THE SOLUTION ENVIRONMENT OF NUCLEIC ACIDS

溶液环境的本质影响，以及 特别是离子分布对核酸生物化学的影响， 承认。 重要的例子包括契约的形成 细胞染色质的多核苷酸结构及其结合和识别 在核酸-蛋白质复合物中的过程。 然而，详细 这种环境的微观描述只是初步的， 礼物 因此，离子分布的理论研究 将在多核苷酸溶液中进行充电。 第一 本研究的目的是在分子水平上描述 简单盐离子在扩展的 多核苷酸链和这种分布的依赖性分析 小的离子尺寸和电荷，以及小的电荷密度。 用简单的盐混合物进行相应的研究将在 为了开发一个相应的竞争性离子的详细图片 协会 这些研究将提供一个更详细的图片， 多核苷酸的离子环境比目前可从 实验结构研究，例如使用NMR技术的那些。 此外，结果将提供测试的可靠性少 详细的，但也更容易评估，理论描述。 的 研究将采用最先进的统计力学方法， 包括积分方程和计算机模拟技术; 这是研究简单电解质溶液的经证实的方法。 最初的多核苷酸模型，即均匀带电的棒，已经被 早期的工作表明，对于解释实验结果是有价值的。 数据 对模型进行了逻辑改进， 电荷分布、聚合物柔性和精确的 将继续进行溶剂效应的处理。 结果将阐明 分子溶液结构的基本方面， 多核苷酸构象和多核苷酸与核酸的相互作用 酸和多肽，并将提供必要的元素， 长期不断完善这种相互作用的定量模型。

The essential influence of the solution environment, and the proximate ionic distribution in particular, on nucleic acid biochemistry is widely acknowledged. Important examples include the formation of the compact polynucleotide structures of cellular chromatin and binding and recognition processes in nucleic acid-protein complexes. However, the detailed microscopic description of this environment is only rudimentary at present. Therefore, theoretical studies of the distribution of ionic charge in polynucleotide solutions will be carried out. The first objective of this research is the description, at the molecular level, of the spatial distribution of simple salt ions around an extended polynucleotide chain and an analysis of the dependence of this distribution on small ion size and charge, as well as polyelectrolyte charge density. Corresponding studies with simple salt mixtures will be carried out in order to develop a correspondingly detailed picture of competitive ionic association. Such studies will provide a much more detailed picture of the ionic environment of polynucleotides than is presently available from experimental structural studies, such as those using NMR techniques. Further, the results will provide tests of the reliability of less detailed, but also more readily evaluated, theoretical descriptions. The studies will employ state-of-the-art statistical mechanical methods, including integral equation and computer simulation techniques; each of these is a proven approach to the study of simple electrolyte solutions. The initial polynucleotide model, that of a uniformly charged rod, has been shown by earlier work to be valuable for the interpretation of experimental data. Logical refinements of the model to include a more realistic polyelectrolyte charge distribution, polymer flexibility, and an accurate treatment of solvent effects will be pursued. The results will elucidate fundamental aspects of the molecular solution structure which underlie polynucleotide conformation and polynucleotide interactions with nucleic acids and polypeptides and will provide necessary elements for the longer term continued refinement of quantitative models for such interactions.