Figure 6.

Detection of sugar modifications on WTA and LTA using ¹H NMR. A and B, NMR spectra of WTA derived from L. monocytogenes 10403S (WT) (A) and the lmo1079 mutant (B). Peaks of nonexchangeable protons were assigned to the different WTA components according to previously published spectra (45, 74, 78). The different peaks for the protons and acetyl group of GlcNAc are labeled with 1H, 4H, and Ac, respectively. One representative spectrum from three independent experiments is shown. C and D, NMR spectra of LTA derived from L. monocytogenes 10403S (WT) (C) and the lmo1079 mutant strain (D). Peaks of nonexchangeable protons were assigned to the different LTA components using previously published spectra and are highlighted in colored boxes (29, 37–39). Gray boxes indicate residual citrate, a component of the buffer used for LTA purification. The spectra for lmo1079 are representative of three independent experiments. LTA of strain 10403S was isolated once as a control.