表皮核酸酶：哺乳动物表皮核糖核酸酶的纯化与特性分析

Epidermal nucleases: purification and characterization of ribonuclease from mammalian epidermis.

作者信息

Melbye S W, Freedberg I M

出版信息

Biochim Biophys Acta. 1975 Apr 19;384(2):466-76. doi: 10.1016/0005-2744(75)90047-9.

Abstract

The major ribonuclease of adult guinea pig epidermis has been isolated and purfied over 1000-fold by a combination of ammonium sulfate fractionation, affinity and ion-exchange chromatography, and electrophoresis. The purified enzyme is free from phosphodiesterase and phosphatase activities. The ribonuclease is optimally active near neutrality in phosphate buffer, with a Km of 3mu g/ml toward [14-C]RNA from Erhlich ascites tumor cells. (here are no metal requirements for activity. The enzyme catalyzes the endonucleolytic hydrolysis of high molecular weight yeast RNA and it also hydrolyzes polycytidylic and polyuridylic acids, but not polyadenylic, polyguanylic, and polyinosinic acids. The apparent molecular weight of the active enzyme is 28 500.

摘要

成年豚鼠表皮的主要核糖核酸酶已通过硫酸铵分级分离、亲和色谱、离子交换色谱和电泳相结合的方法进行了分离和纯化，纯化倍数超过1000倍。纯化后的酶没有磷酸二酯酶和磷酸酶活性。该核糖核酸酶在磷酸盐缓冲液中接近中性时活性最佳，对艾氏腹水瘤细胞的[14-C]RNA的Km值为3μg/ml。该酶的活性不需要金属离子。它催化高分子量酵母RNA的内切核酸水解，也能水解聚胞苷酸和聚尿苷酸，但不能水解聚腺苷酸、聚鸟苷酸和聚肌苷酸。活性酶的表观分子量为28500。