Isolation and characterization of a conserved porin protein from Helicobacter pylori
| Autor: | Trevor J. Trust, R. E. W. Hancock, P Doig, M. M. Exner |
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| Rok vydání: | 1995 |
| Předmět: |
Sequence analysis
Lipid Bilayers Molecular Sequence Data Porins Succinimides medicine.disease_cause Microbiology Membrane Potentials Haemophilus influenzae medicine Humans Amino Acid Sequence Molecular Biology Peptide sequence Helicobacter pylori Sequence Homology Amino Acid biology Molecular mass Electric Conductivity Antibodies Monoclonal biology.organism_classification Antibodies Bacterial Peptide Fragments Molecular Weight Cross-Linking Reagents Porin biology.protein Antibody Bacterial outer membrane Sequence Analysis Research Article |
| Zdroj: | Journal of Bacteriology. 177:5447-5452 |
| ISSN: | 1098-5530 0021-9193 |
| DOI: | 10.1128/jb.177.19.5447-5452.1995 |
| Popis: | Helicobacter pylori is a causative agent of gastritis in humans and is correlated with gastric ulcer formation. Infections with this bacterium have proven difficult to treat with antimicrobial agents. To better understand how this bacterium transports compounds such as antimicrobial agents across its outer membrane, identification of porin proteins is important. We have recently identified a family of H. pylori porins (HopA to HopD) (M. M. Exner, P. Doig, T. J. Trust, and R. E. W. Hancock, Infect. Immun. 63:1567-1572, 1995). Here, we report on an unrelated porin species (HopE) from this bacterium. This protein had a apparent molecular mass of 31 kDa and was seen to form 50- and 90-kDa aggregates that were designated putative dimeric and trimeric forms, respectively. The protein was purified to homogeneity and, with a model planar lipid membrane system, was shown to act as a nonselective pore with a single channel conductance in 1.0 M KCl of 1.5 nS, similarly to other bacterial nonspecific porins. An internal peptide sequence of HopE shared homology with the P2 porin of Haemophilus influenzae. HopE was also shown to be antigenic in vivo as assessed by sera taken from H. pylori-infected individuals and was immunologically conserved with both patient sera and specific monoclonal antibodies. From these data, it appears that HopE is a major nonselective porin of H. pylori. The implications of these findings are discussed. |
| Databáze: | OpenAIRE |
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