Tissue-specific and non-tissue-specific heavy-chain isoforms of myosin in the brain as revealed by monoclonal antibodies.
Four types of monoclonal antibody (BM-1, BM-2, BM-3 and BM-4) each having distinctive tissue specificity were obtained by immunizing mice with purified bovine cerebrum myosin. Both BM-1 and BM-2 reacted most efficiently with cerebrum myosin and less efficiently with myosins from other limited nonmuscle tissues, the tissue specificity of BM-1 being much narrower than that of BM-2. BM-3 reacted more efficiently with several other nonmuscle myosins than with cerebellar or cerebral myosin. BM-4 recognized various nonmuscle and smooth muscle myosins with a nearly equal efficiency. Cerebral myosin as well a cerebellar myosin contained two or more electrophoretic variants of the heavy chains. BM-1 and BM-3 as well as BM-2 and BM-3 were found to recognize selectively these distinct heavy-chain isoforms. The antigenic sites of the three tissue-specific antibodies (BM-1, BM-2 and BM-3) were all localized near the head/tail junction of the myosin molecules, while that of non-tissue-specific antibody BM-4 was near the center of the tail. These and additional results indicate that mammalian brain tissues as well as several other nonmuscle tissues contain multiple heavy-chain isoforms of myosin, the levels of which differed considerably from one tissue to another.
Kimura
A
A
Department of Legal Medicine, Wakayama Medical College, Japan.
Tsuji
T
T
Matoba
R
R
Fujitani
N
N
Ohmori
K
K
Matsumura
S
S
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism*; D002417:Cattle; D003429:Cross Reactions; D000939:Epitopes; D008854:Microscopy, Electron; D009218:Myosins / Q000276:immunology / Q000378:metabolism* / Q000648:ultrastructure; D009419:Nerve Tissue Proteins / Q000276:immunology / Q000378:metabolism / Q000648:ultrastructure; D014018:Tissue Distribution
D000911:Antibodies, Monoclonal; D000939:Epitopes; D009419:Nerve Tissue Proteins; D009218:Myosins