Distribution of calcium activated neutral proteinase (mM CANP) in myelin and cytosolic fractions in bovine brain white matter.

The activity of calcium-activated neutral proteinase (mM CANP) was determined in homogenate, myelin and supernatant of bovine brain corpus callosum. The enzyme activity in homogenate and myelin was increased eleven and thirteen-fold respectively by Triton X-100. Myelin prepared by the method of Norton and Poduslo as well as by a modified method, was shown to contain most (more than 50%) of homogenate mM CANP activity. The specific activity was highest in myelin, and increased almost three times more than the homogenate. Supernatant only contained 17% of enzyme activity. It is concluded from these studies that mM CANP is tightly bound to the membrane and predominantly associated with the myelin sheath.