Acetylcholinesterase solubilized from normal and dystrophic muscle by collagenase treatment.

The activity of specific acetylcholinesterase, assayed in the presence of an inhibitor of nonspecific cholinesterase, was significantly lower in the leg muscle of dystrophic mice of Bar Habor strain 129 than in that of normal mice. However, the nonspecific butyrylcholinesterase activity was much higher in dystrophic muscle than in normal muscle. Collegenase released more acetylcholinesterase activity into the soluble fraction derived from homogenized normal muscle than into that derived from dystrophic muscle. The collagenase-released activity in the normal muscle contained about 95% specific acetylcholinesterase while that from dystrophic muscle contained only 74% specific acetylcholinesterase activity. The acetylcholinesterase activity solubilized by collagenase from control muscle contained the highest activity in 10 S form with decreasing activity of 16 S and 4 S forms, but that from dystrophic muscle contained much less of the 16 S and 10 S forms with more 4 S form, compared to the controls.