单分子研究膜与蛋白相互作用

Membrane is the platform for proteins to survive and perform biological functions. Through transient or permanent association with proteins, cell membrane is involved in the hormones and neurotransmitters release, protein secretion, cell division, differentiation and contraction, gene expression and other complex biological processes. The critical step in the study of various physiological processes and disease mechanisms is to understand how membranes interacts with proteins. However, with strong focus on mechanistic insights, research about lipids to regulate protein function and structure, and to shape cell physiology has been restricted to a small number of proteins. This gap in our knowledge is due to a lack of methods that are amenable to systematically charting protein–lipid interactions. In this project, it is proposed to develop an assay which combines the magnetic tweezers and graphene surface-induced fluorescence attenuation (SIFA) to study the membrane protein interaction mechanism at the molecular level in a high temporal and spatial resolution. The interesting proteins are Synaptotagmin-1 and a few other proteins which also contain C2 domain and regulate neurotransmitters release. The goal is to understand how calcium sensitive proteins regulate neurotransmitter release precisely through interacting with membrane.

生物膜是蛋白生存和执行生物功能的平台。细胞膜通过与蛋白的瞬时或者永久的缔和作用，从而参与荷尔蒙和神经递质的释放、蛋白质分泌、细胞分裂、分化、收缩、基因表达等众多复杂生物学过程。理解膜与蛋白如何作用一直是研究各种生理过程以及疾病机理的核心步骤。然而，对于脂质如何调节蛋白质功能和结构以及影响最终生理学机制的研究仅限于少量体系。造成这种局面最重要的原因是由于缺乏可以系统地绘制蛋白质-脂质相互作用的方法。本项目以突触结合蛋白 Synaptotagmin-1 及相关调控神经递质释放的含 C2 结构域的蛋白为主要研究对象，拟发展将磁镊和氧化石墨烯表面诱导荧光衰减(SIFA)结合的高时间空间分辨技术，在分子水平上全方位研究蛋白与膜的相互作用机制，理解钙敏感蛋白如何通过与膜的相互作用来精准的激发和调控膜融合，实现神经递质释放。

生物分子间的相互作用是生物学过程的基础问题，生命体中几乎所有的生命过程的本质都是生物分子间作用力推动的结果。单分子技术可以帮助理解生物大分子之间的特异的相互作用，以及作用的动力学过程，从而帮助理解生命过程机理。我们致力于发展各种单分子技术和方法，在分子水平上，解析生物分子相互作用，定量揭示生命活动的机制。在本项目中，我们发展了单分子磁镊和氧化石墨烯表面诱导荧光衰减联合技术，用来系统地绘制蛋白质-脂质相互作用，在微观或者分子层面来理解膜与蛋白相互作用的本质，帮助理解膜与蛋白的相互作用在蛋白的生物功能中的角色等问题。我们按照申请书积极推进研究工作，努力实现预期的研究目标，取得了一系列成果。