Myosin in cultured human endothelial cells.
Myosin was isolated from cultured human endothelial cells by extraction with 0.6 M KCl and chromatography on Sepharose 4B. The extracted endothelial cell protein was identified as myosin by the characteristic ATPase profile, that is, the ATPase was activated by Ca2 + and EDTA and inhibited by Mg2 +. On sodium dodecyl sulphate polyacrylamide gel electrophoresis, the endothelial cell myosin heavy chain migrated with a molecular weight of 200 000 as did rabbit uterine and human platelet myosin heavy chains. A crude preparation of the endothelial cell myosin reacted immunologically with an antiserum to platelet myosin, a smooth muscle type of myosin. In indirect immunofluorescence studies, antiserum to the purified endothelial cell myosin stained cultured endothelial cells in a fibrillar pattern. The fibrillar pattern was more intense when the endothelial cells were stained with antiserum to platelet myosin. The presence of myosin in the endothelial cell provides a basis for the contractility of these cells. This contractile property may plan an important role in the physiologic function of these cells.
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000918:Antibody Specificity; D000941:Antigens / Q000032:analysis; D001792:Blood Platelets / Q000032:analysis; D002478:Cells, Cultured; D004727:Endothelium / Q000032:analysis* / Q000166:cytology / Q000201:enzymology; D006801:Humans; D008970:Molecular Weight; D009218:Myosins / Q000276:immunology / Q000302:isolation & purification*; D014471:Umbilical Veins / Q000166:cytology
D000941:Antigens; D000251:Adenosine Triphosphatases; D009218:Myosins