Chicken leg muscle α-connectin as studied by a monoclonal antibody to the1200 kDa fragment

Abstract Chicken leg gracills muscle contained only α-connectin ( ca 3000 kDa) without β-connectin. When myofibrils were kept standing for 20 hr at 4°C, α-connectin was degraded to β-connectin ( ca 2000 kDa) and 1200 kDa peptide. The latter was prepared from myofibrils and purified by gel filtration in the presence of SDS. A monoclonal antibody, α7, to this 1200 kDa fragment was prepared. The antibody reacted with the 1200 kDa fragment and its mother molecule α-connectin, but not with β-connectin. Immunoelectron microscopy using α7, as well as other antibodies to chicken breast muscle β-connectin, revealed that the 1200 kDa peptide covered the portion of α-connectin from the Z line to the N 2 line region in the I band of chicken leg gracilis muscle sarcomeres. The results were in good agreement with those observed in rabbit skeletal muscle.