The presence of N-acetyllactosamine and lactose: beta (1-3)N-acetylglucosaminyltransferase activity in human urine.
Normal human urine was found to contain beta (1-3)N-acetylglucosaminyltransferase catalyzing the transfer of N-acetylglucosamine from UDP-GlcNAc to N-acetyllactosamine and lactose. Lacto-N-tetraose which carries the terminal Gal beta (1-3)GlcNAc structure was a poor acceptor. The product of the transferase reaction with N-acetyllactosamine as acceptor was identified by methylation analysis as GlcNAc beta (1-3)Gal beta (1-4)GlcNAc. The beta-linkage of the GlcNAc in the synthesized trisaccharide was confirmed by the action of the specific beta-N-acetylhexosaminidase. The enzyme requires Mn2+ ions for its activity, shows a broad pH optimum from 7 to 9, and appears to have a molecular weight of about 200,000 as estimated by Sephadex gel filtration.
Takeya
A
A
Hosomi
O
O
Kogure
T
T
D005964:Glucosyltransferases / Q000652:urine*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007785:Lactose / Q000378:metabolism; D008970:Molecular Weight; D017351:N-Acetylglucosaminyltransferases; D013379:Substrate Specificity; D014539:Uridine Diphosphate Sugars / Q000378:metabolism
D014539:Uridine Diphosphate Sugars; D005964:Glucosyltransferases; D017351:N-Acetylglucosaminyltransferases; C037649:N-acetyllactosaminide beta-1,6-N-acetylglucosaminyltransferase; D007785:Lactose