Analysis of equatorial x-ray diffraction patterns from skeletal muscle.

Some of the factors that affect the intensities and the phases of the first five equatorial x-ray reflections from skeletal muscle are studied by simplified models describing axially projected mass distributions in unit cells. Examples of mass distributions that produce various phase combinations and intensities are presented. Effects due to radial movement of crossbridges and those due to mass transfer between the thick filament and the thin filament regions are compared. In addition, the study suggests that some features in the reconstructed filament structures could be due to the consequences of limited resolution.