1. Cardiac V1 And V3 Myosins Differ in Their Hydrolytic and Mechanical Activities In Vitro
by Peter VanBuren, David E. Harris, Norman R. Alpert, and David M. Warshaw
Circulation Research
Volume 77(2):
August 1, 1995
Copyright © American Heart Association, Inc. All rights reserved.

2. Time course of force generation by V1 cardiac myosin.
Time course of force generation by V1 cardiac myosin. The myosin population produced a maximum steady state isometric force for at least 0.6 seconds. The maximum isometric force value was determined by averaging force over this steady state period, and this value was used to construct the maximum force vs actin filament length plot in Fig 3. Note that at peak force for this experiment, the actin filament breaks, and the microneedle returns to its previous zero-force baseline, which serves as a control against baseline drift. The microneedle deflection (ie, force) was determined at a 0.2-second interval from digitized video images.
Peter VanBuren et al. Circ Res. 1995;77:
Copyright © American Heart Association, Inc. All rights reserved.

3. Illustration of two-state cross-bridge cycle.
Illustration of two-state cross-bridge cycle. During the hydrolysis of a single ATP molecule (cross-bridge cycle), the myosin motor is either attached and strongly bound to actin, generating its unitary force (Funi), or detached (ie, weakly bound) and not generating any force (top). The duty cycle (f) is indicated as a fraction of the cross-bridge cycle. The average cross-bridge force (Favg) per cycle is calculated as the product of Funi and f. Two examples are presented to illustrate how a twofold increase in either Funi (middle) or f (bottom) can result in a twofold increase in Favg.
Peter VanBuren et al. Circ Res. 1995;77:
Copyright © American Heart Association, Inc. All rights reserved.

4. Maximal isometric steady state force vs actin filament length in contact with myosin-coated surface for V1 myosin (•) and V3 myosin (○).
Maximal isometric steady state force vs actin filament length in contact with myosin-coated surface for V1 myosin (•) and V3 myosin (○). The data were fitted by linear regression (solid lines), with the 95% confidence limits for the regression indicated by the dashed lines. The slopes of the regressions are reported in the Table.
Peter VanBuren et al. Circ Res. 1995;77:
Copyright © American Heart Association, Inc. All rights reserved.