Molecular mechanisms in a visual transduction system of invertebrate rhodopsin

2015 Fiscal Year Final Research Report

• Project/Area Number: 24370043
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Structural biochemistry
• Research Institution: Nagoya University
• Principal Investigator: Murakami Midori 名古屋大学, 理学(系)研究科(研究院), 助教 (20324387)
• Co-Investigator(Kenkyū-buntansha): Kouyama Tsutomu 名古屋大学, 大学院理学研究科, 教授 (30170210)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: ロドプシン / 光情報変換 / 結晶構造解析

Outline of Final Research Achievements

Blue light illumination at 100 K induced a red-shift of the absorption maximum, indicating that an equilibrium state of three isomeric states, Rhodopsin, Batho and 9-cis isorhodopsin was established. When this crystal was warmed to 240K, the absorption maximum was blue-shifted. Accurate estimation of isomer composition under this condition suggested that Batho was converted to LM with no change in the contents of the other states. We collected diffraction data set and calculate the difference electron density maps. It indicates that the conformational changes are located at the vicinity of the active site upon formation the LM intermediate. The larger movements of helices that characterize meta formation are not initiated at the early stage of photocycle in squid rhodopsin, but occur during the transition from LM to Meta. We try to crystallize the Acid Meta state of squid rhodopsin and succeed to obtain some new crystals which can diffract up to high resolution.

Free Research Field

生物物理