Development of membrane protein structure analysis using heavy atom labeled lipids

2014 Fiscal Year Final Research Report

• Project/Area Number: 25650051
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Biophysics
• Research Institution: Osaka University
• Principal Investigator: SUGIYAMA SHIGERU 大阪大学, 理学(系)研究科(研究院), 特任准教授 (90615428)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 構造生物学 / 膜タンパク質結晶 / バイセル / 重原子標識脂質 / 結晶成長 / 重原子誘導体結晶 / 膜脂質 / 異常分散

Outline of Final Research Achievements

The specific lipids binding to membrane protein play a crucial role in membrane protein organization and function, resulting in a very important to elucidate the detailed mechanism of its specific lipid recognition. Membrane protein is crystallized after solubilization by detergents, although this treatment often disrupts innate structures and functions. Here we focused on crystallization of bacteriorhodopsin (bR) using various lipid bicelles as membrane mimicking systems. Bicells are small bilayer disks that form in lipid / amphiphile mixtures. Eight lipid bicelles were crystallized by mixing bR, resulting successfully in formation of bR-bicelle crystals. X-ray crystal structure analyses indicated that heavy atom labeled lipids are successfully incorporated into the bR-bicelle crystal, successfully interacting with bR. Our bicelle crystallization technique may be applicable for structurally unknown membrane proteins.

Free Research Field

生物学