Cross-bridge properties in the rigor state.

The inability of applied strain to affect the equatorial diffraction pattern of the rigor fiber indicates that the attachment angle of S1 to the actin filament is extremely stable. The effects of lattice spacing on fiber length (at constant force) and force (at constant length) indicate that the S1 moiety is connected to the surface of the myosin filament by a link that is between 3 and 12 nm in length, which is considerably less than 60 nm length that has been assumed previously.