IMMUNOCHEMICAL PROPERTIES OF A 60 KDA CELL SURFACE-ASSOCIATED HEAT SHOCK-PROTEIN (HSP60) FROM HELICOBACTER-PYLORI

Western blot analysis (immunoblotting) of cell surface-associated prot eins from Helicobacter pylori confirmed our previous findings that bin ding of human IgG is a common property (among H. pylori strains). puri fication of the IgG-binding proteins (IGBP) was achieved by two purifi cation steps, affinity chromatography on IgG-Sepharose and nickel chel ate affinity chromatography. SDS-PAGE and immunoblotting analysis reve aled a 60 kDa protein with affinity for peroxidase labeled human IgG. Solid phase binding assays showed that IgG binds to an immobilized pro tein (IGBP). The 60 kDa IGBP binds human IgG(1), IgG(3) and IgM. Bindi ng could be inhibited by the kappa chain of the human IgG, but not wit h its Fc fragment, nor with IgA or IgM. In addition, rabbit polyclonal antibodies raised against the 60 kDa IGBP blocked IgG binding. Monocl onal antibodies, specific to the Hsp60 heat shock protein of H. pylori recognized the 60 kDa IGBP as revealed by immunoblotting analysis, bo th in crude preparations and in the purified fractions.