Iy. Sakharov et al., PURIFICATION AND CHARACTERIZATION OF 2 SERINE COLLAGENOLYTIC PROTEASES FROM CRAB PARALITHODES-CAMTSCHATICA, Comparative biochemistry and physiology. B. Comparative biochemistry, 108(4), 1994, pp. 561-568
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.