Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland 20892, United States.
Department of Chemistry and Biochemistry, Worcester Polytechnic Institute , Worcester, Massachusetts 01609, United States.
J Phys Chem B. 2018 Feb 1;122(4):1484-1494. doi: 10.1021/acs.jpcb.7b10730. Epub 2018 Jan 22.
All-atom molecular dynamics simulations combined with graph-theoretic analysis reveal that clustering of monomethyl phosphate dianion (MMP) is strongly influenced by the types and combinations of cations in the aqueous solution. Although Ca promotes the formation of stable and large MMP clusters, K alone does not. Nonetheless, clusters are larger and their link lifetimes are longer in mixtures of K and Ca. This "synergistic" effect depends sensitively on the Lennard-Jones interaction parameters between Ca and the phosphorus oxygen and correlates with the hydration of the clusters. The pronounced MMP clustering effect of Ca in the presence of K is confirmed by Fourier transform infrared spectroscopy. The characterization of the cation-dependent clustering of MMP provides a starting point for understanding cation-dependent clustering of phosphoinositides in cell membranes.
全原子分子动力学模拟结合图论分析表明，单甲基磷酸二阴离子（MMP）的聚集强烈受到水溶液中阳离子类型和组合的影响。尽管 Ca 促进了稳定且大的 MMP 簇的形成，但 K 单独不能。然而，在 K 和 Ca 的混合物中，簇更大，它们的链接寿命更长。这种“协同”效应对 Ca 与磷氧之间的 Lennard-Jones 相互作用参数敏感，并与簇的水合作用相关。傅里叶变换红外光谱证实了 Ca 在 K 存在下对 MMP 强烈的聚类效应。MMP 阳离子依赖性聚集的特征为理解细胞膜中磷酸肌醇的阳离子依赖性聚集提供了起点。
