二价铜离子与聚胞嘧啶结合的研究。

Studies of bivalent copper ion binding to poly C.

作者信息

Sorokin V A, Blagoi Y P, Valeev V A, Antonova O A

出版信息

J Inorg Biochem. 1985 Jun;24(2):97-111. doi: 10.1016/0162-0134(85)80002-7.

Abstract

Ultraviolet differential spectra of single-stranded poly C, taken in the presence of Cu2+ ions, are studied at various ionic strengths and temperatures. Coordinational and conformational components of these spectra are obtained. The Cu2+ ion coordination site on the polynucleotide bases is found to be N(3) and possibly O(2). The direction of the poly C absorption band shift due to ion binding and conformational transitions is established. At low ionic strengths of the solution Cu2+ ions cause the helical parts of poly C to melt. At high ones the formation of double-stranded parts was observed in addition to the above effect. The calculated concentration dependences of ion-poly C bases association constants show that binding is cooperative at any ionic strength.

摘要

在不同离子强度和温度下，研究了在Cu2+离子存在下的单链聚C的紫外差分光谱。获得了这些光谱的配位和构象成分。发现多核苷酸碱基上的Cu2+离子配位位点为N(3)，可能还有O(2)。确定了由于离子结合和构象转变导致的聚C吸收带移动方向。在溶液的低离子强度下，Cu2+离子会导致聚C的螺旋部分熔化。在高离子强度下，除上述效应外，还观察到双链部分的形成。计算得到的离子与聚C碱基缔合常数的浓度依赖性表明，在任何离子强度下结合都是协同的。