title: Trinitrophenylation of smooth muscle myosin.
abstract: The reaction of trinitrobenzenesulfonate with gizzard myosin was studied. The initial phase of the reaction involved two residues and at this level of modification the following was observed: the Mg2+-ATPase of myosin, the actin-activated ATPase of phosphorylated myosin and the phosphorylation kinetics of myosin were not affected. However, trinitrophenylation did induce an activation of the actin-activated ATPase of dephosphorylated myosin and in this respect mimicked the effect of light chain phosphorylation. The Mg2+-dependence of actin-activated ATPase also is altered on trinitrophenylation. These alterations of enzymatic properties could be at least partly explained by the finding that trinitrophenylation favored the 6S conformation of myosin.
authors.forename: S
authors.initials: S
authors.lastname: Srivastava
authors.forename: M
authors.initials: M
authors.lastname: Ikebe
authors.forename: D J
authors.initials: DJ
authors.lastname: Hartshorne
mesh_terms: D000199:Actins / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D005895:Gizzard, Avian; D009130:Muscle, Smooth / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism*; D009578:Nitrobenzenes / Q000494:pharmacology*; D010766:Phosphorylation; D011487:Protein Conformation; D014302:Trinitrobenzenesulfonic Acid / Q000494:pharmacology*; D014422:Turkeys
chemical_list: D000199:Actins; D009578:Nitrobenzenes; D014302:Trinitrobenzenesulfonic Acid; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D009218:Myosins; D000252:Calcium-Transporting ATPases