Harlow R, Wells J R
J Cell Sci. 1975 Jul;18(2):217-25. doi: 10.1242/jcs.18.2.217.
Protease activity associated with avian erythroid chromatin has been studied by gel electrophoresis of histones. Histone degradation is minimal at neutral pH, but is readily detected when chromatin is incubated at pH 3, and is evident to a lesser extent at pH 9. As a result of the pH 3 activity, the f1 and f2 chistones are preferentially degraded when the histone complement is DNA-bound, but these histones are relatively resistant to attack when present as free histone. The pH 3 activity reported here has properties similar to those of neutral histone proteases from other tissues, except that it is not inhibited by bisulphite. Added exogenous proteins are not degraded. The activity of avian erythroid histone protease decreases as maturation of the cells proceeds. Since we have previously shown that turnover of DNA-bound f2c histone occurs in reticulocytes and histone synthesis is absent in erythrocytes, it is possible that the histone protease described here may be involved in f2c histone turnover.
通过组蛋白的凝胶电泳对与禽类红细胞染色质相关的蛋白酶活性进行了研究。在中性pH值下，组蛋白降解极少，但当染色质在pH 3下孵育时，很容易检测到降解，在pH 9时降解程度较小。由于pH 3时的活性，当组蛋白与DNA结合时，f1和f2组蛋白优先被降解，但当这些组蛋白以游离组蛋白形式存在时，它们相对不易受到攻击。这里报道的pH 3活性具有与其他组织中的中性组蛋白蛋白酶相似的特性，只是它不受亚硫酸氢盐抑制。添加的外源蛋白质不会被降解。随着细胞成熟，禽类红细胞组蛋白蛋白酶的活性降低。由于我们之前已经表明，DNA结合的f2c组蛋白在网织红细胞中发生周转，而红细胞中不存在组蛋白合成，因此这里描述的组蛋白蛋白酶可能参与f2c组蛋白的周转。
