Isolation of two chymotrypsins from grass carp.
Two chymotrypsins were purified from the hepatopancreas of grass carp (Ctenopharyngodon idellus) by chromatographies on phenyl-Sepharose and Q-Sepharose. The molecular weights of chymotrypsins I and II were 28 and 27 kDa, respectively. The two chymotrypsins showed similar susceptibility to inhibitions by phenylmethylsulfonyl fluoride and soybean trypsin inhibitor, but differed in their response to tosyl-L-phenylalanine chloromethyl ketone and aprotinin in which chymotrypsin I was more resistant. Chymotrypsin I was a less typical chymotrypsin and exhibited lower catalytic efficiency with the chymotrypsin-specific ester and amide substrates, when compared with chymotrypsin II. For both chymotrypsins, optimal activity was detected in the pH range 7.0-8.5.
Department of Biochemistry, Chinese University of Hong Kong, Shatin, N.T., Hong Kong. b348738@mailserv.cuhk.edu.hk
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Fong
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Chan
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Lau
D000818:Animals; D002347:Carps; D002918:Chymotrypsin / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D004064:Digestive System / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology
D007527:Isoenzymes; D015842:Serine Proteinase Inhibitors; D002918:Chymotrypsin