Figure 7.

The 5-Thiomannosides and 5-thiomannose are not converted into GDP-5-thiomannose nor do they prevent the metabolism of nucleotide sugars used in DLO biosynthesis. (A) Representative CE electropherograms obtained from nucleotide sugars extracted from CHO K1 cells grown in the presence of 1, 2 and 4. The identity of peaks was established on the basis of their co-migration with the following standards: CMP-Neu5Ac (i), GDP-Glc, internal standard (ii), UDP-GlcNAc (iii), GDP-Man (iv), GDP-Fuc (v), UDP-Glc (vi), UDP-GalNAc (vii), UDP-Gal (viii) and AMP (ix). Inset is the electropherogram region of 4-treated cells predicted to contain GDP-5-thiomannose (* denotes the position of the synthetically prepared standard). GDP-Glc was added to cell lysates before extraction and the area of this peak was normalized to allow for the (B) calculation of the relative changes in nucleotide sugar levels upon treatment with inhibitors under normal (dark bars) and mannose-supplemented (to 5 mM, light bars) conditions. All data are reported ± standard deviation (n = 3).