Phosphorylation of the light-chain components of myosin from cardiac and red skeletal muscles.
1. The light-chain components of myosin from cardiac muscle (19000 and 27000 daltons) and of rabbit soleus and crureus muscles (19000, 27000 and 29000 daltons) were characterized. 2. The 19000-dalton components in carciac- and red-skeletal-muscle myosins were spontaneously modified to a component of slightly higher net negative charge. 3. The 19000-dalton component in cardiac and red skeletal muscles and their modified forms were phosphorylated by myosin light-chain kinase. 4. Evidence was obtained for the presence of myosin light-chain kinase in cardiac and red skeletal muscles. 5. Myosin light-chain kinase catalysed the phosphorylation of the whole light-chain fraction from white and red skeletal muscle at similar rates. The light-chain fraction of cardiac-muscle myosin was phosphorylated at a significantly lower rate. 6. The light-chain components of cardiac-muscle myosin and their phosphorylated froms were separated by ion-exchange chromatography and their amino acid compositions determined.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D008970:Molecular Weight; D009132:Muscles / Q000032:analysis; D009206:Myocardium / Q000032:analysis; D009218:Myosins / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism*; D011817:Rabbits
D000596:Amino Acids; D011494:Protein Kinases; D009218:Myosins