牛精核糖核酸酶对脱氧核糖核酸和聚[d(A-T).d(A-T)]的螺旋解稳定作用

Helix-destabilization of deoxyribonucleic acid and poly[d(A-T).d(A-T)] by bovine seminal ribonuclease.

作者信息

Pandit M W, Ramakrishna T

出版信息

Biochim Biophys Acta. 1986 May 27;867(1-2):1-8. doi: 10.1016/0167-4781(86)90022-9.

Abstract

A ribonuclease isolated earlier from bovine seminal plasma by DNA-affinity chromatography (Ramakrishnamurti, T. and Pandit, M.W. (1983) J. Chromatogr. 260, 216-222) has now been shown by thermal denaturation studies to destabilize the double-helical structure of DNA and poly[d(A-T).d(A-T)]. Thermal denaturation profiles of DNA in the presence of the protein are much more complicated due to the denaturation of protein itself in the temperature range over which DNA predominantly melts. The protein shows relatively stronger affinity towards denatured DNA as compared to native DNA. The action of micrococcal nuclease on DNA and its complexes with ribonuclease A and bovine seminal ribonuclease indicates that both of these proteins destabilize the double-helical structure of native DNA and thereby render the DNA more sensitive to the micrococcal nuclease.

摘要

先前通过DNA亲和色谱法从牛精浆中分离出的一种核糖核酸酶（Ramakrishnamurti, T. 和 Pandit, M.W. (1983) J. Chromatogr. 260, 216 - 222），现在通过热变性研究表明它会使DNA和聚[d(A - T).d(A - T)]的双螺旋结构不稳定。由于在DNA主要发生熔解的温度范围内蛋白质自身会变性，所以在该蛋白质存在时DNA的热变性图谱要复杂得多。与天然DNA相比，该蛋白质对变性DNA表现出相对更强的亲和力。微球菌核酸酶对DNA及其与核糖核酸酶A和牛精浆核糖核酸酶的复合物的作用表明，这两种蛋白质都会使天然DNA的双螺旋结构不稳定，从而使DNA对微球菌核酸酶更敏感。