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Remarks on Muscle Contraction Mechanism II. Isometric Tension Transient and Isotonic Velocity Transient

Mitsui and Ohshima (2008) criticized the power-stroke model for muscle contraction and proposed a new model. In the new model, about 41% of the myosin heads are bound to actin filaments, and each bound head forms a complex MA(3) with three actin molecules A1, A2 and A3 forming the crossbridge. The c...

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Autores principales: Mitsui, Toshio, Takai, Nobukatsu, Ohshima, Hiroyuki
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Molecular Diversity Preservation International (MDPI) 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3111628/
https://www.ncbi.nlm.nih.gov/pubmed/21673917
http://dx.doi.org/10.3390/ijms12031697
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author Mitsui, Toshio
Takai, Nobukatsu
Ohshima, Hiroyuki
author_facet Mitsui, Toshio
Takai, Nobukatsu
Ohshima, Hiroyuki
author_sort Mitsui, Toshio
collection PubMed
description Mitsui and Ohshima (2008) criticized the power-stroke model for muscle contraction and proposed a new model. In the new model, about 41% of the myosin heads are bound to actin filaments, and each bound head forms a complex MA(3) with three actin molecules A1, A2 and A3 forming the crossbridge. The complex translates along the actin filament cooperating with each other. The new model well explained the experimental data on the steady filament sliding. As an extension of the study, the isometric tension transient and isotonic velocity transient are investigated. Statistical ensemble of crossbridges is introduced, and variation of the binding probability of myosin head to A1 is considered. When the binding probability to A1 is zero, the Hill-type force-velocity relation is resulted in. When the binding probability to A1 becomes finite, the deviation from the Hill-type force-velocity relation takes place, as observed by Edman (1988). The characteristics of the isometric tension transient observed by Ford, Huxley and Simmons (1977) and of the isotonic velocity transient observed by Civan and Podolsky (1966) are theoretically reproduced. Ratios of the extensibility are estimated as 0.22 for the crossbridge, 0.26 for the myosin filament and 0.52 for the actin filament, in consistency with the values determined by X-ray diffraction by Wakabayashi et al. (1994).
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spelling pubmed-31116282011-06-13 Remarks on Muscle Contraction Mechanism II. Isometric Tension Transient and Isotonic Velocity Transient Mitsui, Toshio Takai, Nobukatsu Ohshima, Hiroyuki Int J Mol Sci Article Mitsui and Ohshima (2008) criticized the power-stroke model for muscle contraction and proposed a new model. In the new model, about 41% of the myosin heads are bound to actin filaments, and each bound head forms a complex MA(3) with three actin molecules A1, A2 and A3 forming the crossbridge. The complex translates along the actin filament cooperating with each other. The new model well explained the experimental data on the steady filament sliding. As an extension of the study, the isometric tension transient and isotonic velocity transient are investigated. Statistical ensemble of crossbridges is introduced, and variation of the binding probability of myosin head to A1 is considered. When the binding probability to A1 is zero, the Hill-type force-velocity relation is resulted in. When the binding probability to A1 becomes finite, the deviation from the Hill-type force-velocity relation takes place, as observed by Edman (1988). The characteristics of the isometric tension transient observed by Ford, Huxley and Simmons (1977) and of the isotonic velocity transient observed by Civan and Podolsky (1966) are theoretically reproduced. Ratios of the extensibility are estimated as 0.22 for the crossbridge, 0.26 for the myosin filament and 0.52 for the actin filament, in consistency with the values determined by X-ray diffraction by Wakabayashi et al. (1994). Molecular Diversity Preservation International (MDPI) 2011-03-04 /pmc/articles/PMC3111628/ /pubmed/21673917 http://dx.doi.org/10.3390/ijms12031697 Text en © 2011 by the authors; licensee MDPI, Basel, Switzerland. http://creativecommons.org/licenses/by/3.0 This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).
spellingShingle Article
Mitsui, Toshio
Takai, Nobukatsu
Ohshima, Hiroyuki
Remarks on Muscle Contraction Mechanism II. Isometric Tension Transient and Isotonic Velocity Transient
title Remarks on Muscle Contraction Mechanism II. Isometric Tension Transient and Isotonic Velocity Transient
title_full Remarks on Muscle Contraction Mechanism II. Isometric Tension Transient and Isotonic Velocity Transient
title_fullStr Remarks on Muscle Contraction Mechanism II. Isometric Tension Transient and Isotonic Velocity Transient
title_full_unstemmed Remarks on Muscle Contraction Mechanism II. Isometric Tension Transient and Isotonic Velocity Transient
title_short Remarks on Muscle Contraction Mechanism II. Isometric Tension Transient and Isotonic Velocity Transient
title_sort remarks on muscle contraction mechanism ii. isometric tension transient and isotonic velocity transient
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3111628/
https://www.ncbi.nlm.nih.gov/pubmed/21673917
http://dx.doi.org/10.3390/ijms12031697
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