Sawicki G, Warwas M
Department of Pharmaceutical Biochemistry, Medical Academy, Wroclaw, Poland.
Acta Biochim Pol. 1989;36(3-4):343-51.
Cathepsin H was isolated from human placenta by autolysis, acetone fractionation, and chromatography on DEAE-cellulose, Sephadex G-75, hydroxyapatite and concanavalin A-Sepharose. The enzyme gave on SDS-polyacrylamide gel electrophoresis two bands of Mr 25,500 and 28,500. Two active forms of the enzyme, with pI of 6.0 and 6.45, were obtained by isoelectric focusing. The enzyme is stable over the pH range 5-7.5, whereas it becomes inactive on heating to 50 degrees C. Cathepsin H of human placenta, like the enzyme from other sources, hydrolyses protein and naphthylamide substrates, showing within the latter group the strongest preference towards arginine-beta-naphthylamide (pH optimum 6.8). The enzyme is inhibited by the known inhibitors of cysteine proteases and by placental cystatins.
组织蛋白酶H是通过自溶、丙酮分级分离以及在DEAE-纤维素、葡聚糖凝胶G-75、羟基磷灰石和伴刀豆球蛋白A-琼脂糖上进行色谱分离从人胎盘中分离出来的。该酶在SDS-聚丙烯酰胺凝胶电泳上呈现出两条分子量分别为25,500和28,500的条带。通过等电聚焦获得了该酶的两种活性形式，其pI分别为6.0和6.45。该酶在pH 5 - 7.5范围内稳定，而加热至50℃时会失活。人胎盘组织蛋白酶H与其他来源的该酶一样，能水解蛋白质和萘基酰胺底物，在后者中对精氨酸-β-萘基酰胺表现出最强的偏好（最适pH 6.8）。该酶受到已知的半胱氨酸蛋白酶抑制剂和胎盘胱抑素的抑制。
