Morphological changes in myofibrils and glycerinated muscle fibers on treatment with cathepsins D and L

Morphological changes in myofibrils and glycerinated muscle fibers on treatment with cathepsins D and L obtained from rabbit skeletal muscle were studied by phase contrast and electron microscopy. Cathepsin D degraded the Z-line and filaments adjacent to the H-zone. Cathepsin L caused the fragmentation of myofibrils, and degraded the Z-line and M-line. Both cathepsins induced disturbance of the lateral arrangement of myofibrils.