Fig. 3.

L. major ugp⁻ mutant present residual UDP-glucose pyrophosphorylase activity despite absence of UGP. (A and B) Whole cell lysates (12 µg/lane) of logarithmic and stationary phase wild-type promastigotes, wild-type amastigotes isolated from mice lesions and ugp⁻ and ugp⁻/UGP promastigotes were subjected to SDS–PAGE and western blotting with anti-UGP serum. (C) Conversion of glucose-1-phosphate (gray) or galactose-1-phosphate (black) into UDP-Glc or UDP-Gal measured in total cell lysates from L. major wild type or the ugp⁻ mutant by a coupled enzymatic assay measuring reduction of NAD by the UDP-Glc dehydrogenase. UDP-glucose 4-epimerase converting UDP-Gal into UDP-Glc was added in assays measuring the activation of galactose-1-phosphate. Each value represents the average of three independent experiments in which measurements were carried out in triplicates