FIGURE 2.

A. pleuropneumoniae NGT is an inverting glycosyltransferase with specificity for UDP-glucose. A, ¹³C-¹H correlations in an HSQC spectrum of TAMRA-DANYTK-Glc. Signals originating from the covalently linked glucose are shown in purple. The asterisk denotes signals from an impurity of the original peptide. B, ¹H-¹H TOCSY spectrum recorded with a mixing time of 80 ms and four transients. C, Tricine/SDS-PAGE analysis of glycosylation products. TAMRA-labeled peptides were incubated with NGT and different UDP-monosaccharide donors in the presence or absence of EDTA. D, MALDI-MS analysis of the TAMRA-labeled peptide (upper panel) in the presence of NGT and UDP-glucose (middle panel) or UDP-galactose (lower panel).