Cell surface myosin in cultured fibroblasts.
The surface components of L-929 mouse fibroblast cells in monolayer culture have been labeled with 125I by lactoperoxidase-catalyzed iodination procedure. One of the membrane proteins iodinated has been shown to be myosin as follows: it has the same electrophoretic mobility (molecular weight 200,000 daltons) as myosin heavy chain on sodium dodecylsulfate polyacrylamide gels and the labeled myosin is specifically precipitated by fibroblast myosin antiserum from a preparation of purified plasma membrane that have been solubilized by treatment with 1% Triton X-100. One other 125I-labeled membranes protein (molecular weight 210, 000 daltons) is precipitated along with myosin; the latter does not combine directly with antimyosin antibody. This was determined by reacting polyacrylamide gels containing the separated membrane proteins with fibroblast myosin antiserum; myosin was the only membrane protein reacting with the antibody as determined by two separate methods. Membrane myosin is not labeled when the cells are grown in 14C-D-glucosamine or treated with galactose oxidase and potassium borotritide. Thus membrane myosin is probably not a glycoprotein.
D002462:Cell Membrane / Q000032:analysis*; D011232:Chemical Precipitation; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins / Q000032:analysis; D007118:Immunoassay; D007457:Iodine Radioisotopes; D007739:L Cells; D008970:Molecular Weight; D009218:Myosins / Q000032:analysis*
D006023:Glycoproteins; D007457:Iodine Radioisotopes; D009218:Myosins