An endogenous lectin "CSL" interacts with glycoprotein components in peripheral nervous system myelin

An endogenous mannose binding lectin isolated from the rat cerebellum, CSL, was localized using immunocytochemical techniques in adult and in developing rat sciatic nerve. The lectin is present in Schwann cell cytoplasm and in compact myelin. It is present very early in Schwann cells and persists throughout postnatal sciatic nerve development. Endogenous ligands for the lectin were detected using iodinated-CSL binding to proteins blotted after polyacrylamide gel electrophoresis. Probably PO and MAG glycoproteins are specifically bound by CSL in contrast with numerous other Concanavalin A binding glycoproteins. A 31 kDa glycoprotein identified in purified preparations of axons of young rats also reacts with CSL. Based on the present developmental biochemical and immunochemical studies, an hypothetical scheme is proposed for the molecular basis of axon-Schwann cell interactions and of stabilization of compact myelin.