大豆胰蛋白酶抑制因子的分离纯化

Extraction and Purification of Soybean Trypsin Inhibitor

以脱脂豆粉为原料,经pH7.6磷酸溶液抽提、65℃热变性、硫酸铵分步沉淀等提取技术制备粗提液,之后再经过DEAE-52离子交换、亲和层析和葡聚糖凝胶过滤等纯化技术研究大豆胰蛋白酶抑制因子的分离纯化方法。结果表明,从脱脂豆粉中分离纯化的大豆胰蛋白酶抑制因子的比活力高达4 600 U.mg-1,提纯倍数为73.85。纯化的大豆胰蛋白酶抑制因子经SDS-PAGE电泳分析,呈现2条谱带,分子量分别为21.92和20.04 kDa,这2种蛋白均为大豆胰蛋白酶抑制因子。该法操作简便,分离纯化效果好,对大豆胰蛋白酶抑制因子的研究与生产有重要的参考价值。

In this paper, soybean meal was used as raw material. The crude extract of the soybean trypsin inhibitor（STI） was obtained by the extraction of phosphoric acid buffer（ pH7.6 ）, thermal denaturation（ 65℃ ）and ammonium sulfate precipitati- on. Then this extract was purified by DE-52 ion exchange, affinity chromatography and sephadex G-75 gel filtration. The results showed that the specific activity of soybean trypsin inhibitor reached 4 600 U·mg- 1 and purification factor of 73.85 was ob- tained. The purified STI gave two protein bands in SDS-PAGE electrophoresis. Its molecular weights were estimated to be 21.92 and 20.04 kDa. Due to the ease and simpleness of the procedure and high efficiency, the method has an important refer- ence value to research and production of soybean trypsin inhibitor.