title: Fumarate reductase of Helicobacter pylori--an immunogenic protein.
abstract: An immunogenic protein with an apparent mol. wt of 80 kDa that was recognised by 55% of sera from patients infected with Helicobacter pylori in Western blots was found in butanol extracts of H. pylori membranes. The N-terminal amino-acid sequence of the 80-kDa protein showed 80% identity with the N-terminal sequence of subunit A of the fumarate reductase of Wolinella succinogenes, suggesting the existence of a fumarate reductase in H. pylori. The membrane fraction of H. pylori catalysed succinate oxidation with methylene blue at a specific enzyme activity of 0.06 U/mg of protein. The enzyme was purified by Triton X100 extraction followed by ion-exchange chromatography. The purified enzyme contained an 80-kDa protein which was recognised by rabbit serum raised against subunit A of fumarate reductase of W. succinogenes. A second protein band with a mol. wt of 31 kDa was recognised by rabbit serum raised against subunit B of fumarate reductase of W. succinogenes. Two-dimensional gel electrophoresis demonstrated that the 80- and 31-kDa proteins were subunits of one protein complex. These results indicate that H. pylori contains an enzyme that is very similar to W. succinogenes fumarate reductase. The 80-kDa subunit was recognised in sonicates of all 32 H. pylori strains tested by rabbit antibodies raised against subunit A of fumarate reductase of W. succinogenes, indicating that fumarate reductase is a common protein in H. pylori. The fumarate reductase of H. pylori might enable the bacterium to perform anaerobic respiration in a similar fashion to other anaerobic or facultative bacteria.
authors.affiliation: Department of Medical Microbiology and Immunology, Ruhr-Universität Bochum, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Birkholz
authors.forename: U
authors.initials: U
authors.lastname: Knipp
authors.forename: E
authors.initials: E
authors.lastname: Lemma
authors.forename: A
authors.initials: A
authors.lastname: Kröger
authors.forename: W
authors.initials: W
authors.lastname: Opferkuch
mesh_terms: D000595:Amino Acid Sequence; D000907:Antibodies, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000032:analysis / Q000302:isolation & purification; D015153:Blotting, Western; D000440:Butanols; D004591:Electrophoresis, Polyacrylamide Gel; D016481:Helicobacter Infections / Q000276:immunology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000201:enzymology* / Q000276:immunology; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D008969:Molecular Sequence Data; D013385:Succinate Dehydrogenase / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D000440:Butanols; D007106:Immune Sera; D013385:Succinate Dehydrogenase