• Journal of Microbiology and Biotechnology
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• v.7 no.6
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• pp.378-385
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• 1997

Cation motive ATPases on cell membranes of Helicobacter pylori were investigated using everted membrane vesicles. Latent ATPases could be ascertained from aggregated vesicle using N, N-dimethylformamide (DMF) and Triton X-100. By contrast, ultrasonication or chloroform treatments caused membranes to be disrupted, resulting in an alteration of sensitivities against azide or vanadate. Considerable amounts of vanadate-sensitive enzymes were identified from vesicle micelles, prepared by the dilution method. These were activated in the presence of either $Ni^{2+}\;or\;NH_4^+$. From studies employing H. pylori intact cell systems, we found that ATPase expression of this bacterium was markedly dependent upon air composition. It was interesting that cellular expression of $Ni^{2+}$- or $NH_4^{+}$-motive ATPases was significantly affected by extracellular pH, suggesting that these unique enzymes may physiologically be involved in cellular $Ni^2$ import and $NH_4^+$ export, respectively.