Synthesis of Glycan Chemical Probes

Organic chemicals and anti-FLAG antibodies were purchased from Sigma-Aldrich. H. pylori strain G27^{51 (link)} was a gift of Manuel Amieva (Stanford University), and M. smegmatis strain Mc²155::otsA treS treY^{52 (link)} was a gift from Peter Woodruff (University of Southern Maine). Bacterial cells (C. jejuni ATCC 33560; B. thailandensis ATCC 700388; R. solanacearum ATCC 33291* (*incorrectly cataloged as C. jejuni; species confirmed as R. solanacearum by 16S ribosomal RNA sequencing); B. fragilis ATCC 23745; P. aeruginosa ATCC 39324) and MDCK cells (ATCC CCL-34) were purchased from ATCC and grown according to the supplier’s instructions. Ac₄GlcNAc (1), Ac₄GlcNAz (2), Ac₄GalNAz and Phos-FLAG were synthesized as previously described.^{19 ,53} Ac₃6AzGlcNAc (3)^{42 (link)} was kindly provided by Matthew Pratt (University of Southern California). Ac₃FucNAz (4), Ac₂Bac-diNAz (5), and Ac₂DATDG-diNAz (6) were synthesized using standard organic chemistry procedures and characterized by standard techniques including ¹H and ¹³C NMR spectroscopy and mass spectrometry. Ac₃FucNAz (4), Ac₂Bac-diNAz (5), and Ac₂DATDG-diNAz (6) were purified using flash silica gel chromatography.