Kominami E, Wakamatsu N, Katunuma N
Acta Biol Med Ger. 1982;41(1):69-74.
A thiol proteinase inhibitor was purified from rat liver by a rapid procedure involving heat treatment of the post-lysosomal fraction, affinity chromatography on papain-Sepharose 4B and Sephadex G-75. The purified inhibitor appeared homogeneous on sodium dodecyl sulfate electrophoresis. The inhibitor had a molecular weight of about 11000 and consists of three forms (pI 4.9, 5.2 and 5.6). The preparation inhibited thiol proteinases but not serine proteinase or aspartate proteinase. Kinetic studies of inhibition of papain by the inhibitor indicate that the inhibition was noncompetitive and pseudo-irreversible. Subcellular fractionations of rat liver indicate that most of all the inhibitor is localized in the cytosol fraction. The physiological role of the inhibitor is discussed.
通过一种快速方法从大鼠肝脏中纯化出一种巯基蛋白酶抑制剂，该方法包括对溶酶体后组分进行热处理、在木瓜蛋白酶-琼脂糖4B和葡聚糖凝胶G-75上进行亲和层析。纯化后的抑制剂在十二烷基硫酸钠电泳中呈现均一性。该抑制剂的分子量约为11000，由三种形式组成（等电点分别为4.9、5.2和5.6）。该制剂可抑制巯基蛋白酶，但不抑制丝氨酸蛋白酶或天冬氨酸蛋白酶。抑制剂对木瓜蛋白酶抑制作用的动力学研究表明，这种抑制是非竞争性的且近乎不可逆的。大鼠肝脏的亚细胞分级分离表明，所有抑制剂中的大部分定位于胞质溶胶组分中。文中讨论了该抑制剂的生理作用。
