Membrane-active Peptides and Proteins

膜活性肽和蛋白质

基本信息

批准号：
7923490
负责人：
HUEY W. HUANG
金额：
$ 23.5万
依托单位：
RICE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-09-30 至 2011-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7923490
关键词：
Adopted Animals Apoptosis Apoptosis Regulator Apoptotic Area Bax protein Binding Biological Process Cancerous Cell Death Cell membrane Cells Cholesterol Circular Dichroism Clinical Trials Confusion Cytosol Dependence Development Exhibits Free Energy Genes Goals Grant HIV Envelope Protein gp41 Hemagglutinin Human Individual Kinetics Lipids Measures Membrane Membrane Fusion Membrane Proteins Methods Microbe Molecular N-terminal Neutron Diffraction Outer Mitochondrial Membrane Peptides Phase Physiological Play Positioning Attribute Principal Investigator Process Proteins Reaction Research Respiratory Diaphragm Roentgen Rays Role Simulate Solutions Stimulus Structure Surface Suspension substance Suspensions System Testing Therapeutic Thick Vesicle Viral Fusion Proteins Work X ray diffraction analysis X-Ray Diffraction abstracting antimicrobial antimicrobial peptide aqueous base cancer cell cytochrome c insight killings peptide structure physical state porin programs protein complex research study response theories

项目摘要

Program Director/Principal Investigator (Last, First, Middle): PROJECT SUMMARY/ABSTRACT We propose to study membrane-active proteins and peptides that cause configurational changes in cell membranes, including pore formation and membrane fusion. Pore-forming peptides are animals' (including human's) gene-encoded innate antimicrobials that kill microbes by forming pores in their membranes. Clarification of their molecular mechanisms will facilitate their therapeutic applications. Our studies of this problem have led to a free energy description of peptide-lipid interactions. In specific aim 1 we will extend such studies to the kinetics of pore-formation. Studies of these relatively simple peptides have also contributed to the development of experimental methods that can be used for more complex protein-membrane interactions. Pore-forming proteins include apoptosis regulating proteins, in particular Bax which is soluble in the cytosol under normal conditions, but in the presence of apoptotic stimuli, it translocates to the outer mitochondrial membrane and induces cytochrome c release by forming pores. In specific aim 2, we will analyze the molecular mechanism of pore formation by Bax. The viral fusion protein (hemagglutinin or HIV gp41) inserts the N-terminal fusion peptide into the target membrane to initiate membrane fusion. In specific aim 3 we will study the effect of fusion peptides on the first step of membrane fusion. The molecular mechanisms of membrane-peptide (or -protein) interactions must have a structural basis. Obtaining the structural information for each system is our primary goal. Using oriented membranes containing peptides, we have developed methods for measuring the orientation of the peptides, measuring the membrane thickness as a function of peptide-lipid ratio, detecting and measuring the size of transmembrane pores, and resolving the structures of the peptide-induced pores. We will extend these methods to study pore-forming proteins. The biological functions of membrane-active proteins and peptides will be simulated in kinetic experiments with giant unilamellar vesicles (GUVs). The surface area change and the volume change of the GUV in the kinetic process will be measured. We will then interpret the kinetic results in terms of the structural basis. PHS 398/2590 (Rev. 11/07) Page Continuation Format Page

计划主任/首席研究员（最后，第一，中间）：项目摘要/摘要我们建议研究引起细胞构型变化的膜活性蛋白和肽膜，包括孔形成和膜融合。形成孔的肽是动物（包括人类的）基因编码的先天抗菌药物，这些抗菌剂通过在其膜上形成毛孔来杀死微生物。澄清其分子机制将有助于其治疗应用。我们对此的研究问题导致了肽 - 脂质相互作用的自由能量描述。在特定目标1中，我们将扩展此类研究孔形成动力学。这些相对简单肽的研究也有有助于开发实验方法，可用于更复杂的蛋白质包机互动。形成孔的蛋白包括调节蛋白质的凋亡，特别是Bax，它可溶于在正常条件下的细胞质，但在存在凋亡刺激的情况下，它易位到外部线粒体膜并通过形成毛孔诱导细胞色素c释放。在特定的目标2中，我们将通过Bax分析孔形成的分子机制。病毒融合蛋白（血凝素或HIV GP41）将N末端融合肽插入靶膜中以启动膜融合。具体目标3我们将研究融合肽对膜融合的第一步的影响。分子膜肽（或 - 蛋白质）相互作用的机理必须具有结构性基础。获得每个系统的结构信息是我们的主要目标。使用含有肽的定向膜，我们已经开发了测量肽方向的方法，将膜厚度测量为肽 - 脂质比的功能，检测和测量跨膜孔的大小，并解决肽诱导的孔的结构。我们将扩展这些方法以研究形成孔的蛋白质。这膜活性蛋白和肽的生物学功能将在动力学实验中模拟巨型单层囊泡（GUVS）。表面积的变化和动力学中GUV的体积变化过程将被衡量。然后，我们将根据结构基础来解释动力学结果。 PHS 398/2590（Rev. 11/07）页面延续格式页面