Anion-exchange HPLC chromatograms of oligosaccharide substrates modified by 2OST wild type
and mutant proteins. Two oligosaccharide substrates, compound 3 and
4, were incubated with 2OST proteins in the presence of 35S-labeled PAPS
followed by anion-exchange HPLC analysis. A–C represent chromatograms of the
GlcA-containing substrate incubated with wild type 2OST (red tracing), 2OST R189A,
and 2OST R354A, respectively. D–F represent chromatograms of the
IdoA-containing substrate incubated with wild type 2OST, 2OST R189A, and 2OST R354A, respectively.
Control reactions have no enzyme (blue tracing in both A and
D). For the left column (A–C), the
35S-labeled peak eluted at 32–33 min contains the desired product. The
35S-labeled peak eluted at 38 min is PAPS. * indicates an unidentified peak. For
the right column (D–F), the35S-labeled peak
eluted at 35–36 min is the desired product.