Dynamics of single-motor molecules: the thermal ratchet model.
AUTOR(ES)
Córdova, N J
RESUMO
We present a model for single-motor molecules--myosin, dynein, or kinesin--that is powered either by thermal fluctuations or by conformational change. In the thermally driven model, the cross-bridge fluctuates about its equilibrium position against an elastic restoring force. The attachment and detachment of the cross-bridge are determined by modeling the electrostatic attraction between the cross-bridge and the fiber binding sites, so that binding depends on the strain in the cross-bridge and its velocity with respect to the fiber. The model correctly predicts the empirical force-velocity characteristics for populations of motor molecules. For a single motor, the apparent cross-bridge step size per ATP hydrolysis depends nonlinearly on the load. When the elastic energy driving the cross-bridge is generated by a conformational change, the velocity and duty cycle are much larger than is observed experimentally for myosin.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=48232Documentos Relacionados
- Gap junction modulation by extracellular signaling molecules: the thymus model
- Sorting single molecules: application to diagnostics and evolutionary biotechnology.
- Dynamics of unbinding of cell adhesion molecules: Transition from catch to slip bonds
- The role of charge and multiple faces of the CD8 alpha/alpha homodimer in binding to major histocompatibility complex class I molecules: support for a bivalent model.
- Probing the interaction between two single molecules: fluorescence resonance energy transfer between a single donor and a single acceptor.