Journal article
Molecular forces involved in force generation during skeletal muscle contraction
Journal of experimental biology, Vol.199(Pt 12), pp.2565-2571
12/1996
DOI: 10.1242/jeb.199.12.2565
PMID: 9110950
Abstract
Recent advances in protein chemistry and the kinetic analysis of tension transients in skeletal muscle fibres have enabled us to elucidate the molecular forces involved in force generation by cross-bridges. On the basis of the temperature effect, we conclude that the elementary step that generates force is an endothermic reaction (the enthalpy change delta H degree = 124 kJ mol-1 at 15 degrees C), which accompanies a large entropy increase (delta S degree = 430JK-1 mol-1) and a reduction in the heat capacity (delta C p = -6.4kJ K-1 mol-1). Thus, it can be concluded that the force-generating step is an entropy-driven reaction. The above results suggest that hydrophobic interactions are the primary cause of force generation, and that polar interactions (hydrogen bonding and charge interactions) are involved to a lesser degree. On the basis of the thermodynamic data, we estimate that during force generation approximately 50 nm2 of surface area is involved for hydrophobic interactions and another 30 nm2 for polar interactions. These data suggest that both the actomyosin interaction and the cleft closure of the myosin head are essential for force generation.
Details
- Title: Subtitle
- Molecular forces involved in force generation during skeletal muscle contraction
- Creators
- K P Murphy - University of IowaY Zhao - University of IowaM Kawai - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Journal of experimental biology, Vol.199(Pt 12), pp.2565-2571
- DOI
- 10.1242/jeb.199.12.2565
- PMID
- 9110950
- ISSN
- 0022-0949
- eISSN
- 1477-9145
- Language
- English
- Date published
- 12/1996
- Academic Unit
- Anatomy and Cell Biology; Internal Medicine
- Record Identifier
- 9984284332002771
Metrics
8 Record Views