THE STEP-SIZE DISTANCE IN MUSCLE-CONTRACTION - PROPERTIES AND ESTIMATES

The step-size distance in muscle contraction is obtained using the ste p-size distance equation z = u/n, where z is the step-size distance, u is the actin filament velocity and n is the ATPase rate of splitting. In a previous study a step-size distance of about 17 Angstrom at no l oad was determined for intact frog muscle. Some properties of the step -size distance equation are described. We have now made estimates of t he step-size distance z for a variety of muscles using existing physio logical and biochemical data in the literature. The estimates are list ed in Tables 1 and 2. We find that the step-size distances are cluster ed in the range 13-17 Angstrom for nearly all muscles. Copyright (C) 1 996 Elsevier Science B.V.