A kinetic model describing the processivity of myosin-V

被引:27
作者
Skau, Karl I.
Hoyle, Rebecca B.
Turner, Matthew S. [1 ]
机构
[1] Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England
[2] Univ Surrey, Dept Math, Guildford GU2 5XH, Surrey, England
基金
英国工程与自然科学研究理事会;
关键词
D O I
10.1529/biophysj.105.070888
中图分类号
Q6 [生物物理学];
学科分类号
071011 ;
摘要
The precise details of how myosin-V coordinates the biochemical reactions and mechanical motions of its two head elements to engineer effective processive molecular motion along actin. laments remain unresolved. We compare a quantitative kinetic model of the myosin-V walk, consisting of five basic states augmented by two further states to allow for futile hydrolysis and detachments, with experimental results for run lengths, velocities, and dwell times and their dependence on bulk nucleotide concentrations and external loads in both directions. The model reveals how myosin-V can use the internal strain in the molecule to synchronize the motion of the head elements. Estimates for the rate constants in the reaction cycle and the internal strain energy are obtained by a computational comparison scheme involving an extensive exploration of the large parameter space. This scheme exploits the fact that we have obtained analytic results for our reaction network, e. g., for the velocity but also the run length, diffusion constant, and fraction of backward steps. The agreement with experiment is often reasonable but some open problems are highlighted, in particular the inability of such a general model to reproduce the reported dependence of run length on ADP concentration. The novel way that our approach explores parameter space means that any confirmed discrepancies should give new insights into the reaction network model.
引用
收藏
页码:2475 / 2489
页数:15
相关论文
共 53 条
[11]   The kinetic mechanism of myosin V [J].
De La Cruz, EM ;
Wells, AL ;
Rosenfeld, SS ;
Ostap, EM ;
Sweeney, HL .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1999, 96 (24) :13726-13731
[12]   Relating biochemistry and function in the myosin superfamily [J].
De La Cruz, EM ;
Ostap, EM .
CURRENT OPINION IN CELL BIOLOGY, 2004, 16 (01) :61-67
[13]   Kinetic mechanism and regulation of myosin VI [J].
De la Cruz, EM ;
Ostap, EM ;
Sweeney, HL .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2001, 276 (34) :32373-32381
[14]   VELOCITY AND DIFFUSION CONSTANT OF A PERIODIC ONE-DIMENSIONAL HOPPING MODEL [J].
DERRIDA, B .
JOURNAL OF STATISTICAL PHYSICS, 1983, 31 (03) :433-450
[15]   Kinesin crouches to sprint but resists pushing [J].
Fisher, ME ;
Kim, YC .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2005, 102 (45) :16209-16214
[16]   Molecular motors and the forces they exert [J].
Fisher, ME ;
Kolomeisky, AB .
PHYSICA A, 1999, 274 (1-2) :241-266
[17]   Three-dimensional structural dynamics of myosin V by single-molecule fluorescence polarization [J].
Forkey, JN ;
Quinlan, ME ;
Shaw, MA ;
Corrie, JET ;
Goldman, YE .
NATURE, 2003, 422 (6930) :399-404
[18]  
Galassi M., 2003, GNU SCI LIB REFERENC
[19]   Structural mechanism of muscle contraction [J].
Geeves, MA ;
Holmes, KC .
ANNUAL REVIEW OF BIOCHEMISTRY, 1999, 68 :687-728
[20]   KINETICS OF ACTO-S1 INTERACTION AS A GUIDE TO A MODEL FOR THE CROSSBRIDGE CYCLE [J].
GEEVES, MA ;
GOODY, RS ;
GUTFREUND, H .
JOURNAL OF MUSCLE RESEARCH AND CELL MOTILITY, 1984, 5 (04) :351-361