RATIONALLY DESIGNED ANALOGS OF AMPHIPATHIC HELIXES

合理设计的两亲螺旋类似物

• 批准号: 6327708
• 负责人: Jere P Segrest
• 金额: $ 17.62万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2001-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6327708
• 关键词: X ray crystallography; amphiphilicity; apolipoproteins; blood lipoprotein metabolism; chemical binding; chemical models; enzyme activity; fluorescent dye /probe; hydropathy; infrared spectrometry; interferometry; intermolecular interaction; model design /development; nuclear magnetic resonance spectroscopy; peptide analog; peptide chemical synthesis; phosphatidylcholine sterol acyltransferase; protein sequence; protein structure; protein structure function; synthetic peptide

Abstract. The primary role of this project in the past, using peptide analogs of the amphipathic alpha helix, has been to experimentally test various hypotheses related to the structure and function of the amphipathic helical domains of apolipoproteins. The objective of the present project is to continue testing newly conceived hypotheses regarding structure-function relationships in apolipoproteins using more sophisticated experimental methods than used previously. This approach has already yielded new high-resolution structural information. Specific aims proposed are: (1) Development of rigorous computer algorithms to predict the structure of apolipoproteins associated with the surface of lipoprotein particles. (2) Studies of the determinants of lipid affinity and LCAT activation. (a) Depth of lipid penetration. The depth of lipid penetration of amphipathic helixes will be determined using fluorescence quenching and neutron diffraction. (b) Relative hydrophobicity of different amino acid residues. A hydrophobicity scale will be developed for each amino acid residue that is indexed to depth of lipid penetration. The approach will be to measure partition coefficients as the helix position and depth of penetration of a guest amino acid residue is varied within a host amphipathic alpha helix. ~ Orientation of the amphipathic helixes. Helix orientation in the discoidal complexes, lipid monolayers and supported lipid bilayers will be determined by polarized attenuated total reflectance fourier-transform infrared spectroscopy. (3) Structural studies of amphipathic alpha helixes in lipid or detergent complexes. (a) Two dimensional (2D) 1H- NHR studies of lipid complexes of amphipathic peptides. Based upon the exciting preliminary results obtained, we propose to initiate the structural studies of the amphipathic peptides in the presence of lipid using 2D 1H-NMR spectroscopy. (b) X-ray crystallography. In collaboration with Dr. Michael Garavito of Michigan State University, we propose to crystallize peptide analogs of amphipathic alpha helixes in the presence of detergents and/or lipids.

抽象的。 该项目过去的主要作用，使用 两亲性α螺旋的肽类似物 实验测试与结构相关的各种假设 载脂蛋白两亲性螺旋结构域的功能。 当前项目的目标是继续测试新的 关于结构与功能关系的设想假设 使用更复杂的实验方法检测载脂蛋白 比以前使用的。 这种方法已经产生了新的 高分辨率结构信息。 提出的具体目标 是：（1）开发严格的计算机算法来预测 与表面相关的载脂蛋白的结构 脂蛋白颗粒。 (2)脂质决定因素的研究 亲和力和 LCAT 激活。 (a) 脂质渗透深度。 这 两亲性螺旋的脂质渗透深度将为 使用荧光猝灭和中子衍射测定。 (b)不同氨基酸残基的相对疏水性。 一个 将为每种氨基酸制定疏水性等级 与脂质渗透深度相关的残留物。 方法 将测量分配系数作为螺旋位置和 客体氨基酸残基的渗透深度在 宿主两亲性α螺旋。 ~ 两亲性的方向 螺旋。 盘状复合物、脂质中的螺旋方向 单层和支持的脂质双层将由下式确定 偏振衰减全反射傅里叶变换红外 光谱学。 (3) 两亲性α螺旋的结构研究 在脂质或洗涤剂复合物中。 (a) 二维 (2D) 1H- 两亲性肽脂质复合物的 NHR 研究。 基于 根据所取得的令人兴奋的初步结果，我们建议 启动两亲性肽的结构研究 使用 2D 1H-NMR 光谱确定脂质的存在。 (b) X射线 晶体学。 与 Michael Garavito 博士合作 密歇根州立大学，我们建议结晶肽 去垢剂存在下的两亲性 α 螺旋类似物 和/或脂质。