Purification, phosphate content and phosphorylation of myosin from human vascular smooth muscle.
Myosin was prepared from human umbilical artery and some of its properties were studied. The yield of myosin after ultracentrifugation was 4.3-13.6 mg/gr wet weight of tissue (mean: 8.6 mg/gr). A considerable amount of phosphate bound to the myosin was found in all preparations. Phosphate content of umbilical arterial myosin was higher than what had been found in our earlier works in skeletal muscle myosin. Phosphate content of umbilical arterial myosin also could be further increased by incubation in ATP containing media. While the rate of phosphorylation of human umbilical arterial myosin was slower than that of skeletal muscle myosin, the saturated phosphate levels reached with 0.5 mM ATP concentration were higher for vascular myosin. The slower phosphate uptake rate of vascular myosin may be related to the slower contraction rate of this muscle type. After alkaline hydrolysis of lipid free myosin, 7 or 8 peaks of N-phosphoryl amino acids and phosphorylated amino acid derivates could be separated by ion exchange chromatography.
Fazekas
S
S
2nd Institute of Biochemistry, Semmelweis University Medical School, Budapest, Hungary.
Nádasy
G L
GL
Monos
E
E
Kovách
A G
AG
Székessy-Hermann
V
V
D000255:Adenosine Triphosphate / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009218:Myosins / Q000302:isolation & purification* / Q000378:metabolism; D010766:Phosphorylation; D014469:Umbilical Arteries / Q000378:metabolism
D000255:Adenosine Triphosphate; D009218:Myosins