Theoretical model for the cooperative equilibrium binding of myosin subfragment 1 to the actin-troponin-tropomyosin complex.
Recent experimental data on the equilibrium binding of myosin subfragment 1 ( S-1) to regulated actin filaments in the presence and in the absence of Ca(2+) are analyzed by using a linear Ising model. In the model, each tropomyosin-troponin unit (including seven sites on the actin filament) can be in one of two possible states, which have different intrinsic free energies and different binding constants for S-1. Bound S-1 molecules do not interact with each other. There are nearest-neighbor (pair) interactions between these units that depend on the state of each member of the pair and on the number of Ca(2+) bound to one member of the pair. There are two sources of positive cooperativity in this system: the fact that seven actin sites change state together as part of a single unit; and the existence of attractive nearest-neighbor interactions between units. Parameters in the model are evaluated by fitting the data, both in the presence and in the absence of Ca(2+). Several extensions of this model are discussed.[1]References
- Theoretical model for the cooperative equilibrium binding of myosin subfragment 1 to the actin-troponin-tropomyosin complex. Hill, T.L., Eisenberg, E., Greene, L. Proc. Natl. Acad. Sci. U.S.A. (1980) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
