comparison of two cysteine endopeptidases from latices of morrenia brachystephana griseb and morrenia odorata hook et arn lindley asclepiadaceae the properties of morrenain b ii a proteinase isolated from the latex of morrenia brachystephana were compared with those of morrenain o ii a proteinase obtained from the latex of morrenia odorata both peptidases were purified to homogeneity by acetone precipitation followed by cation exchange chromatography the enzymes have pi values higher than 93 and similar molecular masses close to 26 kda as determined by sdspage they display maximum proteolytic activity within an alkaline ph range and also exhibit esterolytic activity the nterminal sequences of morrenain o ii and morrenain b ii show a high degree of homology between each other and to other cysteine plant proteinases