Comparative Studies on the Myelin Proteins of Bovine Peripheral Nerve and Spinal Cord

Abstract— (1) Two myelin fractions of bovine peripheral nerve and spinal cord have been studied comparatively. Cholesterol as well as cerebroside content per mg of protein in the peripheral nerve myelin was less than that in the spinal cord myelin, while no significant difference in the total phospholipid content was noted. (2) The basic proteins in myelin fractions were quantitatively estimated by disc gel electrophoresis. Around one‐fourth of the total myelin protein in the bovine peripheral nerve was a basic protein with a mobility of 1.07 relative to lysozyme by Reisfeld's disc gel electrophoresis. (3) The myelin proteins in the peripheral nerve were less completely solubilized than those of the spinal cord by treatment with deoxycholate as well as by Triton‐salt solution. The protein fractions obtained from the peripheral nerve myelin by techniques similar to that for obtaining the proteolipids from the spinal cord myelin, contained different types of protein. (4) 2′,3′‐Cyclic nucleotide 3′‐phosphohydrolase activity in the peripheral nerve myelin was only one tenth of that in the spinal cord myelin. The Triton‐salt insoluble fraction showed remarkable high activity among subfractions of the spinal cord myelin. (5) By immunological studies, it may be concluded that an antigenic substance for experimental allergic neuritis was localized in the peripheral nerve myelin, but not in its basic protein.