Fig. 3.

HR-MAS [¹H]NMR analyses of the CPS of C. jejuni 11168 H and several mutants. (a) C. jejuni 11168 H; (b) Cj1426; (c) Cj1427; (d) Cj1430; (e) Cj1432; (f) Cj1434; (g) Cj1438; (h) Cj1440; (i) Cj1441; (j) Cj1442. The anomeric protons of the CPS correspond to (A) 3,6-di-O-methyl-d-glycero-α-l-glucoheptose, (B) β-d-ribose, (C) α-d-glucuronic acid amidated predominantly with 2-amino-2-deoxyglycerol and (D) β-d-GalfNAc. Other labelled proton resonances include the phase variable O-methyl groups linked to heptose and the phosphoramidate (MeOPN) modifications linked to heptose and GalfNAc. In the acapsular mutants, the anomeric resonances from the free oligosaccharides derived from the N-glycan pathway are visible and labelled.²² The top right corner depicts the structure of the repeating subunit of the capsule of 11168 H.