First evidence for a covalent linkage between enterobacterial common antigen and lipopolysaccharide in Shigella sonnei phase II ECALPS.

Abstract

VOLUME 289 (2017) PAGES 2745–2754 There was an error in the structure of Shigella sonnei phase II ECALPS. The anomeric configuration of residue J should be assigned as a β anomer [→4)-β-d-GlcpNAc-(1→] based on its chemical shifts (Tables 1 and 2) and JH1,C1 (162 Hz). The correction results in an inverted anomeric configuration of the d-GlcNAc residue in the first ECA unit linked to the core oligosaccharide, whereas an α-configuration is characteristic for polymeric chain (Fig. 3). Chemical shifts of the residue J were in agreement with predictions carried out by the CASPER program (http://www.casper.organ.su.se/casper/), 1Please note that the JBC is not responsible for the long-term archiving and maintenance of this site or any other third party-hosted site. where professor Göran Widmalm is kindly acknowledged for the error identification (1.Lundborg M. Widmalm G. Structure analysis of glycans by NMR chemical shift prediction.Anal. Chem. 2011; 83 (21280662): 1514-151710.1021/ac1032534Crossref PubMed Scopus (150) Google Scholar, 2.Jansson P.E. Stenutz R. Widmalm G. Sequence determination of oligosaccharides and regular polysaccharides using NMR spectroscopy and a novel Web-based version of the computer program CASPER.Carbohydr. Res. 2006; 341 (16564037): 1003-101010.1016/j.carres.2006.02.034Crossref PubMed Scopus (82) Google Scholar). This correction does not affect the general results and conclusions of this work.Table 11H and 13C NMR chemical shifts of fraction IV containing core OS substituted by ECA trisaccharide ([ECA]-dLOS) isolated from S. sonnei phase II LOSResidueDescriptionChemical shift (ppm)H-1/C-1H-2/C-2H-3(H3ax,eq)/C-3H-4/C-4H-5/C-5H-6a, H-6b/C-6H-7a, H-7b/C-7 (NHAc)H-8a, H-8b/C-8 [C(O)]A→5)-α-KdopNDaND, not determined.−/96.3(1.90, 2.25)/34.14.11/66.34.17/73.33.69/69.73.80/72.63.47, 3.93/64.7B→3)-l-α-d-Hepp4PPEtn-(1→5.20/100.14.01/71.64.08/78.54.61/72.34.22/72.04.10/69.33.72, 3.72/63.8C→3,7)-l-α-d-Hepp4P-(1→5.10/103.54.38/70.64.12/79.84.40/69.43.80/73.24.23/68.53.58, 3.75/68.4Dl-α-d-Hepp-(1→4.98/100.23.93/70.73.87/71.43.84/66.93.61/71.94.04/69.53.65, 3.72/63.7E→3)-α-d-Glcp-(1→5.20/102.03.66/71.04.07/76.73.77/71.23.91/73.13.79,3.92/60.5F→2,3)-α-d-Glcp-(1→5.80/95.33.87/73.34.17/78.73.56/68.74.10/71.93.78,3.95/61.0F′bResidue F′ is a variant of residue F present in the core OS that is devoid of ECA trisaccharide.→2,3)-α-d-Glcp-(1→5.81/95.13.88/73.34.19/78.83.57/68.74.11/72.03.79,3.96/61.0G→2)-α-d-Galp-(1→5.61/92.13.98/73.24.19/68.93.98/70.74.13/72.03.74,3.74/61.9Hα-d-Galp-(1→5.31/96.63.85/69.03.95/70.13.99/70.14.13/72.03.75,3.75/61.9I→3)-β-d-Glcp-(1→4.73/103.13.39/73.63.68/85.43.49/68.93.44/76.33.72,3.89/61.4I′cResidue I′ is a terminal residue I present in the core OS that is devoid of ECA trisaccharide.β-d-Glcp-(1→4.75/103.13.33/73.93.51/76.63.40/70.43.45/76.63.73,3.91/61.4J→4)-β-d-GlcpNAc-(1→4.78/102.33.75/56.33.74/72.73.68/79.53.54/75.23.86,3.70/60.9(2.03/23.0)[175.5]K→4)-β-d-ManpNAcA-(1→4.93/99.74.49/54.24.07/73.23.82/74.83.86/77.2−/175.1(2.07/22.6)[176.2]Lα-d-Fucp4NAc-(1→5.35/99.53.64/69.34.00/69.14.20/54.64.18/66.51.06/16.2(2.07/22.6)[176.3]PPEtn4.20/63.13.29/40.7a ND, not determined.b Residue F′ is a variant of residue F present in the core OS that is devoid of ECA trisaccharide.c Residue I′ is a terminal residue I present in the core OS that is devoid of ECA trisaccharide. Open table in a new tab Table 2Selected inter-residue NOE and 3JH,C connectivities from the anomeric atoms of ([ECA]-dLOS) dodecasaccharide isolated from S. sonnei phase II LOSResidueDescriptionAtom δH/δC (ppm)Connectivity toInter-residue atom/residueδCδHB→3)-l-α-d-Hepp4PPEtn-(1→5.20/100.1−4.17aValue represents NOE connectivities only.H-5 of AC→3,7)-l-α-d-Hepp4P-(1→5.10/103.578.54.08aValue represents NOE connectivities only.C-3, H-3 of BDl-α-d-Hepp-(1→4.98/100.268.53.59/3.74aValue represents NOE connectivities only.C-7, H-7a, H-7b of CE→3)-α-d-Glcp-(1→5.20/102.0−4.12H-3 of CF→2,3)-α-d-Glcp-(1→5.80/95.3−4.07H-3 of EF′→2,3)-α-d-Glcp-(1→bResidue F′ is a variant of residue F present in the core OS that is devoid of ECA trisaccharide.5.81/95.1−4.07H-3 of EG→2)-α-d-Galp-(1→5.61/92.1−3.87aValue represents NOE connectivities only.H-2 of FHα-d-Galp-(1→5.31/96.6−3.97aValue represents NOE connectivities only.H-2 of GI→3)-β-d-Glcp-(1→4.73/103.178.74.17H-3 of FI′β-d-Glcp-(1→cResidue I′ is a terminal residue I present in the core OS that is devoid of ECA trisaccharide.4.75/103.178.84.19H-3 of F′J→4)-β-d-GlcpNAc-(1→4.78/102.385.33.68H-3 of IK→4)-β-d-ManpNAcA-(1→4.93/99.779.43.69aValue represents NOE connectivities only.H-4 of JLα-d-Fucp4NAc-(1→5.35/99.574.73.81H-4 of Ka Value represents NOE connectivities only.b Residue F′ is a variant of residue F present in the core OS that is devoid of ECA trisaccharide.c Residue I′ is a terminal residue I present in the core OS that is devoid of ECA trisaccharide. Open table in a new tab