Depth-dependent melting of acyl chains and phase-transition of lipid bilayers

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K13100
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Chemical biology
• Research Institution: Osaka University
• Principal Investigator: Murata Michio 大阪大学, 理学研究科, 教授 (40183652)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 脂質二重膜 / 相転移温度 / スフィンゴミエリン / フォスファチジルコリン / 重水素NMR / 赤外分光スペクトル

Outline of Final Research Achievements

Four kinds of deuterium-substituted fatty acids were chemically synthesized to prepare 2H-labeled sphingomyelin (SM) as a raft lipid and phosphatidylcholine (PC) as a control lipid. The results of 2H NMR and IR spectra of the labeled SM bilayer indicated that the melting temperature (mp) is depth-dependent with a lower mp for the terminal part of acyl chains while the melting of PC is less depth-dependent. Also, a clear melting point disappeared by an addition of cholesterol for both SM and PC membranes while the conformational change of SM terminal chains observed in IR spectra may account for the difference in the depth dependent melting of SM as compared with PC.

Free Research Field

生物有機化学