title: Immunohistochemical localization of contractile proteins in limulus striated muscle.
abstract: Limulus paramyosin and myosin were localized in the A bands of glycerinated Limulus striated muscle by the indirect horseradish peroxidase-labeled antibody and direct and indirect fluorescent antibody techniques. Localization of each protein in the A band varied with sarcomere length. Antiparamyosin was bound at the lateral margins of the A bands in long ( approximately 10.0 micro) and intermediate ( approximately 7.0 micro) length sarcomeres, and also in a thin line in the central A bands of sarcomeres, 7.0- approximately 6.0 micro. Antiparamyosin stained the entire A bands of short sarcomeres (<6.0). Conversely, antimyosin stained the entire A bands of long sarcomeres, showed decreased intensity of central A band staining except for a thin medial line in intermediate length sarcomeres, and was bound only in the lateral A bands of short sarcomeres. These results are consistent with a model in which paramyosin comprises the core of the thick filament and myosin forms a cortex. Differential staining observed using antiparamyosin and antimyosin at various sarcomere lengths and changes in A band lengths reflect the extent of thick-thin filament interaction and conformational change in the thick filament during sarcomeric shortening.
mesh_terms: D000205:Actomyosin / Q000032:analysis; D000818:Animals; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D001666:Binding Sites, Antibody; D003386:Brachyura; D005455:Fluorescent Antibody Technique; D008858:Microscopy, Phase-Contrast; D008954:Models, Biological; D009124:Muscle Proteins / Q000032:analysis*; D009132:Muscles / Q000032:analysis*; D009149:Mustard Plant / Q000201:enzymology; D009218:Myosins / Q000032:analysis; D010544:Peroxidases / Q000494:pharmacology; D010946:Plants, Medicinal; D011233:Precipitin Tests; D011817:Rabbits / Q000276:immunology; D013194:Staining and Labeling
chemical_list: D009124:Muscle Proteins; D000205:Actomyosin; D010544:Peroxidases; D009218:Myosins