Membrane Protein Stability

膜蛋白稳定性

• 批准号: 8970707
• 负责人: Karen G. Fleming
• 金额: $ 33.96万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2017-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8970707
• 关键词: Achievement; Address; Basic Science; Binding; Biological; Biophysical Process; Biophysics; Burial; Cell physiology; Charge; Chemicals; Computer Simulation; Coupling; Data; Dependence; Disease; Engineering; Equilibrium; Escherichia coli; Free Energy; Goals; Grant; Head; Health; Human body; Hydrophobicity; Kinetics; Knowledge; Lead; Lipids; Location; Marketing; Measurement; Measures; Membrane; Membrane Proteins; Modeling; Molecular; Molecular Conformation; Mutation; Organic solvent product; Pharmaceutical Preparations; Play; Positioning Attribute; Process; Protein Engineering; Proteins; Regulation; Research; Role; Scaffolding Protein; Side; Site; Sorting - Cell Movement; Specific qualifier value; Structural Genes; Structure; Testing; Therapeutic; Thermodynamics; Water; Work; aspartylglutamate; base; biophysical analysis; biophysical techniques; combat; design; driving force; insight; microbial; microorganism; mutant; novel; protein folding; protein misfolding; protein structure; research study; scaffold

DESCRIPTION (provided by applicant): Membrane proteins play essential roles in many cellular processes. The overall goal of the proposed research is to understand the physical basis of the protein folding process and the biophysical basis of membrane protein structures. At present, neither of these is well understood for membrane proteins. Thermodynamically, our work addresses the critical role that hydrophobicity plays in membrane protein folds. In the previous granting period, we developed a novel hydrophobicity scale that measures side-chain transfer free energies from water to the membrane center using a real bilayer and a real, folded membrane protein. Based on this achievement, we now propose to test the generality of this scale (1) By measuring side-chain transfer free energies using distinct membrane protein scaffolds; (2) By determining how extent-of-burial in the bilayer modulates water to bilayer transfer free energies; and (3) By engineering of our protein scaffold for measurements as a function of pH to address how the energetic consequences of ionizable group mutations vary with charge state. Kinetically, we discovered in the previous grant period that E. coli lipid head groups may act as energetic potentials that sort membrane proteins away from the wrong (inner) membranes and towards the correct (outer) membrane locations. We propose in a fourth aim to dissect the biophysical basis for this sorting by determining the kinetic lifetimes and conformations and activation energies to folding induced by E. coli-containing lipid head groups.

描述（由申请人提供）：膜蛋白在许多细胞过程中起重要作用。拟议研究的总体目标是了解蛋白质折叠过程的物理基础和膜蛋白结构的生物物理基础。目前，对于膜蛋白而言，这两个都不是很好的理解。 从热力学上讲，我们的工作解决了疏水性在膜蛋白褶皱中起的关键作用。在上一个授予期间，我们开发了一种新颖的疏水性量表，该量表可以使用真实的双层和真实的，折叠的膜蛋白来测量从水到膜中心的侧链转移自由能。基于这一成就，我们现在建议通过使用不同的膜蛋白支架测量侧链转移能量来测试该量表（1）的通用性； （2）通过确定双层中的含量如何调节水向双层转移的自由能； （3）通过工程化我们的蛋白质支架来测量pH的函数，以解决可电离组突变的能量后果如何随电荷状态而变化。 在动力上，我们在上一个赠款时期发现了大肠杆菌头 组可能充当能量电位，将膜蛋白从错误的（内部）膜和正确的（外部）膜位置排成。我们提出第四个目标，以通过确定动力学寿命，构象和激活能的生物物理基础来剖定这种分类，以使含大肠杆菌的脂质脂质头基诱导的折叠能量。