FIGURE 4.

ENPP3-mediated UDP-GlcNAc hydrolysis. The intact and T205A-mutated ENPP3 recombinant proteins were generated and partially purified (see “Experimental Procedures”). A, ion pair reversed phase HPLC profile on the hydrolysate of UDP-GlcNAc by ENPP3. The reaction was carried out by mixing 100 ng of the partially purified intact or T205A-mutated recombinant ENPP3 with 20 mm UDP-GlcNAc, and the resulting product was analyzed by ion pair reversed phase HPLC, as described under “Experimental Procedures.” The arrows indicate the elution positions of authentic compounds, UMP, UDP-GlcNAc, and UDP. B, deduced reaction of ENPP3-catalyzed hydrolysis of UDP-GlcNAc. GlcNAc-1-P, GlcNAc 1-phosphate.