Monoclonal antibody 1C8 raised against postnatal nerve growth cone-enriched fraction recognizes sialylated carbohydrate epitope in both neurons and exocrine goblet cells

Abstract

Monoclonal antibody (mAb) 1C8 was raised against growth cone-enriched fractions (GCF) of postnatal day 0, 7, and 14 rat brains, and its immunoreactivity was characterized. A Western blot analysis of the rat brain membrane fraction showed that mAb 1C8 recognized 23 and 50 kDa proteins (designated GP23 and GP50). After various glycosidase treatments, immunoreactivity to both GP23 and GP50 disappeared with the use of sialidase from Arthrobacter ureafaciens alone. Reactivity with mAb 1C8 was found, not only on neurons in the central nervous system, but also on exocrine goblet cells in rat colon. Immunoelectron microscopic analyses of colon goblet cells demonstrated that this immunoreactivity was restricted to the limiting membranes of secretory granules. These findings indicate that mAb 1C8 recognizes an epitope common to neural and exocrine cells, including sialic acid residue(s). MAb 1C8 may thus be useful for examining the changes in glycosylation during neural development as well as the relationships between neurons and goblet cells.