1. NMR Spectra of YS1-HP2627 Collected at 25°C on a Varian VNMRS 800 Instrument.(A) HSQC spectrum.
NMR Spectra of YS1-HP2627 Collected at 25°C on a Varian VNMRS 800 Instrument.(A) HSQC spectrum. The inset is the enlarged anomeric region. Signals A and B were identified as the anomeric C/H of α-l-Araf residues; C, as the anomeric C/H of the 1,3-galactan backbone Gal (Galbb); D, as the anomeric C/H of the AG side chain Gal (Galsc); E, as the anomeric C/H of β-d-Xylp residues; F, as the anomeric C/H of β-d-GlcAp; G, as the C/H-6 of α-l-Rhap residues (the signal of G is folded in this HSQC spectrum due to the small 13C spectral width used; as such, 80 ppm should be subtracted from the respective 13C chemical shifts); H, as the C/H-4 of 4-Xylp.(B) COSY spectrum (partial) collected at 25°C. The correlation between Hyp H-3ax and Hyp H-3ex is labeled.(C) TOCSY spectrum identified the protons of Xyl residues, GlcA, and the Gal residue attached to Hyp. The labels X1 to X5 represent H-1 to H-5 of 4-Xyl; GA3 and GA5 represent H-3 and H-5 of GlcA; and G12 represents H-2 of Gal attached to Hyp. A similar pattern was also observed in TOCSY recorded on YS2-HP2627.(D) NOESY spectrum (partial) (mixing time 100 ms). Cross-peak A shows the NOE between Xyl H-1 to Ara H-5, which established the β-d-Xylp-1→5-α-l-Araf linkage; cross-peak B shows NOEs between Galbb H1 and Galbb H3, suggesting the Galbb-1→3-Galbb linkage; cross-peak C (NOE between Galbb H1 and Galbb H6) supports the Galbb-1→6-Galbb linkage; NOEs in D suggest the Galsc-1→6-Galbb linkage.(E) HMQC spectrum (partial) collected at 30°C. Signal A represents the anomeric 1H/13C signals of 2-α-l-Rha, B the anomeric 1H/13C signals of α-d-GalA, and C to F the anomeric 1H/13C signals of α-l-Araf. Hyp-glycoside YS1-HP2627 produced by SEC chromatography of base hydrolyzed YS1 as depicted in Figure 1C.
Li Tan et al. Plant Cell 2013;25:
©2013 by American Society of Plant Biologists