Studying co-chaperone hHep1 interactions with membranes using TR-SAXS and stopped-flow rapid mixing

ssues related to protein misfolding and aggregation are central in diverse pathologies, from human diseases to cell stress adaptation failure by bacteria, and are a topic of interest for both fundamental and applied research. Proteins central in protein misfolding issue corrections are the molecular chaperones, essential for cell survival, which may also indirectly effect other processes. One such protein is the Hsp70-escort protein (hHep1), which has chaperone functions but is also essential for mitochondrial protein import. Here, we propose Time-Resolved Small Angle X-Ray Scattering (TR-SAXS) to address the role hHep1 has in this import process by using a stopped-flow rapid mixing setup, and to vary parameters such as membrane composition and temperature to simulate the mitochondrial membrane in different fluidity levels.

蛋白质错误折叠与聚集相关问题广泛存在于从人类疾病到细菌细胞应激适应失效等多种病理状态中，同时也是基础与应用研究共同关注的核心议题。在蛋白质错误折叠修复过程中发挥核心作用的是分子伴侣（molecular chaperones），这类蛋白对细胞存活至关重要，同时还可间接调控其他生理过程。其中一类关键分子伴侣为Hsp70 escort蛋白（Hsp70-escort protein，hHep1），其兼具分子伴侣功能，同时也是线粒体蛋白质输入过程不可或缺的核心因子。本研究拟采用停流快速混合装置，借助时间分辨小角X射线散射（Time-Resolved Small Angle X-Ray Scattering，TR-SAXS）技术解析hHep1在线粒体蛋白质输入过程中的作用机制，并通过调整膜组分与温度等参数，模拟不同流动性状态下的线粒体膜环境。