Abstract
The histidine-rich protein, Hpn, binds to essential metals Ni2+, Cu2+, Zn2+ and a therapeutic metal Bi3+ with the in vitro affinities in the order of Cu2+ > Ni2+ > Bi3+ > Zn2+. In contrast, the in vivo (in E. coli) protection by the protein is in the order of Ni2+ > Bi3+ > Cu2+ approximately Zn2+. The release of Ni2+ from the protein follows a two-step process consisting of a rapidly established equilibrium and subsequently a rate-determining step (dissociation of Hpn-Ni...EDTA to Ni-EDTA). Our work suggests the nickel storage and homeostasis in H. pylori as the primary role of Hpn.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Bacterial Proteins / chemistry*
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Bacterial Proteins / genetics
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Binding, Competitive
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Bismuth / chemistry
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Bismuth / pharmacology
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Copper Sulfate / chemistry
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Copper Sulfate / pharmacology
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Edetic Acid / chemistry
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Escherichia coli / drug effects
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Escherichia coli / genetics
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Escherichia coli / growth & development
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Hydrogen-Ion Concentration
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Kinetics
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Metals / chemistry*
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Metals / pharmacology
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Molecular Sequence Data
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Nickel / chemistry
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Nickel / pharmacology
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Protein Binding
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Proteins / chemistry*
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Proteins / genetics
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Ranitidine / analogs & derivatives
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Ranitidine / chemistry
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Ranitidine / pharmacology
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Thermodynamics
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Zinc Sulfate / chemistry
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Zinc Sulfate / pharmacology
Substances
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Bacterial Proteins
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Metals
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Proteins
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histidine-rich proteins
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nickel sulfate
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Zinc Sulfate
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ranitidine bismuth citrate
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Nickel
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Ranitidine
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Edetic Acid
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Copper Sulfate
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Bismuth