BACKBONE EFFECTS ON PROTEIN STABILITY AND FOLDING

主链对蛋白质稳定性和折叠的影响

• 批准号: 6636309
• 负责人: PHILIP E DAWSON
• 金额: $ 27.07万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2005-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6636309
• 关键词: X ray crystallography; analytical ultracentrifugation; chemical kinetics; chymotrypsin inhibitor; circular dichroism; combinatorial chemistry; fluorescence spectrometry; matrix assisted laser desorption ionization; peptide chemical synthesis; protein engineering; protein folding; protein sequence; protein structure function; stop flow technique; thermodynamics; thermostability

The objective of this research program is to understand the relationship between the molecular structure of a polypeptide chain and its ability to fold into a defined, three-dimensional structure. Understanding of the molecular basis for the processes of folding and stability is central to biomedical science and represents one of the fundamental unsolved problems in molecular biology. Most studies on protein folding and stability have focused on the role of amino acid sidechains using site-directed mutagenesis. We propose to diverge from this trend by using the total synthesis of proteins to chemically modify the polypeptide backbone. We believe that systematic variation of the backbone will give new insights into the fundamental forces that stabilize proteins and the processes through which they fold. We have demonstrated the ability to chemically synthesize and introduce backbone modifications into two well-defined protein systems, the GCN-4 coiled coil and the chymotrypsin inhibitor CI- 2. In the context of these two systems, we plan to probe the following interactions. 1) The effects of single (-CONH-) to (- COO-) replacements in the backbone of protein helices. 2) The utility of 'double backbone mutant' cycles on the local backbone interactions in alpha helices. 3) The effects of backbone modifications on non-local interactions using the combinatorial assembly of backbone-engineered peptides. 4) The chemical feasibility of creating all ester polymers with protein-like folding properties. The long-term goal of this work is to merge of the fields of biomimetic and natural product chemistry with molecular biology and protein engineering. The systematic application of the tools of synthetic chemistry of protein molecules will create a new platform for the understanding of the molecular basis of protein function.

该研究计划的目的是了解多肽链的分子结构与其折叠成确定的三维结构的能力之间的关系。 了解折叠和稳定性过程的分子基础是生物医学的核心，也是分子生物学中未解决的基本问题之一。 大多数关于蛋白质折叠和稳定性的研究都集中在使用定点诱变的氨基酸侧链的作用上。 我们建议通过使用蛋白质的全合成来化学修饰多肽主链来摆脱这种趋势。 我们相信，主链的系统变异将为稳定蛋白质的基本力及其折叠过程提供新的见解。我们已经证明了化学合成并将主链修饰引入两个明确的蛋白质系统（GCN-4 卷曲线圈和胰凝乳蛋白酶抑制剂 CI-2）的能力。在这两个系统的背景下，我们计划探讨以下相互作用。 1) 蛋白质螺旋主链中单个 (-CONH-) 到 (-COO-) 替换的影响。 2)“双主链突变体”循环对α螺旋中局部主链相互作用的效用。 3) 使用主链工程肽的组合组装进行主链修饰对非局部相互作用的影响。 4) 制造具有类蛋白质折叠特性的所有酯聚合物的化学可行性。这项工作的长期目标是将仿生和天然产物化学领域与分子生物学和蛋白质工程融合。 蛋白质分子合成化学工具的系统应用将为理解蛋白质功能的分子基础创建一个新的平台。