Calcium-dependent muscle contraction in obliquely striated Ascaris suum muscle

• Published in: Comparative biochemistry and physiology. B, Comparative biochemistry Vol. 82; no. 2; pp. 395 - 403
• Main Authors: Donahue, Manus J., Michnoff, Carolyn A., Masaracchia, Ruthann A.
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 1985
• Subjects: Animals; Ascaris - physiology; Ascaris suum; calcium; Calcium - pharmacology; Electrophoresis, Polyacrylamide Gel; Muscle Contraction - drug effects; Muscle Proteins - isolation & purification; muscles; Muscles - drug effects; Muscles - physiology; Myofibrils - ultrastructure; myosin; Myosin-Light-Chain Kinase; Myosins - metabolism; Phosphorylation; Protein Kinases - metabolism; Space life sciences; Tropomyosin - metabolism; Troponin - metabolism; TPCK; MLCK; SDS; DTT; BAME; PAGE; Tris; EGTA; PMSF; ME; MES; N, N, N′, N′-tetraacetic acid; M r
• ISSN: 0305-0491
• DOI: 10.1016/0305-0491(85)90259-7

1. 1. The regulatory proteins of Ascaris suum striated skeletal muscle were partially purified and characterized. 2. 2. A tropomyosin isoform ( M r 41K) and three troponin subunits identified as troponin T ( M r 37.5K), troponin I ( M r 25.5K) and troponin C ( M r 18.5K) were purified. 3. 3. Three myosin light chains ( M r 25K, 19K, and 17K) were isolated from washed ascaris actomyosin; the 19K subunit was phosphorylated in vitro. 4. 4. A calcium/calmodulin-dependent myosin light chain kinase activity was identified in the muscle. 5. 5. In contrast to previously reported data suggesting that Ascaris obliquely striated muscle contraction is regulated by a myosin-mediated mechanism, these data indicate that all of the proteins required for actin-mediated, calcium-dependent muscle contraction are present in this tissue.