Journal article
Covalent cross-linking of single fibers from rabbit psoas increases oscillatory power
Biophysical journal, Vol.57(3), pp.643-647
03/1990
DOI: 10.1016/S0006-3495(90)82582-0
PMCID: PMC1280760
PMID: 2306508
Abstract
Single fibers from chemically skinned rabbit psoas muscle were treated with 1-ethyl-3-[3-dimethyl-amino)proyl]-carbodiimide (EDC) at 20 degrees C after rigor was induced. A 22-min treatment resulted in 18% covalent cross-linking between myosin heads and the thin filament as determined by stiffness measurements. This treatment also results in covalent cross-linking among rod portions of myosin molecules in the backbone of the thick filament. The fibers thus prepared are stable and do not dissolve in solutions at ionic strengths as high as 1,000 mM. The preparation was subjected to sinusoidal analysis, and the resulting complex modulus data were analyzed in terms of three exponential processes, (A), (B), and (C). Oscillatory work (process B) was much greater in the cross-linked fibers than in untreated ones in activating solutions of physiological ionic strength (200 mM); this difference was attributed to the decline of process (A) with EDC treatment. Consequently, the Nyquist plot of the EDC-treated preparation exhibited an insect-type response. We conclude that, under these conditions, both cross-linked and non-cross-linked myosin heads contribute to the production of oscillatory power. The cross-linked preparations also exhibited oscillatory work in high ionic strength (500-1,000 mM) solutions, indicating that cross-linked myosin heads are capable of utilizing ATP to produce work. We conclude that process (A) does not relate to an elementary step in a cross-bridge cycle, but it may relate to dynamics outside the cross-bridge such as filament sliding or sarcomere rearrangement.
Details
- Title: Subtitle
- Covalent cross-linking of single fibers from rabbit psoas increases oscillatory power
- Creators
- K Tawada - Department of Biology, Faculty of Science, Kyushu University, Fukuoka, JapanM Kawai - Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
- Resource Type
- Journal article
- Publication Details
- Biophysical journal, Vol.57(3), pp.643-647
- DOI
- 10.1016/S0006-3495(90)82582-0
- PMID
- 2306508
- PMCID
- PMC1280760
- NLM abbreviation
- Biophys J
- ISSN
- 0006-3495
- eISSN
- 1542-0086
- Language
- English
- Date published
- 03/1990
- Academic Unit
- Anatomy and Cell Biology; Internal Medicine
- Record Identifier
- 9984025325302771
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