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Structural studies of the O-antigen polysaccharide from Escherichia coli TD2158 having O18 serogroup specificity and aspects of its interaction with the tailspike endoglycosidase of the infecting bacteriophage HK620

  • We have analyzed the O-antigen polysaccharide of the previously uncharacterized Escherichia coli strain TD2158 which is a host of bacteriophage HK620. This bacteriophage recognizes and cleaves the polysaccharide with its tailspike protein (TSP). The polysaccharide preparation as well as oligosaccharides obtained from HK620TSP endoglycosidase digests were analyzed with NMR spectroscopy. Additionally, sugar analysis was performed on the O-antigen polysaccharide and MALDI-TOF MS was used in oligosaccharide analysis. The present study revealed a heterogeneous polysaccharide with a hexasaccharide repeating unit of the following structure: alpha-D-Glcp-(1 -> 6) vertical bar vertical bar 2)-alpha-L-Rhap-(1 -> 6)-alpha-D-Glcp-(1 -> 4)-alpha-D-Galp-(1 -> 3)-alpha-D-GlcpNAc- (1 ->vertical bar beta-D-Glcp/beta-D-GlcpNAc-(1 -> 3) A repeating unit with a D-GlcNAc substitution of D-Gal has been described earlier as characteristic for serogroup O18A1. Accordingly, we termed repeating units with D-Glc substitution at D-Gal as O18A2. NMR analyses ofWe have analyzed the O-antigen polysaccharide of the previously uncharacterized Escherichia coli strain TD2158 which is a host of bacteriophage HK620. This bacteriophage recognizes and cleaves the polysaccharide with its tailspike protein (TSP). The polysaccharide preparation as well as oligosaccharides obtained from HK620TSP endoglycosidase digests were analyzed with NMR spectroscopy. Additionally, sugar analysis was performed on the O-antigen polysaccharide and MALDI-TOF MS was used in oligosaccharide analysis. The present study revealed a heterogeneous polysaccharide with a hexasaccharide repeating unit of the following structure: alpha-D-Glcp-(1 -> 6) vertical bar vertical bar 2)-alpha-L-Rhap-(1 -> 6)-alpha-D-Glcp-(1 -> 4)-alpha-D-Galp-(1 -> 3)-alpha-D-GlcpNAc- (1 ->vertical bar beta-D-Glcp/beta-D-GlcpNAc-(1 -> 3) A repeating unit with a D-GlcNAc substitution of D-Gal has been described earlier as characteristic for serogroup O18A1. Accordingly, we termed repeating units with D-Glc substitution at D-Gal as O18A2. NMR analyses of the polysaccharide confirmed that O18A1- and O18A2-type repeats were present in a 1:1 ratio. However, HK620TSP preferentially bound the D-GlcNAc- substituted O18A1-type repeating units in its high affinity binding pocket with a dissociation constant of 140 mu M and disfavored the O18A2-type having a beta-D-Glcp-(1 -> 3)-linked group. As a result, in hexasaccharide preparations, O18A1 and O18A2 repeats were present in a 9: 1 ratio stressing the clear preference of O18A1- type repeats to be cleaved by HK620TSP.show moreshow less

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Metadaten
Author:Mona V. Zaccheus, Nina Kristin Bröker, Magnus Lundborg, Charlotte Uetrecht, Stefanie BarbirzORCiDGND, Goran Widmalm
DOI:https://doi.org/10.1016/j.carres.2012.05.022
ISSN:0008-6215 (print)
Parent Title (English):Carbohydrate research
Publisher:Elsevier
Place of publication:Oxford
Document Type:Article
Language:English
Year of first Publication:2012
Year of Completion:2012
Release Date:2017/03/26
Tag:Endoglycosidase; Escherichia coli; Lipopolysaccharide; Mass spectrometry; NMR; Tailspike
Volume:357
Issue:8
Pagenumber:8
First Page:118
Last Page:125
Funder:Swedish Research Council; Knut and Alice Wallenberg Foundation; Deutsche Forschungsgemeinschaft [BA 4046/1-1]
Organizational units:Mathematisch-Naturwissenschaftliche Fakultät / Institut für Biochemie und Biologie
Peer Review:Referiert