Fluctuation analysis of mechanochemical coupling depending on the type of biomolecular motors.
Mechanochemical coupling was studied for myosin II and V consistently. The fluctuation in myosin V motility was determined by correlating the stochasticity of the ATPase reaction with regular displacements per one ATP, consistent with a tight mechanochemical coupling. In contrast, myosin II, working in an ensemble, was explained by a loose coupling, generating variable step sizes which depend on [ATP] and realizing a much larger step (200 nm) per one ATP than myosin V through its cooperativity at zero load. These different mechanics are ideal for their physiological functions.
Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan. masnishi@hiroshima-u.ac.jp
Masatoshi
M
Nishikawa
Hiroaki
H
Takagi
Tatsuo
T
Shibata
Atsuko H
AH
Iwane
Toshio
T
Yanagida
D008841:Actin Cytoskeleton / Q000737:chemistry; D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D001696:Biomechanical Phenomena; D005456:Fluorescent Dyes / Q000737:chemistry; D007700:Kinetics; D008958:Models, Molecular; D020409:Molecular Motor Proteins / Q000737:chemistry / Q000378:metabolism; D024462:Myosin Type II / Q000737:chemistry* / Q000378:metabolism; D024701:Myosin Type V / Q000737:chemistry* / Q000378:metabolism
D005456:Fluorescent Dyes; D020409:Molecular Motor Proteins; D000255:Adenosine Triphosphate; D024462:Myosin Type II; D024701:Myosin Type V