Isolation and immunohistochemical localization of a "Purkinje cell specific glycoprotein subunit from rat cerebellum

The indirect immunohistochemical method has been used to determine the cellular localization of a Con A-binding glycoprotein subunit insoluble in Triton X-100, isolated from a rat cerebellar membrane pellet by Con A-Sepharose affinity chromatography and preparative PAGE electrophoresis in the presence of sodium dodecyl sulfate. This glycoprotein subunit (N-terminal amino acid Ala; MW 24,000 daltons) contains 24% carbohydrate (w/w) mainly mannose but also N-acetylglucosamine, galactose and sialic acid. At the optical level, the antiserum raised against this glycoprotein stains the whole Purkinje cell (dendrite, cell body and even the axon) but not the other cerebellar neurons. This staining is not eliminated when the antiserum is absorbed by rat forebrain or brain stem homogenates but is, in contrast, completely abolished by absorption with rat cerebellum homogenates. Thus, this antigen appears to be in the central nervous system exclusive to the cerebellum, and in the cerebellum specific for Purkinje cells. This antigen is present throughout the postnatal development of the rat cerebellum and the staining is already very strong at the fifth postnatal day.