章鱼内脏胰蛋白酶抑制剂的分离纯化与性质研究

通过热处理、硫酸铵盐析、膜超滤及SP-Sepharose离子交换层析,从章鱼内脏中纯化得到一种胰蛋白酶抑制剂（Octopus Trypsin Inhibitor,OTI）.Tricine-SDS-PAGE电泳结果显示,OTI的分子质量约为6500 u.性质分析结果表明：OTI在pH=1.0～11.0缓冲液中孵育30 min,抑制活性稳定;在100℃下加热1 h、2 h后仍分别具有90%和65%的抑制活性,具有良好的pH值稳定性和热稳定性;OTI能够显著抑制胰蛋白酶的活性,对胰凝乳蛋白酶、胃蛋白酶和木瓜蛋白酶几乎无抑制活性;OTI能够有效抑制蓝圆鲹肌肉中肌原纤维结合型丝氨酸蛋白酶（MBSP）引起的肌球蛋白降解.

Purification and Characterization of a Trypsin Inhibitor from the Viscera of Octopus （ Octopus fangsiao）

An octopus trypsin inhibitor （OTI） was purified from the viscera of octopus by processes in-cluding heat treatment, ammonium sulfate fractionation, uhrafiltration and SP - Sepharose ion exchange chro-matography. The purified OTI was in homogeneity with a molecular mass of approximately 6500 u on Tricine-SDS -PAGE. OTI maintained high activity at pH range of 1.0 ~ 11.0. More than 90% and 65% of its initial inhibitory activity remained after incubation at 100 ~C for 1 h and 2 h, respectively, suggesting its high stability under high temperature. OTI was specifically active against trypsin, while revealed no inhib-itory activity to pepsin, chymotrypsin and papain. Furthermore, OTI was effective in suppressing the degra-dation of myofibrillar proteins in the skeletal muscle of blue scad （ Decapterus maruadsi） caused by an endog-enous myofibril-bound serine proteinase （MBSP）.