Mechanism underlying the clustering-dispersion dynamics of the channel protein on the membrane

2016 Fiscal Year Final Research Report

• Project/Area Number: 26253014
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: General physiology
• Research Institution: University of Fukui
• Principal Investigator: Oiki Shigetoshi 福井大学, 学術研究院医学系部門, 教授 (10185176)
• Co-Investigator(Kenkyū-buntansha): 炭竈 享司 福井大学, 医学部, 特命助教 (30579412) ; 岩本 真幸 福井大学, 医学部, 助教 (40452122) ; 角野 歩 福井大学, 医学部, 特別研究員 (80717140)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: lipid bilayer / single-channel current / membrane lipid / clustering / channel gating

Outline of Final Research Achievements

We found that the KcsA potassium channel move randomly on the membrane surface, and undergo clustering and dispersion in relation to the activation gating using the atomic force microscopy. To elucidate the underlying mechanism, we developed the method such that the channel was reconstituted into the membrane with the same orientation. Nearly 100% of the channels were oriented with their extracellular side up in the membrane. This orientation was confirmed by a scorpion toxin, agitoxin 2, using AFM. The clustering-dispersion status on the membrane was examined using the AFM in different lipid compositions, and the distribution was highly related to the phase separation of the membrane. On the other hand, the channel activities were measured using a newly developed contact bubble bilayer method, which allows varying the lipid composition of the membrane in each leaflet. We have screened various types of hydrophobic substances via the positive effects to the KcsA channel.

Free Research Field

生理学一般