Zinc(ii) binding ability of tri-, tetra- and penta-peptides containing two or three histidyl residues

Csilla Kállay, Katalin Sz, Adrienn Dávid, Zita Valastyán, Gerasimos Malandrinos, Nick Hadjiliadis, Imre Sóvágó

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

Macroscopic and microscopic protonation processes and zinc(ii) complexes of a series of multihistidine peptides (Ac-HGH-OH, Ac-HGH-NHMe, Ac-HHGH-OH, Ac-HHGH-NHMe, Ac-HVGDH-NH2, Ac-HHVGD-NH2, Ac-HVHAH-NH 2, Ac-HAHVH-NH2, Ac-HPHAH-NH2 and Ac-HAHPH-NH2) were studied by potentiometric, NMR and ESI-MS spectroscopic techniques. Protonations of histidyl imidazole-N donor functions were not much affected by the number and location of histidyl residues, but the presence of C-terminal carboxylate groups had a significant impact on the basicities of the neighbouring histidyl sites. The formation of 2Nim and 3Nim macrochelates with the stoichiometry of [ZnL] was the major process in the complexation reactions of all peptides followed by the formation of hydroxo or amide bonded species. Thermodynamic stabilities of the zinc(ii) complexes were primarily determined by the number of histidyl residues, but the presence of C-terminal carboxylate functions has also a significant contribution to metal binding. The stabilizing effect of the aspartyl β-carboxylate group was also observed, but its extent is much weaker than that of the C-terminal carboxylate with a neighbouring histidyl residue. Zinc(ii) promoted peptide amide deprotonation and co-ordination was observed only in the zinc(ii)-Ac-HHVGD-NH2 system above pH 8.

Original languageEnglish
Pages (from-to)4040-4047
Number of pages8
JournalDalton Transactions
Issue number36
DOIs
Publication statusPublished - Sep 14 2007

    Fingerprint

ASJC Scopus subject areas

  • Inorganic Chemistry

Cite this