Structural changes in muscle fiber contractile proteins studied by polarization ultraviolet fluorescence microscopy. VIII. The effect of glutaraldehyde and phalloidine on F-actin conformation

Conformational changes in F-actin, induced by glutaraldehyde or phalloidin, were found in glycerinated m. psoas rabbit fibres (ghost and reconstructed fibres). It is shown that the conformational changes of F-actin decreased the thin filament flexibility as well as weakened fibre's contractility. It is assumed that the stabilization in F-actin structure may be an important factor involved in the mechanism of muscle contraction regulation.