title: The enzymic properties of a modified ox heart myosin adenosine triphosphatase on covalent binding to an insoluble cellulose matrix.
abstract: The preparation of ox heart myosin and its partial digestion with cellulose-bound papain is described. A procedure is outlined by which heavy meromyosin subfragment 1 can be covalently bound to a cellulose ion-exchange matrix. Attachment of heavy meromyosin subfragment 1 to the insoluble matrix results in a change in the ion specificity towards ATP hydrolysis. Unlike the soluble enzyme the bound form is activated by both Ca(2+) and Mg(2+). Maximal activation by Ca(2+) occurred at a lower concentration for the bound enzyme. Mg(2+) activates at a concentration which causes near-maximal inhibition of the Ca(2+)-activated adenosine triphosphatase (ATPase) of the non-bound enzyme. The Mg(2+)-activated ATPase of the bound enzyme was in turn inhibited by the presence of Ca(2+). The activation by Mg(2+) resembles the characteristic enzymic action of the actin-subfragment 1 complex.
mesh_terms: D000251:Adenosine Triphosphatases; D000818:Animals; D002118:Calcium; D002417:Cattle; D002482:Cellulose; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008274:Magnesium; D009124:Muscle Proteins; D009206:Myocardium / Q000201:enzymology; D009218:Myosins; D010206:Papain; D011485:Protein Binding
chemical_list: D009124:Muscle Proteins; D002482:Cellulose; D010206:Papain; D000251:Adenosine Triphosphatases; D009218:Myosins; D008274:Magnesium; D002118:Calcium