pH值和温度变化诱导的聚胞苷酸的结构转变：溶液态和薄膜态的振动圆二色性研究

Structural transitions in polyribocytidylic acid induced by changes in pH and temperature: vibrational circular dichroism study in solution and film states.

作者信息

Petrovic Ana G, Polavarapu Prasad L

机构信息

Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA.

出版信息

J Phys Chem B. 2006 Nov 16;110(45):22826-33. doi: 10.1021/jp063221l.

DOI:10.1021/jp063221l

PMID:17092034

Abstract

Changes in vibrational absorption and vibrational circular dichroism (VCD) spectra of polyribocytidylic acid (polyC) in buffered D(2)O solution as a function of pH and temperature are reported. Analysis of these spectral data led us to establish the absorption band at approximately 1693 cm(-1) and associated negative VCD couplet as diagnostic markers of the double-helical form of polyC. An alternate interpretation suggesting quadruplex formation for polyC is also discussed. In addition to the solution state spectral data, pH-dependent absorption and VCD spectra for polyC films derived from dilute H(2)O solutions are also presented. The pH-dependent changes in the absorption and VCD spectra of polyC films are found to be similar to those observed for polyC in solution.

摘要

报道了在缓冲的重水（D₂O）溶液中，聚核糖胞苷酸（polyC）的振动吸收和振动圆二色性（VCD）光谱随pH值和温度的变化情况。对这些光谱数据的分析使我们确定了在约1693 cm⁻¹处的吸收带以及相关的负VCD偶合峰，作为polyC双螺旋形式的诊断标记。还讨论了一种认为polyC形成四链体的另一种解释。除了溶液状态的光谱数据外，还给出了由稀水溶液制备的polyC薄膜的pH依赖性吸收光谱和VCD光谱。发现polyC薄膜的吸收光谱和VCD光谱随pH值的变化与溶液中polyC的情况相似。