Evidence for the presence of major peripheral myelin glycoprotein P-0 in mammalian spinal cord and a change of its glycosylation state during aging

Glycoproteins, which react with Lens culinaris agglutinin, in the membrane preparation of various portions of brains and spinal cords, obtained from 9 -week-old rats and 29-month-old rats, were comparatively analyzed by SDS-po lyacrylamide gel electrophoresis, Ln contrast to the samples from brain, wh ich showed similar staining patterns in the two different age groups, the g lycoprotein patterns of spinal cords showed marked differences by the age o f donors. The most prominent evidence is that a glycoprotein with an appare nt molecular weight of 30 kDa (gp30) was detected in the aged rats, but not in the young adult rats. Based on the amino acid sequence data around the glycosylation site, the gp30 was identified as P-0, which is a member of im munoglobulin superfamily and a major structural component of mammalian peri pheral nerve myelin, This is the first report indicating that P-0, which ha s been considered as a peripheral nerve-specific glycoprotein, occurs also in the spinal cord of mammals. Zn addition, nonglycosylated P-0 molecule co uld be detected in the spinal cord of young adult rats by anti-P-0 polyclon al antibody These results indicate that the glycosylation state of the Po m olecule in the spinal cord changes during aging.