Peptide competition of actin activation of myosin-subfragment 1 ATPase by an amino terminal actin fragment

• Published in: FEBS letters Vol. 294; no. 1; pp. 31 - 34
• Main Authors: Kögler, Harald, Moir, Arthur J.G., Trayer, Ian P., Rüegg, J.Caspar
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 02-12-1991; Elsevier
• Subjects: Actin; Actin peptide; Actins - metabolism; Acto-S1-ATPase; Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Ca(2+) Mg(2+)-ATPase - metabolism; Cyanogen Bromide; Enzyme Activation; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Hydrolases; Kinetics; Muscles - enzymology; Myosin Subfragments - metabolism; Myosins - metabolism; Peptide Fragments - isolation & purification; Peptide Fragments - metabolism; Rabbits; S1-ATPase; Spectrometry, Fluorescence; Actin peptide; Acto-S1-ATPase; Actin; S1-ATPase; Competitive fixation; Regulation(control); Enzyme; ATPase; Myosin; N terminal-Sequence; Actins; Binding site
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(91)81336-7

The amino-terminal region of actin participates in the binding of myosin subfragment 1 (S1) during cross-bridge cycling, thereby assisting in the activation of the magnesium-dependent myosin ATPase. Effects of three actin fragments on the magnesium-dependent S1 and acto-S1 ATPase activities in solution were studied. One of the peptides, containing residues actin 1–44, mimicked the S1 ATPase-activating properties of actin and in turn inhibited acto-S1 ATPase both in a concentration-dependent manner. This suggests peptide competition for the actin binding site on myosin. The other fragments, residues actin 1–18 and 82–119, respectively, had no detectable effect on S1- and acto-S1 ATPase activity.