Characterization of the oligosaccharide component of microsomal beta-glucuronidase from rat liver.
The oligosaccharides of microsomal beta-glucuronidase were analysed by gel permeation and weak anion exchange chromatography following hydrazine release. N-linked glycans, constituted 80% of the total glycan pool and were mainly of the tri- and biantennary complex type with or without core and arm fucose. The major oligosaccharide, that comprised 30.6% of all the species analysed, was structurally identified by reagent array analysis method and found to be a triantennary complex structure, Galbeta1,4GlcNAcbeta1,2Manalpha1,6(3)(Galbeta1,4GlcNAcbeta1,4(Galbeta1,4GlcNAcbeta1,2) Manalpha1,3(6))Manbeta1,4GlcNAcbeta1,4 GlcNAc. O-Linked glycans comprised 20% of the total glycan pool, the major species being Galbeta1,3GalNAc. All of the N- and O-linked glycans were charged. Most of the negative charge was due to sialic acid (85.0%) with the remainder being phosphate present as phosphomonoesters (7.3%) and phosphodiesters (5%). This is the first report of O-linked carbohydrate chains in microsomal beta-glucuronidase. The presence of O-linked glycans and branched N-linked glycans in a microsomal enzyme, in relation to the current view of glycosyltransferase compartmentalization in the Golgi is discussed.
Hoja-Łukowicz
Dorota
D
Department of Animal Physiology, Institute of Zoology, Jagiellonian University, 6 Ingardena Street, 30 060 Kraków, Poland. hoja@zuk.iz.uj.edu.pl
Butters
Terry D
TD
Lityńska
Anna
A
D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002852:Chromatography, Ion Exchange / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods; D004590:Electrophoresis, Paper / Q000379:methods; D005966:Glucuronidase / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D006031:Glycosylation; D006056:Golgi Apparatus / Q000378:metabolism; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis / Q000737:chemistry*; D011134:Polysaccharides / Q000032:analysis / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar
D009844:Oligosaccharides; D011134:Polysaccharides; D005966:Glucuronidase