Enzymes that synthesize the IB4 epitope are not sufficient to impart IB4 binding in dorsal root ganglia of rat

Abstract

The isolectin B4 (IB4) stains a subset of small and medium-sized dorsal root ganglion (DRG) neurons by binding to terminal α-galactose on glycoproteins and glycolipids. The enzymes α(1,3)galactosyltransferase (1,3GT) and isoglobotriaosylceramide synthase (iGb3S) synthesize the galactose-α(1,3)-galactose group, which is the most common carbohydrate containing terminal α-galactose. 1,3GT preferentially glycosylates proteins whereas iGb3S glycosylates lipids. We generated antibodies against rat 1,3GT and iGb3S that were used for immunohistochemical staining of DRG cells. Virtually all neurons that bound IB4 expressed both enzymes, suggesting that IB4 binds to both glycoproteins and glycolipids ..