Fig. 2: B. burgdorferi peptidoglycan glycan strands contain the trisaccharide G-G-anhM.
From: The unusual cell wall of the Lyme disease spirochaete Borrelia burgdorferi is shaped by a tick sugar
a, LC–MS chromatogram of unlabelled B. burgdorferi 5A11 peptidoglycan. Total ion chromatogram is shown in black with an unlabelled and [1-¹³C]G-G-anhM muropeptide overlaid in pink and blue, respectively. b, LC–MS chromatogram of [1-¹³C]GlcNAc metabolically labelled B. burgdorferi 5A11 peptidoglycan producing a mass shift corresponding to a G-G-anhM muropeptide. B. burgdorferi was cultured with unlabelled GlcNAc or [1-¹³C]GlcNAc before peptidoglycan purification and LC–MS analysis. The proposed G-G-anhM species 1,053 m/z in unlabelled peptidoglycan and the shifted mass to the predicted 1,056 m/z when labelled with [1-¹³C]GlcNAc are shown. c, The ¹³C-labelled NMR of the anomeric region of 1-¹³C-labelled B. burgdorferi peptidoglycan and an N,N′,N′′-triacetylchitotriitol reference standard with the highlighted region (light blue) indicating a putative chemical shift for the non-reducing-end anomeric carbon. d, A comparative muropeptide analysis of peptidoglycan isolated from three clonal derivatives of B. burgdorferi and one strain of B. hermsii. Three laboratory strains of B. burgdorferi, two fully infectious clones of the B31-type strain (5A11, green; 5A3, purple) and non-infectious (n.i.) derivative of 5A3 (blue), as well as B. hermsii (yellow) were cultured to mid-log, peptidoglycan was purified, digested and muropeptide profiles compared by LC. All samples contained similar levels of G-G-anhM muropeptides (*).
