PURIFICATION AND CHARACTERIZATION OF 2 SERINE COLLAGENOLYTIC PROTEASES FROM CRAB PARALITHODES-CAMTSCHATICA

Two enzymes possessing collagenolytic activity were isolated from the hepatopancreas of crab Paralithodes camtschatica by ammonium sulfate f ractionation and DEAE-Sepharose chromatography. It was shown that the specific activities of proteases A and C toward insoluble collagen wer e equal to 400 and 300 Mandl units/mg protein, respectively. The mol. wt of homogenous proteases A and C determined by gradient polyacrylami de gel electrophoresis in the presence of SDS and 2-mercaptoethanol we re equal to 30 and 24 kDa, respectively. The isoelectric point values for the enzymes were determined as 2.5 and 2.9. Both enzymes lack carb ohydrates. The amino acid compositions of two crab proteases were meas ured. The optimal conditions for the enzyme catalysis and the catalyti c constants for collagenolytic proteases A and C with respect to Bz-Ar g-pNA and Bz-Tyr-OEt have been determined. Inhibition data led to clas sification of the purified enzymes as serine proteases.