Myosin Crossbridge Kinetics: Figure 4 illustrates example results from length perturbation assays. Length perturbations are useful, because they induce a muscle force response indicative of myosin function. Myosin is the molecule responsible for force production. Myosin is specifically an enzyme that converts the chemical energy of MgATP into mechanical energy like muscle force. The time scale of the enzyme activity is milliseconds and can be lengthened or shortened by length perturbation. There are two kinds of length perturbation useful for detecting myosin enzyme kinetics and its sensitivity to length change: sinusoidal analysis and quick stretch – both illustrated in Figure 4.
