A Biochemical Analysis of the Factors Influencing P0 Oligomerization in Xenopus laevis Peripheral Nerve Myelin

Abstract

Protein zero (P0), the major structural protein of peripheral nerve myelin, is a ~30 kDa integral membrane glycoprotein consisting of an extracellular domain, a transmembrane domain, and a palmitoylated cytoplasmic domain. In native membranes of Xenopus laevis it exists primarily as a dimer. To determine the effects of glycosylation, acylation, and hydrophobic interactions on protein dimerization, I used SDS polyacrylamide gel electrophoresis (SDS-PAGE), Western blotting, and high-performance thin layer chromatography (HPTLC) to analyze the effects of deglycosylation, deacylation, and various detergent treatments on myelin isolated from Xenopus laevis sciatic nerve. These treatments showed no effect on P0 oligomerization, suggesting that glycosylation, acylation, and hydrophobic interactions disrupted by these detergents do not underlie P0 dimerization. The data points to the likelihood that covalent linkages contribute to P0 oligomerizaztion in Xenopus.