Galactosyltransferase activity

T r) seeds [10]. O gives brown, whereas recessive o gives a red-brown phenotype. Preliminary analysis reveals the anthocyanin content of red-brown seed coats to differ from brown by the presence of 3-0-galactosides of cyanidin and delphini-din (Fig. 4.2). An enzyme with minor 3-0-galactosyltransferase activity has been identified [26], but it remains to be determined whether genetic differences in this gene account for red-brown versus brown seed coat color. 

Glycolipids Galactosyltransferase Activities in Mouse and Human Tumor Cells... 

Glycoprotein Galactosyltransferase Assays. In order to further investigate the effects of TPA and RA on glycoconjugate metabolism, UDP-galactose DSG-fetuin galactosyltransferase activity was assayed. Table II shows the results of this study. The effects of TPA and RA on... 

Table II. The Effect of Various Compounds Implicated in the 2-Stage Theory of Carcinogenesis on UDP-galactose DSG-fetuin Galactosyltransferase Activity in Human Epithelial Carcinoma (KB) Cells...

CONDITION GALACTOSYLTRANSFERASE ACTIVITY (nmoles/mg protein/hr) % CONTROL... 

Measurement of UDP-Gal lactosylceramide galactosyltransferase Activity in Normal and Mutant Cells... 

Uridine diphosphate galactose lactosylceramide galactosyltransferase activity in cultured normal and familial hypercholesterolemic human fibroblasts... 

More recently, Hymes and Mullinax (1984) introduced the use of HPLC in the determination of galactosyltransferase activity. This method... 

Iodination was explored further by Chandler et al. (1980) with lacto-peroxidase, which catalyzes iodination of Tyr with I. Further, they found that galactosyltransferase was inactivated by Al-acetylimidazole. This observation was consistent with an essential role of Tyr for activity. However, this reagent also affects the amino groups of Lys residues. Differentiation between these possibilities is afforded by the fact that deacetylation with hydroxylamine will occur for the Tyr derivative, but not for the Lys derivative. Since only about 40% of the activity could be recovered by deacetylation, Lys could also have been involved. Note that this indication is the second for the implication of a Lys residue with galactosyltransferase activity (see Powell and Brew, 1976c). 

D-galactosamine 3-P-D-galactosyltransferase activity synthesizing 0-glycan core 1 is controlled by the amino acid sequence... 

Abdul-Rahman B, Ailor E, Jarvis D, Betenbaugh M, Lee YC. Beta-(1- > 4)-Galactosyltransferase activity in native and engineered insect cells measured with time-resolved europium fluorescence. Carbohydr Res. 2002 337 2181-2186. 

Shur, B.D. and Hall, N.D. (1982b). Sperm surface galactosyltransferase activities during in vitro capacitation. J. Cell Biol. 95 567-573. 

The j8-galactosidase from the Pencillium simplicissimum isolated from soil has high galactosyltransferase activity Synthesis of galactoohgosaccharides from 3 to 4 units of monosaccharide. When monosaccharides are present in the reaction system, the transfer activity of the enzyme will be inhibited, so only by the enzyme from P. simplicissimum cultured under the non-optimum hydrolysis conditions, galactooligosaccharide production can reach the maximum. For example, the lactose solution (concentration of 60%) incubated at pH 6.5 and 50 C obtained the maximum conversion rate. The product composition was 30.5% galacto-ohgosaccharide, 27.5% residual lactose and 42% free monosaccharides. 

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