Polarizable Force Field for Proteins and Lipids

蛋白质和脂质的极化力场

• 批准号: 10298612
• 负责人: BENOIT ROUX
• 金额: $ 39.77万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10298612
• 关键词: Attention; Binding; Biological; Biological Models; Carbohydrates; Cell Membrane Permeability; Charge; Complex; Data; Development; Divalent Cations; Electric Conductivity; Electrostatics; Energy Transfer; Free Energy; Funding; Hydrocarbons; Immunoglobulin Constant Region; Ions; Lateral; Length; Lipids; Measurement; Mechanics; Membrane; Membrane Lipids; Microscopic; Modeling; Molecular; Monovalent Cations; Nature; Nucleic Acids; Osmotic Pressure; Philosophy; Phosphatidylinositol 4,5-Diphosphate; Phospholipids; Play; Potential Energy; Process; Production; Property; Proteins; Relaxation; Role; Sampling; Sodium Chloride; Structure; Sum; System; Technology; Time; Vacuum; Validation; Water; base; biological systems; design; driving force; improved; infrared spectroscopy; membrane model; molecular dynamics; quantum; response; screening; simulation; small molecule; solute; theories; two-dimensional; voltage sensitive dye; zeta potential

PROJECT SUMMARY Molecular dynamics (MD) simulations based on atomistic models play an increasingly important role in understanding the fundamental physical forces driving the structure and dynamics of biological membranes. However, to have meaningful simulations, accurate and empirical force fields (FFs) are necessary. Although nonpolarizable additive FFs are useful approximations, polarizable models of biological membranes are needed to account for their complex molecular nature. The present efforts to develop and optimize a polarizable FF for lipids will allow fundamental simulation studies of a broad range of processes associated with biological membranes. During the last funding period we made significant progress with the development of a polarizable FF based on the classical Drude oscillator model. The Drude FF has been implemented in CHARMM, NAMD, ChemShell QM/MM, GROMACS and the OpenMM GPU suite, allowing for unbiased simulations on the microsecond time scale as well as simulations exploiting a range of enhanced sampling technologies. We can already model water, ions, proteins, nucleic acids, carbohydrates, and a few neutral phospholipids. At this point there is a critical need to expand the type of phospholipids covered by the Drude FF to enable the modeling of a wider range of biological membrane systems, as over one third of all MD simulations of biological systems involve bilayer membranes. Polarizable models of biological membranes are necessary to account for their complex molecular nature, where a variety of strong electrostatic factors compete with one another over microscopic length-scales. The plan is to perform a global optimization and validation of the Drude FF for lipids using structural, dynamical, and mechanical information as physical target membrane data for the optimization, and improve the treatment of nonbonded interactions via a lattice sum of the long-range van der Waals dispersion (LJ-PME), and simultaneously extend the Drude FF to cover charged lipids with a special attention to the strong interactions of ions with the polar headgroup (Aim 1). We will then use the refined Drude FF to study fundamental aspects biomembrane electrostatics and elucidate the contribution of electronic polarization on the fundamental electrostatics features of biological membranes (Aim 2) with a study of the classical concept of ζ-potential and the properties of membrane-bound voltage-sensitive dyes with polarizable models for the ground and excited state. Lastly, we will develop accurate polarizable models of phosphatidylinositol-4,5-bisphosphate (PIP2), with a special attention to the interactions with monovalent and divalent cations to study ion-induced domain formation and lateral clustering of PIP2 (Aim 3).

项目摘要 基于原子模型的分子动力学（MD）模拟在 了解驱动生物膜的结构和动力学的基本物理力。 但是，要进行有意义的模拟，必须进行准确和经验的力场（FFS）。虽然 不可极化的加性FF是有用的近似值，生物膜的两极分化模型是 需要考虑其复杂的分子本质。目前为开发和优化的努力 脂质的两极分化FF将允许对相关的广泛过程进行基础模拟研究 具有生物学机制。在最后的资金期间，我们在开发方面取得了重大进展 基于经典Drude振荡器模型的可极化FF的。 Drude FF已在 Charmm，NAMD，Chemshell QM/mm，gromacs和OpenMM GPU套件，允许无偏见 微秒时间尺度的模拟以及开发一系列增强采样范围的模拟 技术。我们已经可以建模水，离子，蛋白质，核酸，碳氢化物和一些中性 磷脂。在这一点 FF可以实现各种生物膜系统的建模，因为超过三分之一的MD 生物系统的仿真涉及双层膜。生物膜的两极分化模型是 考虑到各种强静电因子的复杂分子性质所必需的必要 在显微镜长度尺度上相互竞争。该计划是执行全球优化，并且 使用结构，动态和机械信息作为物理目标验证DRUDE FF对脂质的脂质验证 膜数据进行优化，并通过晶格总和改善了非键相互作用的处理 远程范德华分散剂（LJ-PME），只需延长drude ff即可覆盖带电的 脂质特别注意离子与极性头组的强相互作用（AIM 1）。然后我们会 使用精致的Drude FF研究基本方面生物膜静电并阐明 电子极化对生物膜基本静电特征的贡献（AIM 2）研究经典的ζ电位概念和膜结合电压敏感的特性 具有可极化模型的染料，用于地面和激发态。最后，我们将发展准确的两极分化 磷脂酰肌醇-4,5-双磷酸盐（PIP2）的模型，特别注意与与 单价和二价阳离子研究离子诱导的结构域的形成和PIP2的侧向聚类（AIM 3）。