In vitro synthesis of glucopyranosyl-xylose catalyzed by purified Saccharophagus degradans cellobiose phosphorylase. (A) Reactions containing 10 mM xylose and 10 mM G1P, along with 20 nM purified SdCBP in 20 mM 2-(N-morpholino) ethanesulfonic acid, pH 6.0 solution were incubated at 37°C for 12 hours. The purified SdCBP was omitted from the negative control. A product signal (eluted at 4.9 minutes), along with decreases in xylose and G1P (showed in the insert with different scale) signals, were observed only when SdCBP was provided in the reaction. Chromatograms are displayed with 2 minute-offset between samples. (B) Structure of the GX dimer. G1P, glucose-1-phosphate; GX, 4-O-β-D-glucopyranosyl-D-xylose; SdCBP, Saccharophagus degradans cellobiose phosphorylase.