Biophysical Journal 70: 637-653 (1996)
© 1996 the Biophysical Society

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Astumian, R D Articles by Bier, M Search for Related Content PubMed PubMed Citation Articles by Astumian, R D Articles by Bier, M

Mechanochemical coupling of the motion of molecular motors to ATP hydrolysis.

Department of Surgery, University of Chicago, Illinois 60637, USA. dean@kramers.bsd.uchicago.edu

ABSTRACT

The typical biochemical paradigm for coupling between hydrolysis of ATP and the performance of chemical or mechanical work involves a well-defined sequence of events (a kinetic mechanism) with a fixed stoichiometry between the number of ATP molecules hydrolyzed and the turnover of the output reaction. Recent experiments show, however, that such a deterministic picture of coupling may not be adequate to explain observed behavior of molecular motor proteins in the presence of applied forces. Here we present a general model in which the binding of ATP and release of ADP serve to modulate the binding energy of a motor protein as it travels along a biopolymer backbone. The mechanism is loosely coupled--the average number of ATPs hydrolyzed to cause a single step from one binding site to the next depends strongly on the magnitude of an applied force and on the effective viscous drag force. The statistical mechanical perspective described here offers insight into how local anisotrophy along the "track" for a molecular motor, combined with an energy-releasing chemical reaction to provide a source of nonequilibrium fluctuations, can lead to macroscopic motion.

This article has been cited by other articles:

				E. Muneyuki, C. Shibazaki, Y. Wada, M. Yakushizin, and H. Ohtani Cl- Concentration Dependence of Photovoltage Generation by Halorhodopsin from Halobacterium salinarum Biophys. J., October 1, 2002; 83(4): 1749 - 1759. [Abstract] [Full Text] [PDF]

				E. W. Taylor and G. G. Borisy Kinesin Processivity J. Cell Biol., November 20, 2000; 151(5): F27 - F30. [Abstract] [Full Text] [PDF]

				J. S. Bader, R. W. Hammond, S. A. Henck, M. W. Deem, G. A. McDermott, J. M. Bustillo, J. W. Simpson, G. T. Mulhern, and J. M. Rothberg DNA transport by a micromachined Brownian ratchet device PNAS, November 9, 1999; 96(23): 13165 - 13169. [Abstract] [Full Text] [PDF]

				D. L. Coy, M. Wagenbach, and J. Howard Kinesin Takes One 8-nm Step for Each ATP That It Hydrolyzes J. Biol. Chem., February 5, 1999; 274(6): 3667 - 3671. [Abstract] [Full Text] [PDF]

				M. B. Tarlie and R. D. Astumian Optimal modulation of a Brownian ratchet and enhanced sensitivity to a weak external force PNAS, March 3, 1998; 95(5): 2039 - 2043. [Abstract] [Full Text] [PDF]

				C Huber, R Saffrich, M Anton, M Passreiter, W Ansorge, K Gorgas, and W Just A heterotrimeric G protein-phospholipase A2 signaling cascade is involved in the regulation of peroxisomal motility in CHO cells J. Cell Sci., January 12, 1997; 110(23): 2955 - 2968. [Abstract] [PDF]