Journal article
BDM affects nucleotide binding and force generation steps of the cross-bridge cycle in rabbit psoas muscle fibers
American Journal of Physiology: Cell Physiology, Vol.266(2), pp.C437-C447
02/01/1994
DOI: 10.1152/ajpcell.1994.266.2.C437
PMID: 8141258
Abstract
The effect of 2,3-butanedione monoxime (BDM) on elementary steps of the cross-bridge cycle was studied with the sinusoidal analysis technique in skinned rabbit psoas muscle fibers. Our results showed that isometric tension and stiffness decreased progressively with an increase in the BDM concentration. The MgATP and MgADP binding constants increased 27 and 6 times, respectively, when BDM was increased from 0 to 18 mM, whereas the phosphate binding constant did not change significantly. The equilibrium constants of the ATP isomerization and detachment step were not sensitive to BDM, whereas the equilibrium constant of the attachment (power stroke) step decreased with BDM. Thus, in the presence of BDM, the number of attached cross bridges decreases; more cross bridges accumulate in the detached state, causing isometric tension and stiffness to decline. However, our detailed analysis shows that the decrease in the number of attached cross bridges is approximately 40%, which is not adequate to account for the 84% decrease in the isometric tension when 18 mM BDM was present. Therefore we suggest that a thin-filament activation mechanism is also affected by BDM.
Details
- Title: Subtitle
- BDM affects nucleotide binding and force generation steps of the cross-bridge cycle in rabbit psoas muscle fibers
- Creators
- Y Zhao - Department of Anatomy, College of Medicine, University of Iowa, IowaCity 52242M Kawai - Department of Anatomy, College of Medicine, University of Iowa, IowaCity 52242
- Resource Type
- Journal article
- Publication Details
- American Journal of Physiology: Cell Physiology, Vol.266(2), pp.C437-C447
- DOI
- 10.1152/ajpcell.1994.266.2.C437
- PMID
- 8141258
- ISSN
- 0363-6143
- eISSN
- 1522-1563
- Language
- English
- Date published
- 02/01/1994
- Academic Unit
- Anatomy and Cell Biology; Internal Medicine
- Record Identifier
- 9984025329202771
Metrics
20 Record Views