COMPARISON OF TRYPSIN AND CHYMOTRYPSIN FROM THE VISCERA OF ANCHOVY, ENGRAULIS-JAPONICA

The molecular weights of trypsin and chymotrypsin purified from anchov y viscera were estimated to be 25.6 and 26.1 Kda, respectively, by SDS -PAGE, Both enzymes had their maximal activity at pH 9.0 and 45 degree s C for casein and at pH 8.0 and 45 degrees C for synthetic substrates . Trypsin hydrolyzed at the position of Arg(22) and Lys(29), and chymo trypsin did at the position of Phe(1), Tyr(16), Phe(24), Phe(25) and T yr(26) of insulin beta-chain. The K-m' and k(cat) of trypsin were 50 m u M and 1.84 mu M min(-1) toward N-benzoyl-L-arginine-p-nitroanilide ( BAPNA) and those of chymotrypsin were 89 mu M and 10.0 mu M(-1)min(-1) toward N-succinyl-(Ala)(2)-Pro-Phe-p-nitroanilide. The activation ene rgy of trypsin and chymotrypsin were estimated to be 14 Kcal/mol towar d N-benzoyl-L-arginine-p-nitroanilide and 6.5 Kcal/mol toward benzoyl- L-tyrosine ethyl ester.