Version 1
: Received: 25 March 2024 / Approved: 26 March 2024 / Online: 26 March 2024 (14:29:44 CET)
How to cite:
Kastal, Z.; Balabán, A.; Vida, S.; Kallay, C.; Nagy, L.; Várnagy, K.; Sóvágó, I. Copper(II), Nickel(II) and Zinc(II) Complexes of Peptide Fragments of Tau Protein. Preprints2024, 2024031591. https://doi.org/10.20944/preprints202403.1591.v1
Kastal, Z.; Balabán, A.; Vida, S.; Kallay, C.; Nagy, L.; Várnagy, K.; Sóvágó, I. Copper(II), Nickel(II) and Zinc(II) Complexes of Peptide Fragments of Tau Protein. Preprints 2024, 2024031591. https://doi.org/10.20944/preprints202403.1591.v1
Kastal, Z.; Balabán, A.; Vida, S.; Kallay, C.; Nagy, L.; Várnagy, K.; Sóvágó, I. Copper(II), Nickel(II) and Zinc(II) Complexes of Peptide Fragments of Tau Protein. Preprints2024, 2024031591. https://doi.org/10.20944/preprints202403.1591.v1
APA Style
Kastal, Z., Balabán, A., Vida, S., Kallay, C., Nagy, L., Várnagy, K., & Sóvágó, I. (2024). Copper(II), Nickel(II) and Zinc(II) Complexes of Peptide Fragments of Tau Protein. Preprints. https://doi.org/10.20944/preprints202403.1591.v1
Chicago/Turabian Style
Kastal, Z., Katalin Várnagy and Imre Sóvágó. 2024 "Copper(II), Nickel(II) and Zinc(II) Complexes of Peptide Fragments of Tau Protein" Preprints. https://doi.org/10.20944/preprints202403.1591.v1
Abstract
Copper(II), nickel(II) and zinc(II) complexes of various peptide fragments of tau protein were studied by potentiometric and spectroscopic techniques. All peptides contained one histidyl residue and represented the sequences of tau(91-97) (Ac-AQPHTEI-NH2), tau(385-390) (Ac-KTDHGA-NH2) and tau(404-409) (Ac-SPRHLS-NH2). Imidazole-N donors of histidine were the primary metal binding sites for all peptides and all metal ions but in case of copper(II) and nickel(II) the deprotonated amide groups were also involved in metal binding by increasing pH. The most stable complexes were formed with copper(II) ion but the presence of prolyl residues resulted in significant changes in the thermodynamic stability and speciation of the systems. It was also demonstrated that nickel(II) and especially zinc(II) complexes have relative low thermodynamic stability with these peptides. Copper(II) catalyzed oxidation of the peptides was also studied. In the presence of H2O2 the fragmentation of peptides can be detected in all cases. In the simultaneous presence of of H2O2 and ascorbic acid the extent of the fragmentation of the peptide is less preferred, and the formation of 2-oxo-histidine also occurs.
Keywords
tau protein; histidine containing fragments; copper(II) complex; zinc(II) complex; nickel(II) complex; copper(II) catalysed oxidation; potentiometry; UV-Vis spectroscopy; CD spectroscopy
Subject
Chemistry and Materials Science, Other
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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