Driving myosin by polymorphism and hydration-state control of actin filaments

2016 Fiscal Year Final Research Report

• Project/Area Number: 16K13860
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Biological physics/Chemical physics/Soft matter physics
• Research Institution: Tohoku University
• Principal Investigator: Suzuki Makoto 東北大学, 工学研究科, 教授 (60282109)
• Co-Investigator(Renkei-kenkyūsha): MATUBAYASI Nobuyuki 大阪大学, 大学院基礎工学研究科, 教授 (20281107) ; KINOSHITA Masahiro 京都大学, エネルギー理工学研究所, 教授 (90195339) ; IWAKI Mitsuhiro 理化学研究所, 生命システム研究センター, 上級研究員 (30432503)
• Research Collaborator: YAMAGUCHI Takaya 東北大学, 大学院工学研究科
• Project Period (FY): 2016-04-01 – 2017-03-31
• Keywords: actomyosin / ATP energy / hydration free energy / driving force / hydration control / water entropy / polymorphism / Ca ion control

Outline of Final Research Achievements

In this study, we carried out an experiment to examine whether F-actin could be driven on a myosin-coated substrate by controlling the hydration state change of actomyosin complex without using ATP hydrolysis. Firstly, by CD spectroscopy, it was confirmed that the secondary and tertiary structures of F-actin were controlled by changing Mg(2+) and Ca(2+) concentrations using EGTA. Secondly, as the initial weak-binding state, acto-myosin (heavy meromyosin) complex with AMPPNP at relatively low ionic condition was formed. When the Ca2+ concentration was increased by using caged-Ca and irradiation of UV light, we observed ~60 nm displacement of a Q-dot attached on F-actin. Further experiments must be made to confirm this observation and to establish this new driving principle.

Free Research Field

生物物理