Kurtovic I, Marshall S N, Simpson B K
Seafoods and Marine Extracts Group, Crop and Food Research Limited, P.O. Box 5114, Port Nelson, Nelson, New Zealand.
Comp Biochem Physiol B Biochem Mol Biol. 2006 Apr;143(4):432-40. doi: 10.1016/j.cbpb.2005.12.020. Epub 2006 Feb 2.
A trypsin fraction was isolated from the pyloric ceca of New Zealand farmed chinook salmon (Oncorhynchus tshawytscha) by ammonium sulfate fractionation, acetone precipitation and affinity chromatography. The chinook salmon enzyme hydrolyzed the trypsin-specific synthetic substrate benzoyl-DL-arginine-p-nitroanilide (DL-BAPNA), and was inhibited by the general serine protease inhibitor phenyl methyl sulfonyl fluoride (PMSF), and also by the specific trypsin inhibitors - soybean trypsin inhibitor (SBTI) and benzamidine. The enzyme was active over a broad pH range (from 7.5 to at least pH 10.0) at 25 degrees C and was stable from pH 4.0 to pH 10.0 when incubated at 20 degrees C, with a maximum at pH 8.0. The optimum temperature for the hydrolysis of DL-BAPNA by the chinook salmon enzyme was 60 degrees C, however, the enzyme was unstable at temperatures above 40 degrees C. The molecular mass of the chinook salmon trypsin was estimated as 28 kDa by SDS-PAGE.
通过硫酸铵分级分离、丙酮沉淀和亲和色谱法，从新西兰养殖的奇努克鲑（Oncorhynchus tshawytscha）幽门盲囊中分离出一种胰蛋白酶组分。奇努克鲑的这种酶能水解胰蛋白酶特异性合成底物苯甲酰-DL-精氨酸-对硝基苯胺（DL-BAPNA），并受到通用丝氨酸蛋白酶抑制剂苯甲基磺酰氟（PMSF）以及特异性胰蛋白酶抑制剂——大豆胰蛋白酶抑制剂（SBTI）和苯甲脒的抑制。该酶在25℃时在较宽的pH范围内（从7.5到至少pH 10.0）具有活性，在20℃孵育时，在pH 4.0至pH 10.0范围内稳定，在pH 8.0时活性最高。奇努克鲑酶水解DL-BAPNA的最适温度为60℃，然而，该酶在40℃以上的温度下不稳定。通过SDS-PAGE估计奇努克鲑胰蛋白酶的分子量为28 kDa。
