The scientists made their discovery by studying the detailed molecular structure of the enzymes and the UDP-galactose
GmGolS catalyzes the synthesis of fagopyritol B1 from o-chiro-inositol and UDP-galactose
(Obendorf et al., 2004).
The gold standard red cell GALT assay requires measurement of radioisotope exchange between UDP-galactose to UDP glucose, followed by a secondary linking enzyme reaction and chromatographic separation of the radiolabeled products before scintillation counting (6).
The enzymatic assay is performed offline, and the product, [sup.13]C-labeled UDP-galactose, is separated by a short UPLC run, ionized by negative ion electrospray ionization, and monitored by multiple reaction monitoring with appropriate isotope-labeled internal standards.
The molecules, called "synthetic UDP-galactose
derivatives", may also stop infectious bacteria spreading.
In the GALE assay, enzymatic conversion from UDP-galactose to UDP-glucose is detected either by radioactive (9) or nonradioactive assay, with substrates and products separated and quantified by HPLC (11).
The stock solutions containing 10 mmol/L [[sup.13]C6]galactose-1-phosphate and 10 mmol/L UDP-galactose were prepared in HPLC-grade water and stored at -70[degrees]C.
Galactosylceramide is galactosylated by a galactosyltransferase (UDP-galactose:ceramide galactosyltransferase) found exclusively in the ER, whereas the UDP-Gal transporter has mainly a Golgi localization.
Human and Drosophila UDP-galactose transporters transport UDP-N-acetylgalactosamine in addition to UDP-galactose.
Transferrin hypoglycosylation in these patients may be attributable to direct inhibition of galactosyltransferase activity by the accumulated galactose 1-phosphate or to an effect on the formation of UDP-galactose
, the donorsubstrate in the reaction (27).
Gal-1-P accumulates in the tissues of patients who are unable to convert it to UDP-galactose
because of a deficiency of GALT.
For our studies into the role of the hexosamine pathway in type 2 diabetes mellitus, we were interested in a method to assess UDP-galactose
(UDP-Gal), UDP-glucose (UDP-Glc), UDP-GalNAc, and UDP-G1cNAc in small samples of human muscle tissue, e.g., percutaneous muscle biopsies.