Chun Byung-Soo, Kishimura Hideki, Nalinanon Sitthipong, Klomklao Sappasith, Benjakul Soottawat
Department of Food Science and Technology, Pukyong National University, Busan 608-737, Republic of Korea.
J Amino Acids. 2011;2011:728082. doi: 10.4061/2011/728082. Epub 2011 Jul 13.
Viscera of mackerel (Scomber sp.) were defatted by supercritical carbon dioxide (SCO(2)) treatment. Trypsin (SC-T) was then extracted from the defatted powder and purified by a series of chromatographies including Sephacryl S-200 and Sephadex G-50. The purified SC-T was nearly homogeneous on SDS-PAGE, and its molecular weight was estimated as approximately 24,000 Da. N-terminal twenty amino acids sequence of SC-T was IVGGYECTAHSQPHQVSLNS. The specific trypsin inhibitors, soybean trypsin inhibitor and TLCK, strongly inhibited the activities of SC-T. The pH and temperature optimums of SC-T were at around pH 8.0 and 60°C, respectively, using N(α)-p-tosyl-L-arginine methyl ester as a substrate. The SC-T was unstable below pH 5.0 and above 40°C, and it was stabilized by calcium ion. These enzymatic characteristics of SC-T were the same as those of other fish trypsins, especially spotted mackerel (S. borealis) trypsin, purified from viscera defatted by acetone. Therefore, we concluded that the SCO(2) defatting process is useful as a substitute for organic solvent defatting process.
用超临界二氧化碳（SCO₂）处理鲭鱼（Scomber sp.）的内脏进行脱脂。然后从脱脂粉末中提取胰蛋白酶（SC-T），并通过包括Sephacryl S-200和Sephadex G-50在内的一系列色谱法进行纯化。纯化后的SC-T在SDS-PAGE上几乎呈单一状态，其分子量估计约为24,000 Da。SC-T的N端二十个氨基酸序列为IVGGYECTAHSQPHQVSLNS。特异性胰蛋白酶抑制剂，大豆胰蛋白酶抑制剂和TLCK，强烈抑制SC-T的活性。以N（α）-对甲苯磺酰-L-精氨酸甲酯为底物时，SC-T的最适pH和温度分别约为pH 8.0和60°C。SC-T在pH 5.0以下和40°C以上不稳定，并且钙离子可使其稳定。SC-T的这些酶学特性与其他鱼胰蛋白酶相同，特别是从用丙酮脱脂的内脏中纯化的斑点鲭鱼（S. borealis）胰蛋白酶。因此，我们得出结论，SCO₂脱脂工艺可作为有机溶剂脱脂工艺的替代品。
