The intermediate filament protein desmin in cardiac and skeletal muscle from normal and dystrophic (BIO 14.6) hamsters.

Electrophoretic separation on polyacrylamide gels of polypeptides extracted from skeletal and cardiac muscle of BIO 14.6 dystrophic, carrier, and random-bred normal hamsters demonstrates similar quantities and electrophoretic mobility of a protein having a relative mass of 52 000 daltons (apparent isoelectric point 6.2) from all sources examined; we have tentatively identified this protein as the intermediate filament protein desmin. Reaction of such separated polypeptides transferred to nitrocellulose blots with antibodies raised against this protein fails to show immunological differences in this 52 000 dalton protein in cardiac and skeletal muscle from normal and dystrophic animals. Indirect immunofluorescence analysis of skeletal myofibrils from 30-to 60-day normal and dystrophic animals shows no differences in Z-line staining when immunoglobulins from anti-alpha-actinin serum are used as primary antibodies. Immunoglobulins from the putative anti-desmin serum also produce Z-line staining of skeletal myofibrils from normal animals, but fail to bind to the Z-lines of some skeletal myofibrils from dystrophic hamsters.