A Method to Exchange Recombinant Differentially Phosphorylated Rhodamine-Labeled Cardiac RLC into Permeabilized Cardiac Trabeculae

Abstract

Phosphorylation of the myosin regulatory light chain (RLC) may be important for regulating the contraction of vertebrate striated muscle fibers. Mutations affecting phosphorylation of the RLC have been shown to correlate with certain familial hypertrophic cardiomyopathies (FHCs), most notably the E22K mutation known to prevent serine-15 RLC phosphorylation. We hypothesise that altered RLC phosphorylation affects both the Ca2+ -sensitivity and power output of permeabilized cardiac trabeculae, myofilaments and single myosin molecules.