Properties of Trypsin from the Pyloric Ceca of Atlantic Cod (Gadus morhua) |
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| Authors: | B.K. SIMPSON M.V. SIMPSON N.F. Haard |
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| Affiliation: | Authors B.K. Simpson and M.V. Simpson are with the Dept. of Food Science &Agricultural Chemistry, Macdonald College of McGill Univ., 21,111 Lakeshore Road, Ste. Anne de Bellevue, Quebec, Canada, H9X 1C0.;Author Haard is with the Dept. of Food Science &Technology, Institute of Marine Resources, Univ. of California, Davis, CA |
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| Abstract: | Trypsin (EC 3.4.21.4) was isolated from the pyloric ceca of Atlantic cod and purified to homogeneity by affinity chromatography. The enzyme catalyzed the hydrolysis of benzoyl arginine p-nitroanilide (BAPA, pH 8.2 and 25°C) such that Vmax was 250 BAPA units per micromole trypsin and Km was 1.48 mM. For the hydrolysis of tosyl arginine methyl ester (TAME, pH 8.1 and 25°C), Vmax was 18.2 × 103 TAME units/micromole trypsin, and Km 0.22 mM. The pH and temperature optima with BAPA substrate were 7.5 and 40°C, respectively. Atlantic cod trypsin was most active and stable at alkaline pH. The enzyme was heat labile, losing more than 50% of its activity after incubation at 50°C for 30 min. Amino acid analysis of Atlantic cod trypsin revealed that the enzyme was rich in residues such as serine, glycine, glutamate and aspartate, but poor in basic amino acid residues compared to trypsins from warm blooded animals. |
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