The presence of cell-bound K1 capsule and K1 polysaccharide in culture supernatants was determined in a series of inframe nonpolar core biosynthetic mutants from Escherichia coli KT1094 (K1, R1 core lipopolysaccharide [LPS] type) for which the major core oligosaccharide structures were determined. Cell-bound K1 capsule was absent from mutants devoid of phosphoryl modifications on L-glycero-D-manno-heptose residues (HepI and HepII) of the inner-core LPS and reduced in mutants devoid of phosphoryl modification on HepII or devoid of HepIII. In contrast, in all of the mutants, K1 polysaccharide was found in culture supernatants. These results were confirmed by using a mutant with a deletion spanning from the hldD to waaQ genes of the waa gene cluster to which individual genes were reintroduced. A nuclear magnetic resonance (NMR) analysis of core LPS from HepIII-deficient mutants showed an alteration in the pattern of phosphoryl modifications. A cell extract containing both K1 capsule polysaccharide and LPS obtained from an O-antigen-deficient mutant could be resolved into K1 polysaccharide and core LPS by column chromatography only when EDTA and deoxycholate (DOC) buffer were used. These results suggest that the K1 polysaccharide remains cell associated by ionically interacting with the phosphate-negative charges of the core LPS.

Effects of lipopolysaccharides biosynthesis mutations on K1 polysaccharide association with the Escherichia coli cell surface / N., Jiménez; S. N., Senchenkova; Y. A., Knirel; Pieretti, Giuseppina; Corsaro, MARIA MICHELA; E., Aquilini; M., Regué; S., Merino; J., Tomàs. - In: JOURNAL OF BACTERIOLOGY. - ISSN 0021-9193. - 194:13(2012), pp. 3356-3367. [10.1128/JB.00329-12]

Effects of lipopolysaccharides biosynthesis mutations on K1 polysaccharide association with the Escherichia coli cell surface

PIERETTI, GIUSEPPINA;CORSARO, MARIA MICHELA;
2012

Abstract

The presence of cell-bound K1 capsule and K1 polysaccharide in culture supernatants was determined in a series of inframe nonpolar core biosynthetic mutants from Escherichia coli KT1094 (K1, R1 core lipopolysaccharide [LPS] type) for which the major core oligosaccharide structures were determined. Cell-bound K1 capsule was absent from mutants devoid of phosphoryl modifications on L-glycero-D-manno-heptose residues (HepI and HepII) of the inner-core LPS and reduced in mutants devoid of phosphoryl modification on HepII or devoid of HepIII. In contrast, in all of the mutants, K1 polysaccharide was found in culture supernatants. These results were confirmed by using a mutant with a deletion spanning from the hldD to waaQ genes of the waa gene cluster to which individual genes were reintroduced. A nuclear magnetic resonance (NMR) analysis of core LPS from HepIII-deficient mutants showed an alteration in the pattern of phosphoryl modifications. A cell extract containing both K1 capsule polysaccharide and LPS obtained from an O-antigen-deficient mutant could be resolved into K1 polysaccharide and core LPS by column chromatography only when EDTA and deoxycholate (DOC) buffer were used. These results suggest that the K1 polysaccharide remains cell associated by ionically interacting with the phosphate-negative charges of the core LPS.
2012
Effects of lipopolysaccharides biosynthesis mutations on K1 polysaccharide association with the Escherichia coli cell surface / N., Jiménez; S. N., Senchenkova; Y. A., Knirel; Pieretti, Giuseppina; Corsaro, MARIA MICHELA; E., Aquilini; M., Regué; S., Merino; J., Tomàs. - In: JOURNAL OF BACTERIOLOGY. - ISSN 0021-9193. - 194:13(2012), pp. 3356-3367. [10.1128/JB.00329-12]
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/463465
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 15
  • ???jsp.display-item.citation.isi??? 9
social impact