Kinetics and Morphology of Self-Associating Beta-Sheet Peptides

许多肽和蛋白质自发地自缔合成交叉β-折叠结构和纤维形态的大聚集体，这可能对多种细胞类型有毒，这仅仅是由于它们的形态而不是它们的特定序列。因此，需要阐明控制肽自缔合成纤维状聚集体的因素，以了解疾病的机制，开发这些疾病的治疗策略，并设计用于蛋白质制造和制剂的有效工艺。本研究的目标是：（1）开发纤维形成肽和蛋白质组装动力学的详细数学模型，（2）设计和合成纤维形成肽，其中通过骨架氢键和侧链-侧链相互作用的明智平衡来控制形态，以及（3）开发规则来预测相互作用的肽对是否将具有比单独的每个肽更大或更小的聚集倾向。三个模型系统将用于追求这些目标：（1）胰岛素和胰岛素类似物，（2）脱辅基肌红蛋白截短突变体，和（3）聚谷氨酰胺和其他扩展结构域肽。组装的动力学使用几种互补的实验技术进行监测：静态和动态光散射，

0330537MurphyMany peptides and proteins spontaneously self-associate into large aggregates of cross beta-sheet structure and fibrillar morphology, which may be toxic to a wide number of cell types, due simply to their morphology and not to their specific sequence. Thus, elucidation of the factors that control peptide self-association into fibrillar aggregates is needed to understand mechanisms of disease, to develop therapeutic strategies for these diseases, and to design efficient processes for protein manufacture and formulation. The objectives of this research are: (1) to develop a detailed mathematical model of the kinetics of assembly of fibril-forming peptides and proteins, (2) to design and synthesize fibril-forming peptides in which morphology is controlled by judicious balancing of backbone hydrogen-bonding and side chain-side chain interactions, and (3) to develop rules to predict whether pairs of interacting peptides will have greater or lesser aggregation propensity than each peptide in isolation. Three model systems will be used in pursuing these objectives: (1) Insulin and insulin analogs, (2) Apomyoglobin truncation mutants, and (3) Polyglutamine and other expanded-domain peptides. Kinetics of assembly are monitored using several complementary experimental techniques: static and dynamic light scattering,