DISTRIBUTION OF GLYCOPROTEINS WITH BETA-N-ACETYLGALACTOSAMINYLATED N-LINKED SUGAR CHAINS AMONG BOVINE-TISSUES

Only a small number of glycoproteins has been reported to contain N-li nked sugar chains with GalNAc beta 1 --> 4GlcNAc structure. Our previo us studies showed that most glycoproteins from bovine milk fat globule membranes contain beta-N-acetylgalactosaminylated N-linked sugar chai ns [Sato et al., J. Biochem. 114 (1993) 890-900], In order to study ho w widely this glycosylation occurs, lectin blot analysis of membrane g lycoproteins from 12 bovine tissues was performed using Wistaria flori bunda agglutinin (WFA), which interacts with oligosaccharides terminat ing with N-acetylgalactosamine. The WFA-positive bands were detected i n samples from most tissues except for intestine although the number a nd reactivity of bands to lectin varied among the tissues. Upon pretre atment of blotted filters with Bacillus beta-N-acetylgalactosaminidase or N-glycanase, no lectin binding was observed. WFA-agarose column ch romatography of oligosaccharides released by hydrazinolysis from membr ane glycoproteins of bovine tissues except for intestine revealed that a few to 18% of the released oligosaccharides bind and are eluted fro m the column with 100 mM N-acetylgalactosamine. These results indicate that many glycoproteins from a variety of bovine tissues contain N-li nked sugar chains with GalNAc beta 1 --> 4GlcNAc structure, suggesting a wider occurrence of this glycosylation in bovine tissues. (C) 1998 Elsevier Science B.V.