Helicobacter pylori and complex gangliosides.

• Recognition of sialic acid-containing glycoconjugates by the human gastric pathogen Helicobacter pylori has been repeatedly demonstrated. To investigate the structural requirements for H. pylori binding to complex gangliosides, a large number of gangliosides were isolated and characterized by mass spectrometry and proton nuclear magnetic resonance. Ganglioside binding of sialic acid-recognizing H. pylori strains (strains J99 and CCUG 17874) and knockout mutant strains with the sialic acid binding adhesin SabA or the NeuAcalpha3Galbeta4GlcNAcbeta3Galbeta4GlcNAcbeta-binding neutrophil-activating protein HPNAP deleted was investigated using the thin-layer chromatogram binding assay. The wild-type bacteria bound to N-acetyllactosamine-based gangliosides with terminal alpha3-linked NeuAc, while gangliosides with terminal NeuGcalpha3, NeuAcalpha6, or NeuAcalpha8NeuAcalpha3 were not recognized. The factors affecting binding affinity were identified as (i) the length of the N-acetyllactosamine carbohydrate chain, (ii) the branches of the carbohydrate chain, and (iii) fucose substitution of the N-acetyllactosamine core chain. While the J99/NAP(-) mutant strain displayed a ganglioside binding pattern identical to that of the parent J99 wild-type strain, no ganglioside binding was obtained with the J99/SabA(-) mutant strain, demonstrating that the SabA adhesin is the sole factor responsible for the binding of H. pylori bacterial cells to gangliosides.

Keyword

Adhesins

Bacterial

genetics

physiology

Animals

Bacterial Adhesion

physiology

Binding Sites

Carbohydrate Sequence

Erythrocytes

chemistry

Gangliosides

chemistry

physiology

Genes

Bacterial

Helicobacter pylori

genetics

pathogenicity

physiology

Humans

Kinetics

Molecular Sequence Data

Molecular Structure

Mutation

Nuclear Magnetic Resonance

Biomolecular

Spectrometry

Mass

Electrospray Ionization

Spectrometry

Mass

Fast Atom Bombardment

Adhesins; Bacterial/genetics/physiology

Publication and Content Type

ref (subject category)

art (subject category)