Regulation of the actin-activated ATPase activity of Acanthamoeba myosin I by cross-linking actin filaments.

摘要: Abstract The actin-activated Mg2+-ATPase activity of phosphorylated Acanthamoeba myosin I was previously shown to be cooperatively dependent on the concentration (Albanesi, J. P., Fujisaki, H., and Korn, E. D. (1985) Biol. Chem. 260, 11174-11179). This observation rationalized by assuming that contains a high-affinity low-affinity F-actin-binding site binding at is responsible for ATPase activity. Therefore, enzymatic would correlate with cross-linking actin filaments I, cooperative increase in specific high myosin:actin ratios result from fact one molecule effective F-actin neighboring molecules. model predicts should occur below required interactions if are cross-linked catalytically inert proteins. prediction has been confirmed either three gelation factors isolated Acanthamoeba, which not described, or enzymatically inactive unphosphorylated I.