Abstract: A trypsin inhibitor named TCTI was isolated from the rhizomes of Tinospora crispa (Menispermaceae) by trichloroacetic acid precipitation, salting out, chromatography on trypsin-Sepharose 4B and SHyperTM10 FPLC column, preparative PAGE and electroelution. The relative molecular weight of TCTI was 10.0kD by TSDS-PAGE. The inhibition of trypsin by the TCTI was competitive, with a Ki value of 2.08×10-7mol/L(BANPA as substrate) and the mole ratio was about 1:3.5. TCTI was heat- tolerating. When heated up to 100C for 60 min, it still had 93% residual activities. On the other hand, TCTI can be easily crystalized under lower temperature.

Key words: Tinospora crispa

摘要： 采用亲和层析及电泳制备等方法,从防已科植物波叶青牛胆(Tinospora crispa)根茎中分离到一种胰蛋白酶抑制剂TCTI.对其性质研究表明:TCTI的相对分子量约为10.0kD,对牛胰蛋白酶的抑制常数Ki为2.08×10-7mol/L(BAPNA为底物时),摩尔抑制比为1∶3.5,是一种抑制活力很强的竞争性抑制剂.TCTI具有很高的耐热性,在100℃加热60min,仍保持93%的抑制活力.另外,TCTI在低温容易结晶.

关键词: 波叶青牛胆, 胰蛋白酶抑制剂, 分离和纯化