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Copper(II), nickel(II) and zinc(II) complexes of hexapeptides containing separate aspartyl and histidyl residues

  • Metaadatok
Tartalom: http://dx.doi.org/10.1016/j.ica.2014.11.012
Archívum: MTA Könyvtár
Gyűjtemény: Status = Published



Type = Article
Cím:
Copper(II), nickel(II) and zinc(II) complexes of hexapeptides containing separate aspartyl and histidyl residues
Létrehozó:
Raics, Mária
Sanna, Daniele
Sóvágó, Imre
Kállay, Csilla
Dátum:
2015
Téma:
QD01 Analytical chemistry / analitikai kémia
QD03 Inorganic chemistry / szervetlen kémia
QH3011 Biochemistry / biokémia
Tartalmi leírás:
Copper(II), nickel(II) and zinc(II) complexes of two N-terminally free and C-terminally blocked hexapeptides, NH2-ADAAAH-NH2 and NH2-AADAAH-NH2, containing separate aspartyl and histidyl residues have been studied by potentiometric, UV-Vis, CD and ESR spectroscopic methods. The amino termini were found as the primary anchoring sites of both ligands for the complexation with all three metal ions. The ?-carboxylate function of the second or third aspartyl residue enhances the thermodynamic stability of the copper(II) and nickel(II) complexes and shifts the deprotonation of the subsequent amide functions into a more alkaline pH range. In the case of NH2-AADAAH-NH2 the imidazole-N donor of the histidyl residue does not have a significant contribution to the overall stability of the mononuclear complexes. The side chain imidazole, however, can be an independent metal binding site resulting in the formation of dinuclear or even mixed metal complexes. The stabilizing role of the histidyl residue is much more pronounced in the complexes of the NH2-ADAAAH-NH2 peptide. In this case a tridentately (NH2,N-,?-COO-)-coordinated species is formed and its stability is significantly enhanced by the macrochelation of the side chain imidazole. The presence of two anchoring sites (terminal amino and side chain imidazole) in one molecule enhances the stability of the corresponding zinc(II) complexes, too, but the amide nitrogens are not involved in metal binding in this case.
Típus:
Article
PeerReviewed
Formátum:
text
Azonosító:
Raics, Mária and Sanna, Daniele and Sóvágó, Imre and Kállay, Csilla (2015) Copper(II), nickel(II) and zinc(II) complexes of hexapeptides containing separate aspartyl and histidyl residues. INORGANICA CHIMICA ACTA, 426. pp. 99-106. ISSN 0020-1693
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