回转半径的标度律及其对疏水性的依赖性
Scaling Law for Radius of Gyration and Its Dependence on Hydrophobicity
摘要：
生物分子几何量和动力学量的标度律是一个有趣的课题。根据Flory理论，发现均聚物链长与回转半径之间存在幂律关系，其指数在良溶剂时为3/5，在不良溶剂时为1/3。对于生理条件下的蛋白质，在两者之间的溶剂条件下，得到了指数为~2/5的幂律。本文提出了一个统一的公式，以涵盖上述所有情况。结果表明，在一定的溶剂条件下，标度指数一般与链的分形维数相关。当我们的公式应用于蛋白质，分形维数被发现依赖于它的疏水性。通过把一个物理过程的氨基酸突变链的疏水性变化，一个等效的化学过程，通过添加极性或非极性分子的溶剂的极性变化，我们成功地剥夺了这种关系，合理的协议统计数据。这将有助于蛋白质结构的预测。我们的研究结果表明，蛋白质可以共享相同的基本原则，与均聚物，尽管它的特异性作为一个杂聚物。
英文摘要：
Scaling law for geometrical and dynamical quantities of biological molecules is an interesting topic. According to Flory's theory, a power law between radius of gyration and the length of homopolymer chain is found, with exponent 3/5 for good solvent and 1/3 for poor solvent. For protein in physiological condition, a solvent condition in between, a power law with exponent ~2/5 is obtained. In this paper, we present a unified formula to cover all above cases. It shows that the scaling exponents are generally correlated with fractal dimension of a chain under certain solvent condition. While applying our formula to protein, the fractal dimension is found to depend on its hydrophobicity. By turning a physical process-varying hydrophobicity of a chain by amino acid mutation, to an equivalent chemical process-varying polarity of solvent by adding polar or nonpolar molecules, we successfully deprive this relation, with reasonable agreement to statistical data. And it will be helpful for protein structure prediction. Our results indicate that the protein may share the same basic principle with homopolymer, despite its specificity as a heteropolymer.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
