UDP-glucosamine as a substrate for dolichyl monophosphate glucosamine synthesis.
The sugar nucleotide analogue UDP-glucosamine was found to function as a sugar donor in microsomal preparations of both chick-embryo cells and rat liver, yielding dolichyl monophosphate glucosamine (Dol-P-GlcN). This was characterized by t.l.c. and retention by DEAE-cellulose. Glucosamine was the only water-soluble product released on mild acid hydrolysis. Dol-P-GlcN did not serve as substrate by transferring its glucosamine moiety to dolichol-linked oligosaccharide. Competition experiments between UDP-[3H]glucose and UDP-glucosamine showed Dol-P-[3H]glucose synthesis to be depressed by 56 or 73% in microsomes from chick-embryo cells and rat liver respectively. The concentrations of the UDP-sugars in this experiment were comparable with those occurring in galactosamine-metabolizing liver. These findings suggest that Dol-P-GlcN, formed as a metabolite of D-galactosamine, may interfere with Dol-P-dependent reactions.
W
W
McDowell
G
G
Weckbecker
D O
DO
Keppler
R T
RT
Schwarz
D000818:Animals; D002642:Chick Embryo; D002851:Chromatography, High Pressure Liquid; D005688:Galactosamine / Q000378:metabolism; D005944:Glucosamine / Q000031:analogs & derivatives* / Q000378:metabolism*; D008861:Microsomes / Q000378:metabolism; D008862:Microsomes, Liver / Q000378:metabolism; D009711:Nucleotides / Q000378:metabolism; D011103:Polyisoprenyl Phosphate Monosaccharides / Q000378:metabolism*; D011105:Polyisoprenyl Phosphate Sugars / Q000378:metabolism*; D051381:Rats
D009711:Nucleotides; D011103:Polyisoprenyl Phosphate Monosaccharides; D011105:Polyisoprenyl Phosphate Sugars; C048624:dolichol monophosphate glucosamine; C026712:UDP-glucosamine; D005688:Galactosamine; D005944:Glucosamine