CATHEPSIN-D - PURIFICATION OF ISOENZYMES FROM HUMAN AND CHICKEN LIVER
CATHEPSIN-D - PURIFICATION OF ISOENZYMES FROM HUMAN AND CHICKEN LIVER
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DOI：
10.1042/bj1170601
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发表时间：
1970-01-01
影响因子：
4.1
通讯作者：
BARRETT, AJ
中科院分区：
文献类型：
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作者：
BARRETT, AJ
1.对组织蛋白酶D的Barrett（1967）测定法进行了轻微修改。2.用自溶、丙酮分级、离子交换层析和等电聚焦等方法从人肝和鸡肝中纯化了该酶。3.在等电聚焦步骤中分辨了组织蛋白酶D的几种同工酶，并区分了每个物种的三种主要形式，α，β和γ。4.改进的聚丙烯酰胺凝胶等电聚焦分析方法表明，各种β和γ同工酶的均一性很高，这是由它们恒定的高比活性所支持的。5.在Sephadex G-100的校准柱中的同工酶的凝胶过滤显示，每个具有45000的分子量。6.人组织蛋白酶D的最适pH为3.5，鸡酶的最适pH为3.0，血红蛋白用作底物。在每个物种中，三种同工酶具有相同的pH依赖曲线。7.纯化的组织蛋白酶D样品对酸变性白蛋白几乎没有作用。
1. The Barrett (1967) assay for cathepsin D was slightly modified. 2. The enzyme was purified from liver of man and chicken by a procedure involving autolysis, acetone fractionation, ion-exchange chromatography and isoelectric focusing. 3. Several isoenzymes of cathepsin D were resolved in the isoelectric-focusing step, and three major forms, α,β and γ, were distinguished for each species. 4. A modified analytical method of isoelectric focusing in polyacrylamide gel indicated a high degree of homogeneity of the purified β and γ isoenzymes from each species, and this was supported by their constant high specific activities. 5. Gel filtration of the isoenzymes in a calibrated column of Sephadex G-100 showed that each had a molecular weight of 45000. 6. Human cathepsin D had a pH optimum of 3.5, and that of chicken enzyme was 3.0, haemoglobin being used as substrate. In each species, the three isoenzymes have the same pH-dependence curve. 7. The purified cathepsin D samples showed very little action on acid-denatured albumin.