Studying Dynamics and Energetics of Membrane Protein Oligomerization using Single Molecule Fluorescence

使用单分子荧光研究膜蛋白寡聚的动力学和能量学

• 批准号: RGPIN-2017-06871
• 负责人: Blunck, Rikard
• 金额: $ 3.28万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712476
• 关键词: Studying; Dynamics; Energetics; Membrane; Protein

The cell wall, or cell membrane, is composed of a double-layered lipid film and proteins, functional macromolecules that control electrical signals and substrate transport in and out of the cell. Membrane proteins also sense external stimuli and trigger signaling cascades in the inside. Until recently, the lipid membrane itself was considered mainly a passive matrix that separates the cell interior from the exterior. However, recently, it became increasingly clear that the composition of the lipid membrane influences the functioning of the proteins. This also relates to our nutrition; compounds such as cholesterol and omega-3 are known to enter the lipid film, alter its properties and modulate protein function. Conversely, also the proteins embedded in the lipid membrane alter its phase behaviour and form. Many proteins oligomerize to larger complexes or clusters. We found recently that clustering of a membrane protein, the proton-gated KcsA channels, is related to deformations of the membrane. In this research program, we investigate the energetics of protein oligomerization and membrane deformations and their implication on protein function. We will directly observe the dynamics of protein oligomerization using single molecule fluorescence, where we can follow the movement of the proteins in an artificial membrane and determine the energy landscape of the clustering process. We will determine the effect of membrane curvature on protein function and oligomerization and characterize which classes of membrane proteins undergo lipid-mediated clustering.

细胞壁或细胞膜由双层脂质膜和蛋白质、控制电信号和底物进出细胞的功能性大分子组成。膜蛋白还感知外部刺激并触发内部信号级联。直到最近，脂质膜本身主要被认为是一种将细胞内部与外部分开的被动基质。然而，最近人们越来越清楚，脂质膜的组成会影响蛋白质的功能。这也与我们的营养有关；众所周知，胆固醇和 omega-3 等化合物会进入脂质膜，改变其特性并调节蛋白质功能。相反，嵌入脂质膜中的蛋白质也会改变其相行为和形式。 许多蛋白质寡聚成更大的复合物或簇。我们最近发现膜蛋白（质子门控 KcsA 通道）的聚集与膜的变形有关。在这个研究项目中，我们研究了蛋白质寡聚和膜变形的能量学及其对蛋白质功能的影响。我们将使用单分子荧光直接观察蛋白质寡聚的动态，我们可以跟踪蛋白质在人造膜中的运动并确定聚类过程的能量景观。我们将确定膜曲率对蛋白质功能和寡聚化的影响，并表征哪些类别的膜蛋白经历脂质介导的聚类。