Endogenous
sugar-
binding proteins were localized in sections of human and pig peripheral nerves by the application of two types of labelled
ligands:
neoglycoproteins (chemically glycosylated
carrier proteins that had proven to be histochemically inert) and desialylated, naturally occurring
glycoproteins. These
proteins allowed evaluation of the presence and distribution of endogenous receptors for
carbohydrates, commonly present in cellular
glycoconjugates. (Neo)
glycoprotein binding was similar, but not identical, for the two types of mammalian peripheral nerves. The pig nerve differed from the human nerve in more pronounced staining when using different types of
beta-galactoside-terminated (neo)
glycoproteins and charge-carrying
neoglycoproteins, such as
bovine serum albumin, bearing
galactose-6-phosphate residues,
glucuronic acid residues, and
sialic acid residues. Comparative biochemical analysis of certain classes of
sugar receptors by affinity chromatography and gel electrophoresis revealed the presence of
sugar receptors that can contribute to the histochemical staining in a pattern with certain significant differences among rather similar expression for the two species. The assessment of
sugar receptor distribution by application of (neo)
glycoprotein binding among morphologically defined regions in nerves may hold promise in detecting developmental regulation and changes during
nerve degeneration and subsequent regeneration after
trauma or pathological states. Correlation of these results to changes in the structure and abundance of
glycoconjugates, which are the potential physiological
ligands of endogenous
sugar receptors commonly detected by
plant lectins, may help to infer functional relationships.