Okitani A, Matsumoto T, Kitamura Y, Kato H
Biochim Biophys Acta. 1981 Dec 15;662(2):202-9. doi: 10.1016/0005-2744(81)90031-0.
Cathepsin D (EC 3.4.23.4) was purified from rabbit skeletal muscle using acetone-dried muscle powder as starting material. After the acetone-dried powder was extracted with 0.2 mM ATP, the extract was fractionated with acetone an subjected to DEAE-Sephadex A-50 and Sephadex G-100 column chromatography. Rechromatography on a Sephadex G-100 column resulted in a purified preparation. SDS-polyacrylamide gel electrophoresis of the purified enzyme showed one major band of 42,000 daltons and some bands of contaminants. Since gel filtration also indicated a value of 42,000 daltons for the enzyme, it was concluded that muscle cathepsin D has no subunit structure. The enzyme acted optimally towards myofibrils around pH3, resulting in the degradation of the myosin heavy chain and production of a 30,000-dalton component.
组织蛋白酶D（EC 3.4.23.4）以丙酮干燥的肌肉粉末为起始原料，从兔骨骼肌中纯化得到。用0.2 mM ATP提取丙酮干燥粉末后，提取物用丙酮分级分离，然后进行DEAE-葡聚糖A-50和葡聚糖G-100柱色谱。在葡聚糖G-100柱上再进行色谱分离得到纯化制剂。纯化酶的SDS-聚丙烯酰胺凝胶电泳显示一条主要的42,000道尔顿条带和一些杂质条带。由于凝胶过滤也表明该酶的分子量为42,000道尔顿，因此得出结论，肌肉组织蛋白酶D没有亚基结构。该酶在pH3左右对肌原纤维的作用最佳，导致肌球蛋白重链降解并产生一个30,000道尔顿的组分。
