UDP-Glo Glycosyltransferase Assay
The UDP-Glo Glycosyltransferase Assay is a bioluminescent assay for detecting the activity of glycosyltransferases that use UDP-sugars as donor substrates and release UDP as a product. Glycosylation reactions catalyzed by glycosyltransferases are central to many biological processes, including cell:cell interactions, cell signaling and bacterial cell wall biosynthesis. Glycosyltransferases transfer sugar from a nucleotide-glycosyl donor (e.g., UDP-Galactose, UDP-Glucose, UDP-GlcNAc, UDP-GalNAc and UDP-Glucuronic Acid) to an acceptor molecule. In a glycosyltransferase reaction, the UDP moiety is released as a product; therefore, an assay that detects UDP would be suitable for monitoring the activity of the majority of glycosyltransferases. The UDP-Glo Glycosyltransferase Assay is a homogeneous, single-reagent-addition method to rapidly detect UDP formation in glycosyltransferase reactions. After the glycosyltransferase reaction, an equal volume of UDP Detection Reagent is added to simultaneously convert the UDP product to ATP and generate light in a luciferase reaction. The light generated is detected using a luminometer (Figure 1). Luminescence can be correlated to UDP concentration by using an UDP standard curve. This assay is intended for use with purified glycosyltransferases that use UDP-sugar as a donor substrate and cannot be used with whole cells or cell extract. However, glycosyltransferases can be purified from cell extract using immunoprecipitation or affinity tag pull down then used in the UDP-Glo Glycosyltransferase Assay. Note: The UDP-Glo Glycosyltransferase Assay kits have changed from their original component configuration. The UDP-Glo Solution, a component of the original kits, was replaced with 1) UDP-Glo Enzyme and 2) Enzyme Dilution Buffer. The technical manual (#TM413) has instructions for preparing the UDP Detection Reagent. Also, note the change in the kit storage temperature from -20°C to ≤65°C.