THE SOLUTION ENVIRONMENT OF NUCLEIC ACIDS

解决方案环境的本质影响，以及最近的 离子分布特别是在核酸生物化学上的分布是广泛的 已确认。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 核酸-蛋白质复合体中的过程。然而，详细的 对这种环境的微观描述仅限于 现在时。因此，对离子分布的理论研究 将对多核苷酸溶液进行收费。第一 这项研究的目的是在分子水平上描述 简单盐离子在延伸区的空间分布 多核苷酸链及其分布相关性分析 对小离子尺寸和电荷，以及聚电解质电荷密度的影响。 将在#年对简单盐混合物进行相应的研究。 为了开发一幅相应的详细的竞争离子图 协会。这样的研究将提供更详细的图景 多核苷酸的离子环境比目前可从 实验结构研究，例如使用核磁共振技术的研究。 此外，结果将提供对LESS的可靠性的测试 详细的，但也更容易评估的理论描述。这个 研究将使用最先进的统计机械方法， 包括积分方程式和计算机模拟技术；每一个 这是研究简单电解液的一种行之有效的方法。 最初的多核苷酸模型，即均匀带电棒的模型，已经被 早期的工作表明，这对解释实验有价值 数据。对模型进行了逻辑上的改进，以包括更现实的 聚电解质的电荷分布，聚合物的柔韧性，以及准确的 将继续进行溶剂效应的处理。结果将会阐明 构成分子溶液结构的基本方面 多核苷酸构象及其与核酸的相互作用 酸和多肽，并将为更长时间提供必要的元素 术语继续完善此类相互作用的量化模型。

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.