovine serum , purchased from hiclony ). on the day before transfection , dg44 cells were seeded in a 6 - well plate at 4 × 10 5 cells / ml with 2 ml per well . cells were transfected by using liposome method following the instruction of lipofectamine ™ 2000 kit ( purchased from invitrogen ). the detailed steps are as follows : 1 ) the cell culture medium was replaced with serum - free α - mem medium , 2 ml / well . 2 ) 4 . 0 μg of the recombinant eukaryotic expression plasmid pcdna3 . 1 - rfp - hf vii - egf1 constructed in example 9 was mixed with 250 μl opti - mem , while 10 μl of lipofectamine ™ 2000 was mixed with 250 μl of opti - mem and incubated for 5 min 3 ) the two solutions were mixed well and incubated for 20 min . the liposome complexes were added into the well with cells , gently mixed , placed into an incubator and cultured at 37 ° c . 4 ) after 5 h , the medium was replaced with the α - mem complete culture medium supplemented with 10 % fbs . after 24 h of transfection with the recombinant plasmid , the cells were transferred into 100 mm petri dishes at a ratio of 1 : 2000 . g418 ( purchased from gibco ) was added at a final concentration of 800 μg / ml for screening . cells transfected with an empty vector or not transfected were used as controls . after 15 days , the single clones were picked into and cultured in 24 - well plates , and sequentially transferred into 6 - well plates and into 100 mm petri - dishes for expanding culture once cellular confluence was reached . when the cell confluency was 90 %, cells were frozen at a rate of 1 : 4 in fbs with 10 % dmso ( purchased from gibco ). the picked positive cell clones were identified by the genomic pcr and rt - pcr . the fragment of interest could be amplified by both of the techniques , which demonstrated that the fusion gene has been integrated into the genome of the cell and a functional mrna is transcribed . the stable cell line obtained was designated as dg44 - rfp - hf vii - egf1 . 1 . the dg44 - rfp - hf vii - egf1 cells were cultured in the α - mem complete culture medium containing 10 % fbs supplemented with 400 μg / ml g418 , and passaged into 10 plates . 2 . when the cell confluency in each plate reached to more than 90 %, the α - mem complete culture medium containing 10 % fbs was replaced with cho serum - free medium , and supplemented with vitamin k ( sigma ) to a final concentration of 1 μg / ml . 3 . after 3 days of cultivation , the cellular pellet was collected and disrupted . then , the supernatant was obtained by centrifugation , purified by cobalt ion affinity chromatography and identified by sds - page plus western blot . the steps were referred to those in example 6 . enzymatic cleavage of the eukaryotically expressed fusion protein rfp - hf vii - egf1 and recovery of hf vii - egf1 eukaryotic expression of the other human - originated egf domain proteins ( prt2 to prt1498 in table 1 ) and purification of the same according to the methods of examples 9 - 10 , the eukaryotic expression plasmids for the rfp fusion proteins of other human - originated egf domain proteins ( prt2 to prt1498 in table 1 ) were constructed and the cell lines stably expressing these fusion proteins were established . according to the methods of examples 11 - 12 , the eukaryotically expressed fusion proteins were collected and subjected to enzymatic cleavage , and the other human - originated egf domain proteins ( prt2 to prt1498 in table 1 ) were finally obtained . 1 . e . coli dh5a was exemplified . e . coli dh5a was streaked and cultured on lb solid medium . then , a typical clone was picked and inoculated into common lb liquid medium , cultured at 37 ° c . with shaking at 185 rpm until the logarithmic growth phase was reached ( od 600 of about 0 . 5 ). the bacterial culture was centrifuged at 4000 × g for 3 min , the supernatant was discarded , and the thalli were resuspended with fresh lb medium . 2 . the above - mentioned bacterial suspension was diluted and inoculated into a 96 - well plate with the total volume of 100 μl per well and a bacterial count of 5 × 10 5 cfu / ml . 3 . the recombinant protein hf vii - egf1 was added to the above - mentioned wells with the final protein concentration in the well of the highest protein concentration being 50 μg / ml . basing on this final concentration , a two - fold serial dilution was performed till a protein concentration gradient consisting of 50 , 25 , and 12 . 5 μg / ml was set up . three parallel wells were set up for each concentration in the gradient . 4 . the above - mentioned 96 - well plate was placed and cultured at 37 ° c . in shaking incubator shaking at 175 rpm . samples were taken every 30 min , the absorbance values were determined at 600 nm wavelength under a ultra violet spectrophotometer , and an inhibition curve was plotted . judgement on mic : after 8 h of cultivation , the growth was observed with naked eyes or judged under the ultra violet spectrophotometer at a wavelength of 600 nm . the minimal inhibitory concentration mic is defined as the lowest concentration of the recombinant protein at which there is no growth of the bacteria . the growth curve of e . coli dh5a treated with the recombinant protein hf vii - egf1 is seen in fig2 . the curve indicates that the recombinant protein hf vii - egf1 exhibits a significant inhibitory effect on the growth of e . coli dh5a , with the mic being 12 . 5 μg / ml . determination of antibacterial activities of the other human - originated egf domain proteins ( prt2 to prt1498 in table 1 ) according to the experimental procedures in example 14 , the minimal inhibitory concentrations ( mic , μg / ml ) of the other human - originated egf domain proteins ( prt2 to prt1498 in table 1 ) for e . coli dh5a were determined . the results are shown in table 2 : it can be known from the above table that : all of the human - originated egf domain proteins ( prt1 to prt1498 in table 1 ) have an inhibitory effect on e . coli dh5a . effect of the human - originated egf domain proteins ( prt1 to prt1498 in table 1 ) such as the recombination protein hf vii - egf1 , etc on the growth of various gram - negative bacteria 1 . gram - negative bacteria , such as e . coli bl21 , pseudomonas aeruginosa , klebsiella pneumonia , enterobacter cloacae , aeromonas hydrophila , citrobacter diversus , moraxella catarrhalis , proteus mirabilis , proteus vulgaris , serratia marcescens , etc were streaked on solid lb medium and cultured respectively . then , typical clones were picked , inoculated into common liquid lb medium respectively , and cultured at 37 ° c . with shaking at 185 rpm until the mcfarland specific turbidity was 0 . 5 . the bacterial culture of each of gram - negative bacteria was centrifuged at 4000 × g for 3 min , the supernatant was discarded , and the thalli were resuspended with fresh lb medium . 2 . the above - mentioned bacterial suspensions were diluted and inoculated into 96 - well plates with the final concentration of the bacterial suspension being 5 × 10 5 cfu / ml per well . 3 . each of the purified human - originated egf domain proteins ( prt1 to prt1498 in table 1 ) was added to each of the above wells and subjected to two - fold serial dilution in concentration . three parallel wells were set up for each concentration in the gradient . 4 . the above - mentioned 96 - well plates were placed and cultured at 37 ° c . in shaking incubator shaking at 175 rpm . judgement on mic : after 10 h of cultivation , the growth was observed with naked eyes or judged under the ultra violet spectrophotometer at a wavelength of 600 nm . the minimal inhibitory concentration mic is defined as the lowest concentration of the recombinant protein at which there is no growth of the bacteria . the results are shown in table 3 : conclusion : it can be known from the above table that : all of the recombinant human - originated egf domain proteins ( prt1 to prt1498 in table 1 ) set forth in the present invention exhibit inhibitory effects on various gram - negative bacteria , such as , e . coli , pseudomonas aeruginosa , klebsiella pneumonia , enterobacter cloacae , aeromonas hydrophila , citrobacter diversus , moraxella catarrhalis , proteus mirabilis , proteus vulgaris , serratia marcescens , etc . silver staining detection of endotoxin ( lps ) hydrolyzed by the human - originated egf domain proteins ( prt1 to prt1498 in table 1 ) such as the recombination protein hf vii - egf1 , etc . 1 . the e . coli eh100 lps ( sigma ) samples were respectively incubated with the obtained human - originated egf domain proteins ( prt1 to prt1498 in table 1 ) such as the recombination protein hf vii - egf1 , etc . ; and the control group was the lps sample incubated with tb s buffer . the incubation lasted overnight . then , the centrifugation was performed to collect the pellet . 2 . the 1 × loading buffer for lps ( 0 . 05 mol / l tris - hcl , containing 10 g / l sds , 100 g / l sucrose , 0 . 5 % β - mercaptoethanol , 10 mg / l bromophenol blue , ph 6 . 8 ) was mixed with the sample of the treated pellet and incubated on a metal bath at 100 ° c . for 5 min 3 . 15 % separating gel ( containing 4 mol / l urea , bio - rad with a thickness of 1 . 0 mm , the detailed composition as follows : 1 . 15 ml of deionized water , 2 . 5 ml of 30 % acrylamide , 1 . 3 ml of 1 . 5 mol / l tris - hcl ( ph 8 . 8 , containing 10 % sds ), 50 μl of 10 % ammonium persulfate , 4 μl of temed ) was mixed well and prepared . the top of the separating gel was overlaid with water . 4 . 5 % stacking gel was prepared as follows : 1 . 42 ml of deionized water , 0 . 33 ml of 30 % acrylamide , 0 . 25 ml of 1 mol / l tris - hcl ( ph 6 . 8 , containing 10 % sds ), 20 μl of 10 % ammonium persulfate , 2 μl of temed ) were mixed well and poured . a ten - well comb was quickly inserted . 5 . after the gel was prepared , the samples were loaded . then , the gel was run at a voltage of 120 v to separate the samples . after running , the gel was taken to start silver staining . the gel was transferred into a tray washed thoroughly with deionized water , followed by washing the gel three times with deionized water . 6 . after completion of the washing , the gel was fixed with 50 ml of fixation solution ( 30 % alcohol , 10 % glacial acetic acid , 7 g / l periodic acid ) for oxidation at room temperature for 25 min after completion of the fixation , the gel was washed three times each time with deionized water for 5 min 7 . after completion of the washing , the gel was stained in 100 ml of 1 g / l agno 3 at room temperature for 40 min after completion of the staining , the gel was washed one time with ddh 2 o . 8 . the gel was transferred into 50 ml of 30 g / l na 2 co 3 pre - chilled on ice , to which 0 . 02 % formaldehyde was added just before visualization . when the band appeared or began to become dark , the reaction was stopped by adding 6 ml glacial acetic acid . the stopping solution was removed upon completion of the termination reaction and the gel was kept in deionized water . the silver staining picture was exemplified by the protein hf vii - egf1 , as shown in fig2 . after treated with hf vii - egf1 , the lps band is obviously decreased and becomes weak , indicating that the protein hf vii - egf1 eliminates the majority of lps . the silver staining pictures of prt2 to prt1498 in table 1 are similar to that in fig2 . this indicated that the human - originated egf domain proteins ( prt1 to prt1498 in table 1 ) described in the present invention can hydrolyze lps and may be used in preparation of a medicament for treating endotoxemia caused by the gram - negative bacteria .
in the invention , the minimum inhibitory concentrations of human - originated egf domain proteins against different gram - negative bacteria are detected with the in vitro antibacterial activity . it has been shown that the human - originated egf domain proteins have an obvious inhibitory effect on the gram - negative bacteria , so as to develop a novel class of medicaments for treating gram - negative bacteria infection . it has been demonstrated by silver staining that the human - originated egf domain proteins have the effect on hydrolyzing and eliminating the endotoxin , which facilitates the development of a novel class of medicaments for treating endotoxemia . the amino acid sequences of the human - originated egf domain proteins are the one described in seq id no : 1 in the sequence listing , or those having homology of over 50 % to the amino acid sequence described in seq id no : 1 .