Subunit Structure of Myosin

Myosin Subunit Interactions

The 19,000-dalton light chain (LC2) can be completely and reversibly removed from chicken pectoralis myosin in 1 mM EDTA and 5 mM ATP using immunoaffinity chromatography at 37 “C. Earlier methods have led to only partial removal of LC2 or have caused limited degradation of the heavy chain. Electron microscopy of LC2-deficient myosin showed it to have a marked tendency to aggregate into oligom...

Solution structure of the inhibitory phosphorylation domain of myosin phosphatase targeting subunit 1.

Subunit exchange between smooth muscle myosin filaments

Myosin filaments are in equilibrium with a "critical concentration" of monomer (Josephs & Harrington, 1966). Our recent studies with smooth muscle myosin minifilaments and larger synthetic filaments suggest that this monomer pool undergoes more extensive exchange with the polymer than would occur if only polymer ends were involved. This observation provides a possible explanation for the behavi...

Myosin subunit composition in human developing muscle.

Previous pyrophosphate-gel studies have reported the existence of embryonic neonatal myosin isoenzymes in human developing muscle. The present investigation was undertaken to characterize their subunit composition more precisely. Two immature muscle myosins are contrasted with adult myosin: neonatal myosin and foetal myosin. The neonatal form of myosin is weakly cross-reactive with rabbit slow ...

Regulation of myosin phosphatase through phosphorylation of the myosin-binding subunit in platelet activation.

Human platelets were found to contain myosin phosphatase consisting of a 38-kD catalytic subunit of protein phosphatase type 1delta, a 130-kD myosin-binding subunit (MBS) and a 20-kD subunit, all of which cross-reacted with antibodies against these subunits of smooth muscle myosin phosphatase. Anti-MBS antibody coimmunoprecipitated RhoA and Rho-kinase of human platelets. Platelets MBS is a subs...