Abstract
We found a protein binding non-antibody human IgG in Helicobactor pylori cell wall, when the IgG was enzymically deglycosylated. The protein had the amino acid sequence AEDGAHVAFM. IgG of H. pylori patients also bound to the protein and the IgG lost the sugar chain structure reactivities. These findings indicate that H. pylori binds human IgG without the sugar chains on its cell wall and suggest that H. pylori infection has a relation to the human IgG deglycosylation.