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arXiv · 0801.1392

Fluctuation analysis of mechanochemical coupling depending on the type of bio-molecular motor

Masatoshi Nishikawa·Hiroaki Takagi·Atsuko H. Iwane·Toshio Yanagida
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Abstract

Mechanochemical coupling was studied for two different types of myosin motors in cells: myosin V, which carries cargo over long distances by as a single molecule; and myosin II, which generates a contracting force in cooperation with other myosin II molecules. Both mean and variance of myosin V velocity at various [ATP] obeyed Michaelis-Menten mechanics, consistent with tight mechanochemical coupling. Myosin II, working in an ensemble, however, was explained by a loose coupling mechanism, generating variable step sizes depending on the ATP concentration and realizing a much larger step (200 nm) per ATP hydrolysis than myosin V through its cooperative nature at zero load. These different mechanics are ideal for the respective myosin's physiological functions.

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Masatoshi Nishikawa, Hiroaki Takagi, Atsuko H. Iwane, Toshio Yanagida. 2008-01-09. Fluctuation analysis of mechanochemical coupling depending on the type of bio-molecular motor. https://doi.org/10.1103/physrevlett.101.128103

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