Nonequilibrium energetics of a single F1-ATPase molecule.
Molecular motors drive mechanical motions utilizing the free energy liberated from chemical reactions such as ATP hydrolysis. Although it is essential to know the efficiency of this free energy transduction, it has been a challenge due to the system's microscopic scale. Here, we evaluate the single-molecule energetics of a rotary molecular motor, F1-ATPase, by applying a recently derived nonequilibrium equality together with an electrorotation method. We show that the sum of the heat flow through the probe's rotational degree of freedom and the work against an external load is almost equal to the free energy change per a single ATP hydrolysis under various conditions. This implies that F1-ATPase works at an efficiency of nearly 100% in a thermally fluctuating environment.
Toyabe
Shoichi
S
Faculty of Science and Engineering, Chuo University, Tokyo 112-8551, Japan.
Okamoto
Tetsuaki
T
Watanabe-Nakayama
Takahiro
T
Taketani
Hiroshi
H
Kudo
Seishi
S
Muneyuki
Eiro
E
D001407:Bacillus / Q000201:enzymology; D004560:Electricity; D057075:Enzyme Assays / Q000379:methods*; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D006868:Hydrolysis; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000378:metabolism*; D012399:Rotation; D013816:Thermodynamics
D004800:Enzymes, Immobilized; D006180:Proton-Translocating ATPases