Fig. 4.

Conversion of UDP-d-glucose by Agl3 in the absence of sulfite (a) RP-HPLC analysis of the conversion of UDP-d-glucose to the UDP-d-glucose-5,6-ene intermediate (arrow at 3.8 min) in the presence of Agl3 (graph 1). In the negative control experiment (absence of Agl3; graph 2), no conversion was observed. b NMR expansion plot of an edHSQC spectrum of the mixture of UDP-d-glucose (major component) and UDP-d-glucose-5,6-ene (minor component from the enzymatic conversion). The inset (b) shows an expansion plot of the ³¹P NMR spectrum of the mixture displaying the intact diphosphate linkages of both compounds. c ESI–MS analysis of UDP-d-glucose-5,6-ene