Affinity, speciation, and molecular features of copper(II) complexes with a prion tetraoctarepeat domain in aqueous solution: insights into old and new results
Affinity, speciation, and molecular features of copper(II) complexes with a prion tetraoctarepeat domain in aqueous solution: insights into old and new results(586 views) Di Natale G, Osz K, Kállay C, Pappalardo G, Sanna D, Impellizzeri G, Sóvágó I, Rizzarelli E
Chemistry (ISSN: 1521-3765, 0947-6539, 1521-3765electronic), 2013 Mar 11; 19(11): 3751-3761.
Keywords: Copper Chemistry, Organometallic Compounds Chemical Synthesis Chemistry, Prions Chemical Synthesis Chemistry, Solutions, Spectrometry, Mass, Electrospray Ionization, Water Chemistry, Circular Dichroism, Coordination Modes, Peptides, Uv Vis Spectroscopy, Binding Modes, Copper Complexes, Metal-To-Ligand Ratio, Molecular Feature, New Results, Peptide Sequences, Ph Range, Potentiometric, Redox Activity, Binding Energy, Magnetic Resonance, Metal Complexes, Paramagnetism, Redox Reactions, Stoichiometry, Ultraviolet Visible Spectroscopy, Copper Compounds, Article, Electrospray Mass Spectrometry, Solution And Solubility,
Affiliations: *** IBB - CNR ***
CNR Institute of Biostructures and Bioimaging, V.le A. Doria 6, 95125 Catania, Italy.
Department of Physical Chemistry, University of Debrecen, 4010 Debrecen, Hungary
MTA-DE Research Group on Homogeneous Catalysis and Reaction Mechanisms, Debrecen, Hungary
Department of Chemical Sciences, University of Catania, V.le A. Doria 6, 95125 Catania, Italy
Department of Inorganic and Analytical Chemistry, University of Debrecen, 4010 Debrecen, Hungary
References: Not available.
Affinity, speciation, and molecular features of copper(II) complexes with a prion tetraoctarepeat domain in aqueous solution: insights into old and new results
Characterization of the copper(II) complexes formed with the tetraoctarepeat peptide at low and high metal-to-ligand ratios and in a large pH range, would provide a breakthrough in the interpretation of biological relevance of the different metal complexes of copper(II)-tetraoctarepeat system. In the present work, the potentiometric, UV/Vis, circular dichroism (CD), and electron paramagnetic resonance (EPR) studies were carried out on copper(II) complexes with a PEG-ylated derivative of the tetraoctarepeats peptide sequence (Ac-PEG27 -(PHGGGWGQ)4 -NH2 ) and the peptide Ac-(PHGGGWGQ)2 -NH2 . Conjugation of tetraoctarepeat peptide sequence with polyethyleneglycol improved the solubility of the copper(II) complexes. The results enable a straightforward explanation of the conflicting results originated from the underestimation of all metal-ligand equilibria and the ensuing speciation. A complete and reliable speciation is therefore obtained with the released affinity and binding details of the main complexes species formed in aqueous solution. The results contribute to clarify the discrepancies of several studies in which the authors ascribe the redox activity of copper(II)-tetraoctarepeat system considering only the average effects of several coexisting species with very different stoichiometries and binding modes. Copyright 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Affinity, speciation, and molecular features of copper(II) complexes with a prion tetraoctarepeat domain in aqueous solution: insights into old and new results
No results.
Affinity, speciation, and molecular features of copper(II) complexes with a prion tetraoctarepeat domain in aqueous solution: insights into old and new results