Understanding How Integral Membrane Proteins Influence the Continuum Mechanics of Cell Membranes.

了解完整膜蛋白如何影响细胞膜的连续体力学。

基本信息

批准号：
1915017
负责人：
Noah Malmstadt
金额：
$ 35万
依托单位：
University of Southern California
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-01 至 2022-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1915017&HistoricalAwards=false
关键词：
Understanding How Integral Membrane Proteins

项目摘要

The goal of this proposal is to establish experimental techniques and develop foundational experimental data describing how general integral membrane proteins affect the mechanical properties of biomembranes. These tools and results will have a transformative effect on our understanding of biomembranes as continuum materials. Most contemporary research in bilayer-protein interactions focuses either on how specific proteins (SNARE complexes, viral fusion proteins) exert force on lipid bilayers or how forces in the lipid bilayer can modulate integral membrane protein function. The PI is looking at the membrane as a continuum material in which the mechanical properties are determined by both the lipids and the integral membrane proteins. Given the high concentration of proteins in the membrane, such a view is necessary in order to fully understand how biomembranes move and deform. Membrane deformation is a central phenomenon in biology, underlying such processes as cell division, viral infection, and neurotransmitter release. This proposal includes a comprehensive educational plan for outreach to high school students. The primary objective of this outreach program is to facilitate intensive research experiences for students drawn from the diverse population of the Los Angeles Unified School District. This will be accomplished by cooperating with an established outreach program at the Engineering for Health Academy at Francisco Bravo Medical Magnet High School to bring grade-12 students into the laboratory for yearlong internships. Interns will be mentored by the graduate student funded by this award and will undertake their own small, independent research projects.The PI will use standard methods for measuring the mechanical properties of lipid bilayers in giant unilamellar lipid vesicles (GUVs). The key innovative aspect of this research is enabled by a technology that the PI's laboratory recently developed to incorporate integral membrane proteins into GUVs at relatively high concentrations. This will allow the PI to examine the mechanical properties on GUVs with controlled concentrations of membrane proteins. The PI will investigate proteins with a variety of transmembrane motifs to discover how the structure of the transmembrane domains affects how proteins are mechanically coupled to the bilayer. The two properties that will be measured for each protein at a range of concentrations are: 1.) The tendency of a membrane to bend when no external forces are applied. This is described by the spontaneous (or intrinsic) curvature JSB. 2.) The amount of energy required to bend the membrane away from its intrinsic curvature. This is described by the bending modulus kc. These two parameters are central to describing the energetics of membrane deformation during biological processes. The PI will use a combination of micropipette aspiration and vesicle fluctuation analysis to independently determine the value of each parameter for a given set of conditions.This project is being jointly supported by the Physics of Living Systems program in the Division of Physics and the Molecular Biophysics program in the Division of Molecular and Cellular Biosciences.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该建议的目的是建立实验技术并开发基础实验数据，描述一般整合膜蛋白如何影响生物膜的机械性能。这些工具和结果将对我们对生物膜作为连续材料的理解具有变革性的影响。双层蛋白质相互作用的大多数当代研究都集中在特定蛋白（圈圈复合物，病毒融合蛋白）如何对脂质双层发挥作用，或者脂质双层中的力如何调节整体膜蛋白蛋白功能。 PI将膜视为连续材料，其中机械性能由脂质和积分膜蛋白决定。鉴于膜中蛋白质的高浓度，因此需要这种观点，以充分了解生物膜如何移动和变形。膜变形是生物学中的一种核心现象，其基础是细胞分裂，病毒感染和神经递质释放等过程。该建议包括一项全面的教育计划，以向高中生推广。该外展计划的主要目标是促进从洛杉矶统一学区各种人群中吸引的学生进行深入的研究经验。这将是通过与弗朗西斯科·布拉沃医学磁铁高中的健康学院的一项既定的外展计划合作来实现的，将12年级的学生带入实验室，以进行为期一年的实习。实习生将由该奖项资助的研究生指导，并将进行自己的小型独立研究项目。PI将使用标准方法来测量巨型Unilamellar脂质囊泡（GUV）中脂质双层的机械性能。这项研究的关键创新方面是由PI的实验室最近开发出的技术来实现的，该技术将整体膜蛋白纳入相对较高浓度的GUV中。这将使PI可以检查具有控制浓度的膜蛋白的GUV上的机械性能。 PI将研究具有多种跨膜基序的蛋白质，以发现跨膜结构域的结构如何影响蛋白质如何机械耦合到双层。每种蛋白质将在一定浓度范围内测量的两种特性为：1。）膜在不施加外力时弯曲的趋势。这是由自发（或固有）曲率JSB描述的。 2.）弯曲膜从其固有曲率弯曲所需的能量。这是由弯曲模量KC描述的。这两个参数对于描述生物过程中膜变形的能量学至关重要。 PI将利用微孔放气和囊泡波动分析的组合独立确定给定条件的每个参数的价值。该项目在物理学和分子生物物理学部门的生命系统计划和分子生物物理学计划中共同支持，并通过分子和细胞生物科学的裁决来反映出NSF的代理，并反映了nsf的代表。智力优点和更广泛的影响审查标准。