Determinants of Fold Stability in Proteins and Analogues

蛋白质和类似物折叠稳定性的决定因素

• 批准号: 7926143
• 负责人: SAMUEL H. GELLMAN
• 金额: $ 9.99万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7926143
• 关键词: Address; Adopted; Adoption; Affinity; Amino Acid Sequence; Amino Acids; Area; Base Sequence; Behavior; Binding; Bioinformatics; Chemicals; Chemistry; Collaborations; Development; Diamines; Engineering; Environment; Funding; Goals; Guidelines; Higher Order Chromatin Structure; Laboratories; Length; Life; Link; Lipid Bilayers; Membrane; Membrane Proteins; Metabolic; Methods; Micelles; Molecular; Molecular Conformation; Organic Synthesis; Organism; Pattern; Peptides; Proteins; Relative (related person); Reporting; Research; Science; Sequence Analysis; Side; Solutions; Source; Structure; System; Techniques; Testing; Thermodynamics; Vertebral column; Water; Work; analog; base; beta pleated sheet; comparative; design; dimer; experience; flexibility; inhibitor/antagonist; insight; interest; interfacial; membrane model; mimetics; novel; polypeptide; preference; programs; protein folding; protein function; protein structure; public health relevance; structural biology; success; thioester; tool

DESCRIPTION (provided by applicant): Our research is intended to elucidate the origins of specific folding and assembly behavior displayed by proteins. Proteins perform a vast array of functions that are essential for life, and protein activity usually depends on the adoption of higher order structure by the polypeptide chain. Therefore, understanding the factors that control folding and assembly, i.e., secondary, tertiary and often quaternary structure formation, for a given sequence of amino acid residues is a fundamental scientific goal. Our research employs standard characterization tools; in addition, we strive to create new tools that offer unique approaches to important questions. For example, we are developing a set of novel molecular units that enable thermodynamic analysis of parallel beta-sheet secondary structure, and one current goal is to use these tools to elucidate how basic parameters such as number of strands or length of strands influence parallel beta-sheet stability. Our unique tools in this case are unnatural diamine or diacid segments that link peptide segments via their C- or N-termini and promote parallel beta-sheet formation in water. Such linkers are not available in classical protein science, and this research requires a laboratory, such as ours, that has experience in both biophysical characterization and organic synthesis. Another chemical tool recently developed by our group, the "backbone thioester exchange" (BTE) method, offers a unique approach to analysis of sequence-stability correlations at secondary, tertiary and/or quaternary structure levels in small polypeptides. The proposed research includes the use of BTE to probe the factors that govern affinity and selectivity in side-by-side interactions between alpha-helical segments (e.g., coiled-coils). Helix-helix association is a prominent feature of protein tertiary and quaternary structure, and our studies will address previously unanswered questions in this area. In addition, we propose to extend BTE to the study of helix-helix interactions in lipid bilayers. Current understanding of the forces that control protein folding and association in membranes is underdeveloped relative to what is known about proteins in solution, and a major stumbling block in the membrane protein field is lack of effective methods for thermodynamic analysis of structural phenomena. BTE could represent a powerful new tool in this field. We want to extend our understanding beyond proteins to unnatural oligomers that display protein-like structures. Such efforts will broaden fundamental understanding of the ways in which networks of noncovalent interactions control the conformations and binding propensities of flexible oligomers. In addition, this component of our research is motivated by the long-term prospect that unnatural oligomers with well-understood folding rules could provide a basis for creating new kinds of biomedically useful agents. PUBLIC HEALTH RELEVANCE Proteins are the workhorse molecules of life. The functions of proteins depend critically on the structures they adopt, and a major goal of our work is to elucidate factors that govern protein structure. Unnatural molecules that display protein-like structural behavior could ultimately be engineered to display biomedically useful protein-like functions, and our goals include the discovery and characterization of new protein-mimetic systems.

描述（由申请人提供）：我们的研究旨在阐明蛋白质表现出的特定折叠和组装行为的起源。蛋白质执行生命所必需的多种功能，蛋白质活性通常取决于多肽链对更高阶结构的采用。因此，对于给定的氨基酸残基序列，了解控制折叠和组装（即二级、三级和通常四级结构形成）的因素是一个基本的科学目标。我们的研究采用标准表征工具；此外，我们努力创建新工具，为重要问题提供独特的方法。例如，我们正在开发一组新颖的分子单元，能够对平行 β 折叠二级结构进行热力学分析，当前的一个目标是使用这些工具来阐明基本参数（例如链数或链长度）如何影响平行 β 折叠-板材稳定性。在这种情况下，我们独特的工具是非天然二胺或二酸片段，它们通过其 C 或 N 末端连接肽片段，并促进水中平行 β 片层的形成。这种连接子在经典蛋白质科学中是不可用的，这项研究需要一个像我们这样在生物物理表征和有机合成方面都具有经验的实验室。我们小组最近开发的另一种化学工具“骨架硫酯交换”（BTE）方法提供了一种独特的方法来分析小多肽中二级、三级和/或四级结构水平的序列稳定性相关性。拟议的研究包括使用 BTE 来探测控制 α 螺旋片段（例如卷曲螺旋）之间并排相互作用的亲和力和选择性的因素。螺旋-螺旋缔合是蛋白质三级和四级结构的一个显着特征，我们的研究将解决该领域以前未解答的问题。此外，我们建议将 BTE 扩展到脂质双层中螺旋-螺旋相互作用的研究。相对于对溶液中蛋白质的了解，目前对控制膜中蛋白质折叠和缔合的力的理解还不够成熟，膜蛋白质领域的一个主要障碍是缺乏对结构现象进行热力学分析的有效方法。 BTE 可以代表该领域的一个强大的新工具。我们希望将我们的理解扩展到蛋白质以外的显示类似蛋白质结构的非天然寡聚物。这些努力将拓宽对非共价相互作用网络控制柔性寡聚物的构象和结合​​倾向的方式的基本理解。此外，我们研究的这一部分的动机是长期前景，即具有充分理解的折叠规则的非天然低聚物可以为创造新型生物医学有用试剂提供基础。公共卫生相关性 蛋白质是生命的主力分子。蛋白质的功能很大程度上取决于它们采用的结构，我们工作的主要目标是阐明控制蛋白质结构的因素。表现出类蛋白质结构行为的非天然分子最终可以被设计为表现出生物医学上有用的类蛋白质功能，我们的目标包括发现和表征新的蛋白质模拟系统。