Skip to main content
NCBI home page
Biophysical Journal logoLink to Biophysical Journal
. 1983 Nov;44(2):145–151. doi: 10.1016/S0006-3495(83)84286-6

Kinetic model for the interaction of myosin subfragment 1 with regulated actin.

A C Balazs, I R Epstein
PMCID: PMC1434834  PMID: 6652210

Abstract

A one-dimensional kinetic Ising model is developed to describe the binding of myosin subfragment 1 (SF-1) to regulated actin. The model allows for cooperative interactions between individual actin sites with bound SF-1 ligands rather than assuming that groups of actin monomer sites change their state in a cooperative fashion. With the triplet closure approximation, the model yields a set of 16 independent differential (master) equations which may be solved numerically to yield the extent of binding as a function of time. The predictions of the model are compared with experiments on the transient binding of SF-1 to regulated actin in the presence of Ca2+ and in the absence of Ca2+ with varying amounts of SF-1 prebound to the actin filament and on the equilibrium binding of SF-1 X ADP to regulated actin in the absence of Ca2+. In all cases, the calculations fit the data to within the experimental errors. In the case of SF-1 X ADP, the results suggest that a repulsive interaction exists between adjacently bound SF-1 at the ends of two neighboring seven-site actin units.

Full text

PDF
145

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Chalovich J. M., Chock P. B., Eisenberg E. Mechanism of action of troponin . tropomyosin. Inhibition of actomyosin ATPase activity without inhibition of myosin binding to actin. J Biol Chem. 1981 Jan 25;256(2):575–578. [PMC free article] [PubMed] [Google Scholar]
  2. Ebashi S., Endo M., Otsuki I. Control of muscle contraction. Q Rev Biophys. 1969 Nov;2(4):351–384. doi: 10.1017/s0033583500001190. [DOI] [PubMed] [Google Scholar]
  3. Greene L. E., Eisenberg E. Cooperative binding of myosin subfragment-1 to the actin-troponin-tropomyosin complex. Proc Natl Acad Sci U S A. 1980 May;77(5):2616–2620. doi: 10.1073/pnas.77.5.2616. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Hill T. L. Binding under a molecular "umbrella" as a cooperative statistical mechanical system: tropomyosin-actin-myosin as an example. Biophys Chem. 1981 Sep;14(1):31–44. doi: 10.1016/0301-4622(81)87004-4. [DOI] [PubMed] [Google Scholar]
  5. Hill T. L., Eisenberg E., Greene L. Theoretical model for the cooperative equilibrium binding of myosin subfragment 1 to the actin-troponin-tropomyosin complex. Proc Natl Acad Sci U S A. 1980 Jun;77(6):3186–3190. doi: 10.1073/pnas.77.6.3186. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Lohman T. M., Kowalczykowski S. C. Kinetics and mechanism of the association of the bacteriophage T4 gene 32 (helix destabilizing) protein with single-stranded nucleic acids. Evidence for protein translocation. J Mol Biol. 1981 Oct 15;152(1):67–109. doi: 10.1016/0022-2836(81)90096-6. [DOI] [PubMed] [Google Scholar]
  7. Lohman T. M. Model for the irreversible dissociation kinetics of cooperatively bound protein-nucleic acid complexes. Biopolymers. 1983 Jul;22(7):1697–1713. doi: 10.1002/bip.360220707. [DOI] [PubMed] [Google Scholar]
  8. Loscalzo J., Reed G. H., Weber A. Conformational change and cooperativity in actin filaments free of tropomyosin. Proc Natl Acad Sci U S A. 1975 Sep;72(9):3412–3415. doi: 10.1073/pnas.72.9.3412. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. McGhee J. D., von Hippel P. H. Theoretical aspects of DNA-protein interactions: co-operative and non-co-operative binding of large ligands to a one-dimensional homogeneous lattice. J Mol Biol. 1974 Jun 25;86(2):469–489. doi: 10.1016/0022-2836(74)90031-x. [DOI] [PubMed] [Google Scholar]
  10. McLachlan A. D., Stewart M. The 14-fold periodicity in alpha-tropomyosin and the interaction with actin. J Mol Biol. 1976 May 15;103(2):271–298. doi: 10.1016/0022-2836(76)90313-2. [DOI] [PubMed] [Google Scholar]
  11. Nagashima H., Asakura S. Studies on co-operative properties of tropomyosin-actin and tropomyosin-troponin-actin complexes by the use of N-ethylmaleimide-treated and untreated species of myosin subfragment 1. J Mol Biol. 1982 Mar 15;155(4):409–428. doi: 10.1016/0022-2836(82)90479-x. [DOI] [PubMed] [Google Scholar]
  12. Parry D. A., Squire J. M. Structural role of tropomyosin in muscle regulation: analysis of the x-ray diffraction patterns from relaxed and contracting muscles. J Mol Biol. 1973 Mar 25;75(1):33–55. doi: 10.1016/0022-2836(73)90527-5. [DOI] [PubMed] [Google Scholar]
  13. Phillips G. N., Jr, Lattman E. E., Cummins P., Lee K. Y., Cohen C. Crystal structure and molecular interactions of tropomyosin. Nature. 1979 Mar 29;278(5703):413–417. doi: 10.1038/278413a0. [DOI] [PubMed] [Google Scholar]
  14. SCHWARZ G. ON THE KINETICS OF THE HELIX-COIL TRANSITION OF POLYPEPTIDES IN SOLUTION. J Mol Biol. 1965 Jan;11:64–77. doi: 10.1016/s0022-2836(65)80171-1. [DOI] [PubMed] [Google Scholar]
  15. Trybus K. M., Taylor E. W. Kinetic studies of the cooperative binding of subfragment 1 to regulated actin. Proc Natl Acad Sci U S A. 1980 Dec;77(12):7209–7213. doi: 10.1073/pnas.77.12.7209. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Biophysical Journal are provided here courtesy of The Biophysical Society

RESOURCES