Figure 2.

Kinetics of the post-recovery stroke M** structural state formation upon rapid mixing of myosin and metal.ATP. Magnesium, upturned triangles, manganese, triangles, calcium, circles, lines, fit. Mg.ATP shifts equilibrium towards M** state, Mn.ATP – towards M* state, indicating that Mn.ADP release is the rate limiting step. Myosin – Ca.ATP interaction produces fast equilibrium of M* and M**, depending on the forward and reverse rate constants. Concentrations after mixing, [ATP]=300 µM, [metal cation] = 3 mM, [myosin] = 0.4 µM. [Color figure can be viewed in the online issue, which is available at http://wileyonlinelibrary.com.]