Immunoelectron microscopic localization of C-terminus of 43-kDa dystrophin-associated glycoprotein in normal human skeletal myofibers.

Ultrastructural localization of the C-terminus of a 43-kDa dystrophin-associated glycoprotein (43-DAG) and its relation to dystrophin were investigated in normal human skeletal myofibers by using single and double immunogold labelling methods. The C-terminal end of 43-DAG antibody was localized ultrastructurally at the inside surface of muscle plasma membrane and the sarcoplasmic side of the plasma membrane invaginations. Double immunolabelling electron microscopy disclosed that signals of the C-terminal end of 43-DAG and dystrophin were often associated with each other and formed a doublet at the inside surface of plasma membranes in normal human skeletal myofibers.