Acid survival of Helicobacter pylori: how does urease activity trigger cytoplasmic pH homeostasis?
Autor(en): | Stingl, K Altendorf, K Bakker, EP |
Stichwörter: | ACIDOPHILIC BACTERIA; Biochemistry & Molecular Biology; CATION; DIFFERENCE; ESCHERICHIA-COLI-CELLS; MEMBRANE; Microbiology; MOTIVE FORCE; PROTON ELECTROCHEMICAL GRADIENT; RESISTANCE; SEQUENCE; TRANSPORT | Erscheinungsdatum: | 2002 | Herausgeber: | ELSEVIER SCIENCE LONDON | Journal: | TRENDS IN MICROBIOLOGY | Volumen: | 10 | Ausgabe: | 2 | Startseite: | 70 | Seitenende: | 74 | Zusammenfassung: | Helicobacter pylori can survive for several hours at pH 1 in the presence of urea. Under these conditions, the organism maintains its cytoplasmic pH at a value close to neutral. The role of the cytoplasmically located urease enzyme in this process is a matter of debate. We propose that cytoplasmic ammonia generated by the action of urease is protonated by H+ ions leaking in from the acidic medium and that the NH4+ formed is extruded from the cytoplasm via an as-yet-unidentified transport system. This mechanism is compared with the general mechanism of cytoplasmic pH homeostasis in microorganisms. |
ISSN: | 0966842X | DOI: | 10.1016/S0966-842X(01)02287-9 |
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geprüft am 20.05.2024