title: The zinc-binding fragment of HypA from Helicobacter pylori: a tempting site also for nickel ions.
abstract: HypA, a nickel accessory protein from H. pylori, binds a zinc ion in it's structural site, a loop with two conserved CXXC motifs (Ac-ELECKDCSHVFKPNALDYGVCEKCHS-NH(2)). There are at least three hypotheses on the binding mode of this ion. In this paper, we try to understand how Zn(2+) binds to this fragment and why Ni(2+), a metal with quite a high affinity towards thiolic sites, doesn't compete with zinc in the binding to this motif. Potentiometric titrations, mass spectrometry, NMR, UV-Vis and CD spectroscopy help us to compare the coordination modes in both metal complexes and discuss their thermodynamic stabilities.
authors: Department of Chemistry, University of Wroclaw, F. Joliot-Curie 14, 50-383 Wroclaw, Poland.
authors: Magdalena
authors: M
authors: Rowinska-Zyrek
authors: Slawomir
authors: S
authors: Potocki
authors: Danuta
authors: D
authors: Witkowska
authors: Daniela
authors: D
authors: Valensin
authors: Henryk
authors: H
authors: Kozlowski
mesh_terms: D020816:Amino Acid Motifs; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002942:Circular Dichroism; D056831:Coordination Complexes / Q000737:chemistry / Q000378:metabolism; D016480:Helicobacter pylori / Q000378:metabolism*; D007477:Ions / Q000737:chemistry; D056511:Metallochaperones; D008969:Molecular Sequence Data; D009532:Nickel / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D016415:Sequence Alignment; D013816:Thermodynamics; D015032:Zinc / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D056831:Coordination Complexes; C578705:HypA protein, Helicobacter pylori; D007477:Ions; D056511:Metallochaperones; D009532:Nickel; D015032:Zinc