The role of three-state docking of myosin S1 with actin in force generation.

@article{citeulike:1942515, abstract = {It has been shown that in solution myosin subfragment 1 binds to actin in three principal steps: [formula: see text] The nucleotide bound to myosin has a major influence on the equilibrium constant of the third of these steps but little effect on the other two. The third step is thought to be coupled to the force-generating event. Three-step binding and structure: The formation of the collision complex is strongly ionic strength dependent but independent of temperature. The isomerization to the A state is not strongly dependent on ionic strength but is affected by organic solvent and temperature. In contrast the isomerization to the R state-is affected by both ionic strength and organic solvent but little affected by temperature. The recent docking of the three-dimensional structures of actin and S1 suggest possible structural correlates of these events. These studies lead to predictions for the docking process, which may be tested using site-directed mutagenesis or peptide inhibitors. Three-step binding and head-head interactions: Studies of HMM binding to actin compared with S1 binding show that binding of two heads in the A state are unlikely presumably because of strain effects. However, binding of two heads as one A and one R state shows little evidence of strain while the isomerization of the second head to give two R states is fivefold weaker than for an isolated S1 head. These results suggest that in a rapidly shortening muscle only one head is likely to be attached at a time.(ABSTRACT TRUNCATED AT 250 WORDS)}, address = {Max Planck Institute for Molecular Physiology, Dortmund, Germany.}, author = {Geeves, M. A. and Conibear, P. B. }, citeulike-article-id = {1942515}, issn = {0006-3495}, journal = {Biophys J}, keywords = {experiment, isomerize, kinetics, myosin}, month = {April}, number = {4 Suppl}, posted-at = {2007-11-20 09:30:16}, priority = {2}, title = {The role of three-state docking of myosin S1 with actin in force generation.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/7787067}, volume = {68}, year = {1995} }

TY - JOUR ID - citeulike:1942515 L3 - citeulike-article-id:1942515 TI - The role of three-state docking of myosin S1 with actin in force generation. JF - Biophys J VL - 68 IS - 4 Suppl AD - Max Planck Institute for Molecular Physiology, Dortmund, Germany. SN - 0006-3495 N2 - It has been shown that in solution myosin subfragment 1 binds to actin in three principal steps: [formula: see text] The nucleotide bound to myosin has a major influence on the equilibrium constant of the third of these steps but little effect on the other two. The third step is thought to be coupled to the force-generating event. Three-step binding and structure: The formation of the collision complex is strongly ionic strength dependent but independent of temperature. The isomerization to the A state is not strongly dependent on ionic strength but is affected by organic solvent and temperature. In contrast the isomerization to the R state-is affected by both ionic strength and organic solvent but little affected by temperature. The recent docking of the three-dimensional structures of actin and S1 suggest possible structural correlates of these events. These studies lead to predictions for the docking process, which may be tested using site-directed mutagenesis or peptide inhibitors. Three-step binding and head-head interactions: Studies of HMM binding to actin compared with S1 binding show that binding of two heads in the A state are unlikely presumably because of strain effects. However, binding of two heads as one A and one R state shows little evidence of strain while the isomerization of the second head to give two R states is fivefold weaker than for an isolated S1 head. These results suggest that in a rapidly shortening muscle only one head is likely to be attached at a time.(ABSTRACT TRUNCATED AT 250 WORDS) KW - experiment KW - isomerize KW - kinetics KW - myosin AU - Geeves, MA AU - Conibear, PB PY - 1995/04// UR - http://view.ncbi.nlm.nih.gov/pubmed/7787067 ER -