中文摘要：

为了获得具有较高活力的海参肠组织蛋白酶B，研究了其粗酶的提取条件。以Z-Arg—Arg—MCA为特异性底物，采用荧光光度法测定了酶活力。对提取海参肠组织蛋白酶B的浸提缓冲液、浸提时间和硫酸铵饱和度进行优化。结果表明，采用含5mmol／LL-半胱氨酸、1mmol／LEDTA、0．2％Triton X-100的50mmol／LpH5．0的NaAc-HAc缓冲液浸提7h后，选择80％饱和度的硫酸铵进行沉淀，能够有效地从海参肠道中提取组织蛋白酶B；同时研究了巯基保护剂对酶活力的影响。结果表明，巯基保护剂可提高酶的活力，这符合组织蛋白酶B结构中含有巯基的特性。在提取粗酶的过程中，添加巯基保护剂可有效地保证酶活力。

英文摘要：

To obtain high activity of cathepsin B from the gut of sea cucumber, the extraction condition was optimized, in which the fluorophotometry was applied to enzyme assay and Z-Arg-Arg-MCA was used as substrate. The better results were obtained by precipitation with 80% saturated （NH4）2SO4 after extraction for 7 h with NaAc-HAe buffer （pH 5.0） containing 5 mmol/L L-Cys, 1 mmol/L EDTA and 0.2% Triton X-100. The thiol-activating agents could enhance the enzyme activity, suggesting that the purified protease has the characteristic of eathepsin B containing SH group（s）.