Fig. 1.

C. neoformans GXM synthetic decasaccharide (GXM10-Ac₃) resonances are resolved through ¹H-¹³C CT-cHSQC and HSQC TOCSY experiments. (A) GXM10-Ac₃ chemical structure contains the M2 motif, a common serotype A GXM RU, and binds strongly to anti-GXM Abs (24). Glycans are color coded as follows: Man (green), Xyl (orange), and GlcA (blue). Transglycosidic ϕ and ψ torsions are denoted on the first three residues. (B) GXM10-Ac₃ ¹H 1D identifiying diagnostic carbohydrate ¹H chemical shift regions. (C and D) Comparison of resolutions achieved by a standard ¹H-¹³C HSQC experiment relative to a CT-cHSQC experiment, with the latter allowing assignments of previously overlapping signals in a few hours for Xyl[II, IV, X]-2 (C) and Xyl[II, IV, VIII]-3 (D). (E) ¹H-¹H cross-peaks between Xyl H1 and H3 obtained from a ¹H-¹³C HSQC TOCSY experiment allow further differentiation between Xyl[II] and Xyl[III] H2-C2 resonances.