Membrane protein crystallography using new lipid

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K14688
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Structural biochemistry
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Ihara Kentaro 国立研究開発法人理化学研究所, ライフサイエンス技術基盤研究センター, 研究員 (90647207)
• Co-Investigator(Kenkyū-buntansha): 羽藤 正勝 国立研究開発法人理化学研究所, ライフサイエンス技術基盤研究センター, 嘱託職員 (40357786)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 膜タンパク質 / 脂質メソフェーズ結晶化 / イソプレノイド鎖型脂質 / Gタンパク質共役型受容体 / アデノシンA2A受容体

Outline of Final Research Achievements

Integral membrane proteins are crystallized in lipidic mesophase, mostly using monoacylglycerol (MAG) as crystallization matrix. However, almost no choice other than MAG is available so far. In such situation, we have shown that isoprenoid-chained lipid (IPCL) can be applicable to membrane protein crystallography. Structurally, IPCL has unique saturated alkyl chain with methyl branches realizing stable lipidic mesophase at non-freezing low temperature compared to MAG. Our project aims to show that IPCL can be a crystallization matrix for membrane protein in wide temperature range. As a representative of G protein coupled receptor (GPCR), adenosine A2A receptor was crystallized using IPCL, and crystal structures could be determined at cryogenic temperature and two non-freezing temperatures, 4 and 20°C. Our results suggest that IPCL is useful for human membrane protein crystallization, and expands experimental temperature range.

Free Research Field

タンパク質の結晶構造解析