Conformational dynamics of OMPs, periplasmic chaperones and BamA

OMP、周质伴侣和 BamA 的构象动力学

• 批准号: 421343516
• 负责人: Professor Dr. Michael Schlierf
• 金额: --
• 依托单位: B CUBE - Center for Molecular Bioengineering
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/421343516?language=en
• 关键词: Conformational; dynamics; OMPs; periplasmic; chaperones

Outer membrane proteins maintain the viability of Gram-negative bacteria as receptors, transporters, ion channels, lipases, and porins. Folding and assembly of outer membrane proteins involves synchronized action of periplasmic chaperones and multi-protein machineries, which escort the highly hydrophobic polypeptides to their target outer membrane in a folding competent state. Over the past decades proteins and their biochemical function along the biogenesis pathway have been identified. Yet, the mechanisms of action and the intriguing ability of all these molecular machines to work without the typical cellular energy source of ATP, but solely based on thermodynamic principles are not well understood. In this application we aim to understand specific interactions of the periplasmic chaperones Skp and SurA with large outer membrane proteins, specific recognition sites and synergies of both chaperones. We will monitor these dynamics and structures using time-resolved single-molecule FRET, which allows us to reveal kinetics from the nanosecond to the minute timescale and spatial information from 2 to 8 nanometer. We further aim to reveal insights on the lateral gate dynamics of BamA and how those dynamics are influenced by the lipidic environment through reconstitution in artificial lipid bilayers and by preserving near native lipid compositions. We will further study how the lateral gate is influenced by other BAM proteins, by antibiotics and during insertion of OMP proteins. of the environment, direct interactions with other BAM proteins or antibiotics, and during insertion of OMP proteins.

外膜蛋白作为受体、转运蛋白、离子通道、脂肪酶和孔蛋白维持革兰氏阴性菌的活力。外膜蛋白的折叠和组装涉及周质分子伴侣和多蛋白机器的同步作用，其以折叠能力状态护送高度疏水的多肽到其靶外膜。在过去的几十年中，蛋白质及其生物合成途径上的生化功能沿着被确定。然而，所有这些分子机器的作用机制和有趣的能力在没有ATP典型细胞能量来源的情况下工作，而仅仅基于热力学原理，人们还没有很好地理解。在这个应用程序中，我们的目标是了解特定的周质分子伴侣Skp和SurA与大的外膜蛋白，特异性识别位点和两个分子伴侣的协同作用的相互作用。我们将使用时间分辨的单分子FRET来监测这些动力学和结构，这使我们能够揭示从纳秒到分钟的时间尺度和从2到8纳米的空间信息的动力学。我们进一步的目的是揭示BamA的横向门动力学的见解，以及这些动力学是如何通过人工脂质双层中的重建和保存近天然脂质组合物的生物环境的影响。我们将进一步研究其他BAM蛋白、抗生素和OMP蛋白插入过程中对侧门的影响。环境的影响，与其他BAM蛋白或抗生素的直接相互作用，以及OMP蛋白的插入过程。