title: An x-ray diffraction study of contracting molluscan smooth muscle.
abstract: The living anterior byssus retractor muscle of Mytilus (ABRM), a smooth, "catch" muscle, has been studied by X-ray diffraction while relaxed and while tonically contracted. X-ray reflections were observed from the actin and paramyosin filaments and from the alpha-helical substructure of the paramyosin filaments. No differences in spacings or relative intensities were observed when the relaxed and contracting muscle patterns were compared. This result is consistent with a sliding filament mechanism involving an interaction between actin and paramyosin filaments.
mesh_terms: D000199:Actins; D000818:Animals; D049872:Bivalvia; D009119:Muscle Contraction; D009218:Myosins; D011487:Protein Conformation; D014961:X-Ray Diffraction
chemical_list: D000199:Actins; D009218:Myosins