马铃薯蛋白酶A抑制剂的纯化与性质

Purification and Characters of Protease A Inhibitor from Potato

采用硫酸铵沉淀、Sephadex G-50和CM柱层析，从马铃薯汁中纯化蛋白酶A（protease A，PrA）抑制剂，并对其部分性质进行研究。蛋白酶A抑制剂为单亚基，相对分子质量为16．71kDa。热稳定性良好，抑制最佳pH范围为5—5．5，最佳反应时间为1．5h，对PrA抑制类型为竞争和非竞争性混合抑制作用。

Protease A inhibitor was purified from potato juice by ammonium sulfate, Sephadex G-50 filtration and CM chromatography. Parts of its characters were analyzed. The results showed that the inhibitor had one subunit, and its relative molecular quality was 16.71 kDa. The inhibitor had a good stability, the best pH limit of inhibition was 5-5.5, the best reaction time was 1.5 h, and the inhibition type was the complex of non-competitiveand competitive inhibition.