ISSN:
1434-4726
Schlagwort(e):
N-Acetylglucosamine
;
Sugar-binding site
;
Middle ear mucosa
;
Guinea pig
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Summary The distribution of sugar-binding sites was analyzed in Lowicryl K4M-embedded guinea pig middle ear mucosa. Four neoglycoproteins and a glycoprotein were used as probes: N-acetyl-d-glucosamine (GlcNAc), d-mannose, N-acetyl-d-galactosamine, or l-fucose carrying bovine serum albumin (BSA) and asialofetuin with terminal d-galactosyl sugar residues. Each probe was then labelled with 15 nm colloidal gold. Incubation of ultrathin sections with gold-labelled p-aminophenyl N-acetyl-β-d-glucosaminide-BSA (GlcNAc/BSA/gold) led to binding on mucosal cilial, microvilli, rough endoplasmic reticulum, mitochondria, and nuclei. No binding occurred with asialofetuin or neoglycoproteins containing mannose, N-acetylgalactosamine or fucose. Various control experiments showed that specificity of G1cNAc/BSA/gold binding was directed towards N-acetylglucosaminyl residues expressed on the neoglycoprotein. Competitive sugar inhibition with GlcNAc and its derivatives suggested that the strong affinity for GlNAc-binding sites took place in a complex formation with sugar residues bound to a carrier protein. The existence of a hydrophobic region close to the sugar-binding site was also suggested.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00188382
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