Mechanism Analysis of Interaction between Membrane and a Glycolipid Essential for Membrane Protein Integration

2015 Fiscal Year Final Research Report

• Project/Area Number: 25620137
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Bio-related chemistry
• Research Institution: Suntory Foundation for Life Sciences
• Principal Investigator: SHIMAMOTO Keiko 公益財団法人サントリー生命科学財団, その他部局等, その他 (70235638)
• Co-Investigator(Renkei-kenkyūsha): MIURA Kaoru (Nomura Kaoru) (公益財団法人)サントリー生命科学財団, 生物有機科学研究所, 研究員 (90353515) ; NISHIYAMA Ken-ichi 岩手大学, 農学部, 教授 (80291334)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 糖脂質 / 膜挿入 / 膜タンパク質 / 生体膜 / 糖鎖 / 固体NMR

Outline of Final Research Achievements

MPIase (Membrane Protein Integrase) is a glycolipid composed of diacylglycerol and a glycan chain of three acetylated aminosugars linked through pyrophosphate, and is essential for membrane protein integration. It is found that a physiological concentration of diacylglycerol (DAG) blocks the integration of proteins into membranes, whereas MPIase restores the integration. In this study, we characterized membranes composed of E. coli phospholipids in the presence and absence of DAG/MPIase by solid-state NMR experiments. We revealed that neither DAG nor MPIase changes lipid polymorphic phase and that DAG decreases the mobility of lipids while MPIase increases it. Based on these results, we deduced the mechanism of membrane protein integration by MPIase.

Free Research Field

生物有機化学