Thermodynamic and Structural Characterization of the Copper(II) Complexes of Peptides Containing Both Histidyl and Aspartyl Residues. (6th December 2007)

• Record Type: Journal Article
• Authors: Kállay, Csilla; Nagy, Zoltán; Várnagy, Katalin; Malandrinos, Gerasimos; Hadjiliadis, Nick; Sóvágó, Imre
• Other Names: Stillman Martin Academic Editor.
• Is Part Of: Bioinorganic chemistry and applications. Volume 2007(2007)
• Publication Date: 2007-12-06
• Subjects: Bioinorganic chemistry -- Periodicals; Bioinorganic chemistry; Biochemistry; Inorganic Chemistry; Chemistry, Bioinorganic; Periodicals; 572.51
• DOI: 10.1155/2007/30394
• Languages: English
• ISSNs: 1565-3633

Abstract

Abstract : Terminally protected pentapeptides with 2 histidines (Ac-HHVGD-NH 2 and Ac-HVGDH-NH 2 ) and the terminally free peptides containing both internal aspartyl and C-terminal histidyl residues (FDAH and VIDAH) have been synthesized, and copper(II) complexes studied by potentiometric, UV-Vis, CD, and EPR spectroscopic techniques in solution. Both thermodynamic and spectroscopic data reveal that side chain donor atoms of aspartyl and histidyl residues have a significant contribution to the metal binding affinity of peptide molecules. In the case of terminally protected peptides, the role of the imidazole-N donor functions is reflected in the enhanced stability of the 3N and 4N coordinated copper(II) complexes. The amino and β -carboxylate groups of FDAH and VIDAH create a very effective metal binding site with the (NH 2, N −, β - COO − ) and (NH 2, N −, N −, β - COO − ) coordination modes including the N-termini, while the histidine sites are available for the formation of the (N im, N −, N − ) binding mode resulting in the preference of dinuclear complex formation.