Specific binding of anti-myosin and -actin gamma-globulins to the surface of trypsin-dissociated embryonic chick cells.
125I-labelled sheep anti-rabbit gamma-globulin antibodies were used to locate rabbit antibodies to smooth- and striated-muscle actomyosins at the surface of trypsin-dissociated embryonic chick cells. Statistical analysis of electron microscope autoradiographs revealed that the plasma membrane of these cells was significantly labelled with both antibodies. Further tests revealed that there were a significantly greater number of antigenic sites present on the cell surface for the gizzard smooth-muscle antibodies than for those against pectoralis straited-muscle actomyosin. It was further shown that both the rate and extent of binding of the 125I-labelled smooth-muscle actomyosin antibodies to the cells were greater than for anti-straited-muscle gamma-globulins. Binding of the former was reduced to a level similar to that of 125I-NIS conjugate by preincubation of the gamma-globulins with smooth-muscle heavy meromyosin, while a simiar reduction was observed when anti-pectoralis actomyosin was treated with actin. It was concluded that actin- and myosin-like proteins must now be considered as integral components of the plasma membrane.
D000199:Actins / Q000032:analysis* / Q000276:immunology; D000818:Animals; D001666:Binding Sites, Antibody; D002462:Cell Membrane / Q000032:analysis / Q000648:ultrastructure; D002642:Chick Embryo; D000939:Epitopes; D009130:Muscle, Smooth / Q000276:immunology; D009132:Muscles / Q000032:analysis* / Q000276:immunology / Q000648:ultrastructure; D009218:Myosins / Q000032:analysis* / Q000276:immunology
D000199:Actins; D000939:Epitopes; D009218:Myosins