LIGHT-DRIVEN ION TRANSPORT IN BACTERIAL RHODOPSINS

细菌视紫红质中的光驱动离子传输

• 批准号: 7924927
• 负责人: JANOS K LANYI
• 金额: $ 8.22万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2010-12-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7924927
• 关键词: 3-Dimensional; Aspartate; Attention; Bacterial Rhodopsins; Bacteriorhodopsins; Binding; Binding Sites; Charge; Chloride Ion; Coupling; Crystallography; Cytoplasmic Structures; DNA Sequence Rearrangement; Dissociation; Equilibrium; Face; Goals; Grant; Halorhodopsins; Hydrogen Bonding; Ion Pumps; Ion Transport; Ions; Learning; Molecular; Molecular Models; Nature; Pathway interactions; Phenotype; Proteins; Proton Pump; Protons; Recovery; Resolution; Retinal; Rhodopsin; Schiff Bases; Side; Site; Site-Directed Mutagenesis; Son; Specificity; Spectrum Analysis; Structure; Surface; Testing; Thermodynamics; Time; Water; Work; base; extracellular; molecular modeling; mutant; protonation; prototype

Bacteriorhodopsin and halorhodopsin are the simplest ion pumps, and prototypes of the ubiquitous seven-transmembrane-helical proteins. We have made unusual progress in the past years and now propose to test and extend the resulting detailed step-by-step hypothesis for the mechanism of proton transport. It includes not only the proton transfer steps in the protein but also the thermodynamic and structural rationales for the unidirectionality and the vectoriality of the ion translocation. All aspects of this comprehensive hypothesis are now open to critical examination, and in the proposed work we will pay particular attention to the numerous mutant phenotypes not predicted by its present version. We will continue to use our present approach of combining site- specific mutagenesis, time-resolved spectroscopy, and high-resolution protein x-ray crystallography to investigate i) structural questions at the proton release step, ii) howthe pK's of dissociable groups are modulated, Hi)the nature and causes of conformational coupling, iv) the mechanism of proton transport in the absence of asp-85 and asp-96, and v) the lessons to be learned from halorhodopsin and the D85T bacteriorhodopsin mutant, that both transport chloride ions and in the opposite direction from protons. The goal of this proposal is to establish, finally, a full and explicit model for the molecular mechanism of this kind of ion pump.

细菌紫红素和卤代紫红质是最简单的离子泵，无处不在的原型 七跨膜螺旋蛋白。在过去的几年中，我们取得了不寻常的进步 提议测试并扩展结果的详细分步假设 质子运输。它不仅包括蛋白质中的质子转移步骤，还包括 单向性和离子矢量性的热力学和结构性理由 易位。这一综合假设的所有方面现在都接受批判性检查， 在拟议的工作中，我们将特别注意众多突变表型 通过其当前版本进行预测。我们将继续使用我们目前的结合站点的方法 - 特定的诱变，时间分辨光谱和高分辨率蛋白X射线晶体学 调查i）在质子发行步骤中的结构性问题，ii）pk是如何可解离的 组进行调制，嗨）构象耦合的性质和原因，iv） 在没有ASP-85和ASP-96的情况下，质子运输，V）从中学到的教训 甲状腺素和D85T细菌紫红蛋白突变体，均转运氯离子和在 与质子相反的方向。该提议的目的是建立一个完整而明确的 这种离子泵的分子机制的模型。

项目成果

Molecular dynamics simulation of the unfolding of individual bacteriorhodopsin helices in sodium dodecyl sulfate micelles.

十二烷基硫酸钠胶束中单个细菌视紫红质螺旋展开的分子动力学模拟。

• DOI: 10.1021/bi201770y
• 发表时间: 2012
• 期刊: Biochemistry
• 影响因子: 2.9
• 作者: Krishnamani,Venkatramanan;Lanyi,JanosK
• 通讯作者: Lanyi,JanosK