Copper(II), Nickel(II) and Zinc(II) Complexes of Peptide Fragments of Tau Protein.
Molecules
; 29(10)2024 May 07.
Article
en En
| MEDLINE
| ID: mdl-38792033
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 the 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) ions, 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 relatively low thermodynamic stability with these peptides. The copper(II)-catalyzed oxidation of the peptides was also studied. In the presence of H2O2, the fragmentation of peptides was detected in all cases. In the simultaneous presence of H2O2 and ascorbic acid, the fragmentation of the peptide is less preferred, and the formation of 2-oxo-histidine also occurs.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Fragmentos de Péptidos
/
Zinc
/
Proteínas tau
/
Cobre
/
Complejos de Coordinación
/
Níquel
Idioma:
En
Revista:
Molecules
Asunto de la revista:
BIOLOGIA
Año:
2024
Tipo del documento:
Article
País de afiliación:
Hungria