Conformation of myosin in dilute solution as estimated from hydrodynamic properties

On the basis of the current knowledge of the structure and dimensions of myosin and its parts, we analyze available data on hydrodynamic properties (translational diffusion, rotational diffusion, and intrinsic viscosity) for comparison with values calculated for models with varying geometry. Special attention is paid to detecting flexibility effects in those properties. After obtaining a plausible model for subfragment S-1, we concentrate on the conformation of the rodlike parts of myosin. Although uncertainties in the experimental values do not allow a rigorous, quantitative analysis, we show how hydrodynamic data provide evidence for the flexibility of the rod at the joint of subfragment S-2 and light meromyosin.