Studies on Fin Whale Pancreatic Proteases: III. Properties of Purified Fin Whale Anionic Chymotrypsin

• Main Author: MATSUOKA, Atsushi KOIDE and Yoshitaka
• Format: Text
• Language: English
• Published: Oxford University Press 1970
• Subjects: Articles; Archibald; Fin whale
• Online Access: http://jb.oxfordjournals.org/cgi/content/short/68/1/1

Some physical and enzymatic properties were studied on the purified fin whale anionic chymotrypsin which was homogeneous by polyacrylamide gel electrophoresis and ultracentrifugal analysis. The molecular weight was approximately 17, 000 ( S 20 , w = 1.62) by the Archibald procedure, and the enzyme was found to be composed of approximately 126 amino acid residues. The isoelectric point was 5.2 (μ=0.1). The optimum pH for caseinolytic and N-acetyl-L-tyrosine ethyl ester hydrolyzing activities were about pH 8.0 and pH 7.5, respectively. The fin whale anionic enzyme was inhibited by DFP, like bovine pancreatic proteases, but not inhibited by N-tosyl-phenylalanine chloromethyl ketone. As far as the effects of bivalent cations, and natural trypsin inhibitors are concerned, no significant differences were found between fin whale and bovine anionic chymotrypsins. The substrate specificity was similar to that of bovine chymotrypsins B and α [EC 3.4.4.6 and 5].