Structures and lipid interactions of curvature-inducing membrane peptides by NMR

摘要 许多膜肽和蛋白质产生膜曲率以执行其功能。 实例包括阳离子肽，其通过形成永久性的膜而破坏或穿过脂质膜。 或瞬时孔和病毒融合蛋白 膜导致病毒进入。因此，阐明膜- 曲率诱导对于设计无耐药性抗生素和 研发新的疫苗和抗病毒药物。该项目的长期目标是 理解和量化曲率诱导膜肽的脂质特异性相互作用。我们 我将使用固态核磁共振作为我们的主要工具，因为它是唯一能够同时 探索膜蛋白的高分辨率结构，揭示膜蛋白的物理结构， 这些蛋白质嵌入的脂质膜的性质。我们提出了四 具体目标。1)我们将研究细菌中阳离子肽诱导的脂质聚集- 模拟膜细菌的阴离子和两性离子脂质的潜在分离 膜可能是促进膜弯曲的重要因素。同位素编辑NMR 将进行实验以测量脂质动力学和肽-脂质相互作用。 代表性的抗微生物和细胞穿透肽如PG-1和HIV达特将在本文中公开。 考察2)我们将发展~（31）P交换核磁共振技术， 脂质膜和阳离子肽在曲率不同的结构域中的定位。3)我们 将决定膜结合构象，动力学和插入的深度， 副粘病毒PIV 5的融合蛋白的融合肽和跨膜结构域。 PIV 5融合蛋白的结构信息将提供对PIV 5融合蛋白的机制的深入了解。 I类病毒融合蛋白的作用。4)我们将研究PIV 5的脂质相互作用， 使用2 H、31 P和1H NMR实验，对融合肽进行了分析。膜曲率，肽 定位和膜水合作用将被测量，以了解肽如何修饰 膜结构导致融合。

Abstract Many membrane peptides and proteins generate membrane curvature to carry out their function. Examples include cationic peptides that disrupt or cross lipid membranes by forming permanent or transient pores and viral fusion proteins that merge the virus envelope and the target cell membrane to cause virus entry. Thus, elucidating the fundamental mechanism of membrane- curvature induction has broad significance for designing resistance-free antibiotics and for developing new vaccines and antiviral drugs. The long-term objective of this project is to understand and quantify lipid-specific interactions of curvature-inducing membrane peptides. We will use solid-state NMR as our main tool, because it is uniquely capable of simultaneously probing the high-resolution structures of membrane proteins and revealing the physical properties of the lipid membrane in which these proteins are embedded. We propose four specific aims. 1) We will investigate cationic-peptide-induced lipid clustering in bacteria- mimetic membranes. Potential segregation of anionic and zwitterionic lipids of bacterial membranes may be a significant factor in promoting membrane curvature. Isotope-edited NMR experiments will be conducted to measure lipid dynamics and peptide-lipid interactions. Representative antimicrobial and cell-penetrating peptides such as PG-1 and HIV TAT will be examined. 2) We will develop 31P exchange NMR techniques to measure the curvature of mixed lipid membranes and the localization of cationic peptides in curvature-distinct domains. 3) We will determine the membrane-bound conformation, dynamics, and depth of insertion of the fusion peptide and transmembrane domain of the fusion protein of the paramyxovirus, PIV5. Structure information of the PIV5 fusion protein will provide insight into the mechanism of action of class I viral fusion proteins. 4) We will investigate the lipid interactions of the PIV5 fusion peptide using 2H, 31P, and 1H NMR experiments. Membrane curvature, peptide localization and membrane hydration will be measured to understand how the peptide modifies the membrane structure to cause fusion.