Enzymatic mechanochemistry. I. The interaction of heavy meromyosin with “immobilized adenosine triphosphate”

Abstract

ATP was covalently bound to an agarose gel. The insolubilized ATP was found to be capable of specifically binding heavy meromyosin. The adsorbed heavy meromyosin could be eluted by ATP in solution. Both binding and elution by ATP of heavy meromyosin were not much effected by Ca 2+, Mg 2+ or EDTA. While the water-soluble polyalanine-myosin was also found to be adsorbed, myosin in 0.5 M KCl did not seem to be adsorbed by agarose-ATP. Both Mg 2+ and Ca 2+ appear to activate the splitting of bound ATP by heavy meromyosin to practically the same extent. We prepared water-soluble derivatives of ATP in which ATP underwent the same chemical modification required for its coupling to agarose but in which the agarose component was absent. Their splitting by heavy meromyosin was also activated by Mg 2+ though to a lesser extent but actin did not influence this reaction. Possible relations between our findings and the various stages of the reaction between myosin and ATP, as well as the potential use of columns filled with insolubilized NTPs for the separation and purification of myosin and of its subfragments, are discussed.