Effect of Ca binding properties of troponin C on rate of skeletal muscle force redevelopment
نویسندگان
چکیده
Ryan S. Lee,* Svetlana B. Tikunova,* Kristopher P. Kline, Henry G. Zot, Javier E. Hasbun, Nguyen Van Minh, Darl R. Swartz, Jack A. Rall, and Jonathan P. Davis Department of Physiology and Cell Biology, Ohio State University, Columbus, Ohio; Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Houston, Texas; Department of Biology, University of West Georgia, Carrollton, Georgia; and Department of Animal Sciences, Purdue University, West Lafayette, Indiana
منابع مشابه
Effect of Ca2+ binding properties of troponin C on rate of skeletal muscle force redevelopment.
To investigate effects of altering troponin (Tn)C Ca(2+) binding properties on rate of skeletal muscle contraction, we generated three mutant TnCs with increased or decreased Ca(2+) sensitivities. Ca(2+) binding properties of the regulatory domain of TnC within the Tn complex were characterized by following the fluorescence of an IAANS probe attached onto the endogenous Cys(99) residue of TnC. ...
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Regulation of contraction in skeletal muscle is a highly cooperative process involving Ca(2+) binding to troponin C (TnC) and strong binding of myosin cross-bridges to actin. To further investigate the role(s) of cooperation in activating the kinetics of cross-bridge cycling, we measured the Ca(2+) dependence of the rate constant of force redevelopment (k(tr)) in skinned single fibers in which ...
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In striated muscle thin filament activation is initiated by Ca(2+) binding to troponin C and augmented by strong myosin binding to actin (cross-bridge formation). Several lines of evidence have led us to hypothesize that thin filament properties may limit the level and rate of force development in cardiac muscle at all levels of Ca(2+) activation. As a test of this hypothesis we varied the cros...
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We investigated whether changing thin filament Ca(2+) sensitivity alters the rate of contraction, either during normal cross-bridge cycling or when cross-bridge cycling is increased by inorganic phosphate (P(i)). We increased or decreased Ca(2+) sensitivity of force production by incorporating into rat skinned cardiac trabeculae the troponin C (TnC) mutants V44QTnC(F27W) and F20QTnC(F27W). The ...
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The effects of dissociation of force-generating cross bridges on intracellular Ca(2+), pCa-force, and pCa-ATPase relationships were investigated in mouse skeletal muscle. Mechanical length perturbations were used to dissociate force-generating cross bridges in either intact or skinned fibers. In intact muscle, an impulse stretch or release, a continuous length vibration, a nonoverlap stretch, o...
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