Rules for Helix Intiation, Propagation, and Termination

螺旋起始、传播和终止的规则

• 批准号: 6839977
• 负责人: GEORGE I MAKHATADZE
• 金额: $ 26.42万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-05-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6839977
• 关键词: aminoacid; bioenergetics; calcium binding protein; calmodulin; calorimetry; chemical stability; circular dichroism; conformation; hydrogen bond; mathematics; nuclear magnetic resonance spectroscopy; pancreatic polypeptide; physical chemical interaction; protein folding; protein protein interaction; protein sequence; protein structure function; site directed mutagenesis; thermodynamics; ubiquitin

DESCRIPTION (provided by applicant): The long-term goal of this research program is to understand the detailed physico-chemical basis for the mechanism of protein stability. The function of proteins requires translation of the information encoded by a linear polypeptide sequence into a specific three-dimensional structure. The relationship between protein function, structure and stability is complex. Small perturbations such as single-site mutations can alter protein function, trafficking, degradation rate or solubility, leading to cellular abnormalities that, in some cases, are lethal. However, proteins also possess a great degree of plasticity and there are large number of amino acid mutations that do not affect the overall structure or function. The knowledge of the relationship between sequence, structure and stability is critical for, not only a deeper understanding of biological systems, but also for the development of approaches that allow rational design of new protein structures and enhanced stabilities of biologically active proteins. This can be used in biotechnology for improving human well-being and health. The present research proposal aims to understand how the amino acid sequence determines the stability and specificity of alpha-helical segments, both in solution and within protein structure, and to identify the universal and specialized determinants for protein stability. The four broad questions to be answered are: (1). What is the mechanism of stabilization of the N-termini of a-helices? (2). What is the contribution of the backbone conformation and hydrogen bonding at the C-terminus to the stability of the a-helix? (3). What is the contribution of the enthalpy of helix-coil transition to the helix propensity scale? (4). What is the contribution of helix-coil transition to the energetics of protein-protein interactions? To answer these questions, experiments, that include site-directed mutagenesis, calorimetry, fluorescence, circular dichroism and NMR spectroscopies, and computational approaches, will be applied to the model proteins ubiquitin, human pancreatic polypeptide, calmodulin and S100P, and short monomeric peptides.

描述（由申请人提供）：该研究计划的长期目标是了解蛋白质稳定性机理的详细物理化学基础。 蛋白质的功能需要将线性多肽序列编码的信息转换为特定的三维结构。 蛋白质功能，结构和稳定性之间的关系很复杂。 小扰动（例如单位点突变）可以改变蛋白质功能，运输，降解率或溶解度，导致细胞异常，在某些情况下是致命的。 但是，蛋白质也具有很大的可塑性，并且有大量不影响整体结构或功能的氨基酸突变。 对序列，结构和稳定性之间关系的了解对于不仅对生物系统的深入了解至关重要，而且对于允许合理设计新蛋白质结构以及增强生物活性蛋白质稳定性的方法的发展至关重要。 这可以用于生物技术来改善人类的福祉和健康。 本研究建议旨在了解氨基酸序列如何确定溶液和蛋白质结构内α-螺旋段的稳定性和特异性，并确定蛋白质稳定性的通用和专业决定因素。 要回答的四个广泛问题是：（1）。 A螺旋的N末端稳定的机制是什么？ （2）。 C末端对A螺旋稳定性的主干构象和氢键的贡献是什么？ （3）。 螺旋线圈向螺旋倾向量表的焓焓的贡献是什么？ （4）。 螺旋线圈向蛋白质蛋白质相互作用的能量学的贡献是什么？为了回答这些问题，包括位于定位的诱变，量热法，荧光，圆形二色性和NMR光谱的实验以及计算方法，将应用于模型蛋白质泛素，人类胰腺多肽，钙调蛋白，钙调蛋白和S100P，以及短单位蛋白质的peptides。