The formation of mono-N-acetylhexosamine derivatives of dolichol diphosphate by pig liver microsomal fractions.
Incubation of pig liver microsomal preparations with UDP-N[U-14C]acetylglucosamine yields a 14C-labelled lipid. The requirement for Mn2+, the pH optimum, time-dependence and the reversibility by UMP of the transferase are reported. Evidence is presented in favour of the lipid being a mixture of dolichol diphosphate N-[14C]acetylglucosamine and dolichol diphosphate N-[14C]acetylmannosamine. Available data suggest that the epimerization takes place while the hexosamine is bound in this lipid-soluble form. The N-acetylmannosamine appeared not be be released into the medium. The subfractionation of the microsomal fraction to separate transferase activity from membrane-bound beta-N-acetylglucosaminidase activity is also reported.
D000818:Animals; D004286:Dolichols / Q000031:analogs & derivatives / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008345:Manganese; D008862:Microsomes, Liver / Q000378:metabolism*; D013552:Swine; D013997:Time Factors; D014500:Uracil Nucleotides / Q000378:metabolism; D014537:Uridine Diphosphate N-Acetylglucosamine / Q000378:metabolism*; D014539:Uridine Diphosphate Sugars / Q000378:metabolism*
D004286:Dolichols; D014500:Uracil Nucleotides; D014539:Uridine Diphosphate Sugars; D008345:Manganese; D014537:Uridine Diphosphate N-Acetylglucosamine