The binding of decomposition products of UDP-galactose to the microsomes and polyribosomes isolated from rat liver.
UDP-D-[U-14C]galactose is decomposed to [U-14C]galactose-1-phosphate and [U-14C]galactose by rat liver microsomal and crude polyribosomal fractions, under conditions commonly used to assay of glycosyltransferase activities. UDP-D-[U-14C]galactose, at neutral pH, is also chemically degraded to the [U-14C]galactose-1,2-cyclic phosphate. The 1,2-cyclic phosphate derivative of galactose also exists in the commercial UDP-D-[U-14C]galactose. It is a very important finding that products of the UDP-D-[U-14C]galactose decomposition are tightly, although nonenzymatically, bound to tested subcellular fractions and may create a false impression of protein glycosylation. The application of controls containing all radioactive substances present in suitable samples is recommended in order to avoid incorrect interpretations of the results.
Kopacz-Jodczyk
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T
Department of General and Organic Chemistry, Institute of Chemistry, Medical School, Białystok, Poland.
Gałasiński
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W
D000818:Animals; D002250:Carbon Radioisotopes; D005690:Galactose / Q000378:metabolism; D005695:Galactosephosphates / Q000378:metabolism; D006023:Glycoproteins / Q000096:biosynthesis; D006031:Glycosylation; D066298:In Vitro Techniques; D008862:Microsomes, Liver / Q000378:metabolism*; D011132:Polyribosomes / Q000378:metabolism*; D051381:Rats; D014531:Uridine Diphosphate Galactose / Q000378:metabolism*; D014539:Uridine Diphosphate Sugars / Q000378:metabolism*
D002250:Carbon Radioisotopes; D005695:Galactosephosphates; D006023:Glycoproteins; D014539:Uridine Diphosphate Sugars; C029973:galactose-1-phosphate; D014531:Uridine Diphosphate Galactose; D005690:Galactose