Journal article
EFFECT OF MGATP ON STIFFNESS MEASURED AT 2 FREQUENCIES IN CA2+-ACTIVATED MUSCLE-FIBERS - (CROSS-BRIDGE-TENSION RATE CONSTANT RIGOR SUBSTRATE)
Proceedings of the National Academy of Sciences - PNAS, Vol.74(9), pp.4073-4075
01/01/1977
DOI: 10.1073/pnas.74.9.4073
PMCID: PMC431850
PMID: 269452
Abstract
The stiffness of skinned crayfish single muscle fibers was continuously monitored at two frequencies. The length of the fibers was oscillated by the sum of two sine waves (5 Hz and 100 Hz) of small amplitudes. In saline containing saturating amounts of Ca2+, the stiffness ratio (5 Hz:100 Hz) was constant as the MgATP (substrate) concentration was raised from 0 to 2 μM, then it decreased with a further increment in MgATP. The systematic decrease in the stiffness ratio in MgATP above 2 μM indicates the presence of faster transitions in the cross-bridge cycle. This dependence of the stiffness ratio on MgATP is predictable if we use the two-state model of A.F. Huxley (1957) with a modification, in which MgATP promotes the dissociation of the attached cross-bridges.
Details
- Title: Subtitle
- EFFECT OF MGATP ON STIFFNESS MEASURED AT 2 FREQUENCIES IN CA2+-ACTIVATED MUSCLE-FIBERS - (CROSS-BRIDGE-TENSION RATE CONSTANT RIGOR SUBSTRATE)
- Creators
- M KawaiP W Brandt
- Resource Type
- Journal article
- Publication Details
- Proceedings of the National Academy of Sciences - PNAS, Vol.74(9), pp.4073-4075
- DOI
- 10.1073/pnas.74.9.4073
- PMID
- 269452
- PMCID
- PMC431850
- NLM abbreviation
- Proc Natl Acad Sci U S A
- ISSN
- 0027-8424
- eISSN
- 1091-6490
- Publisher
- National Academy of Sciences
- Number of pages
- 3
- Language
- English
- Date published
- 01/01/1977
- Academic Unit
- Anatomy and Cell Biology; Internal Medicine
- Record Identifier
- 9984284459002771
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