Mixed metal copper(II)-nickel(II) and copper(II)-zinc(II) complexes of multihistidine peptide fragments of human prion protein

Binary and ternary mixed metal complexes of terminally free peptides containing two different histidyl binding sites

“…The results also proved that in the mixed metal species always copper(II) ions saturate the N-terminal sites and nickel (II) coordination is shifted to the internal histidyl residues. This conclusion is slightly different from those reported for the mixed metal copper(II)-nickel(II) species of the peptide fragments of prion protein [19]. In the latter system the addition of nickel(II) ions to the copper(II) [15,19].…”

“…The metal ion to ligand ratios were selected as 1:1 and 2:1 for binary systems and 1 and overall stability constants (log β pqrs ) of the metal complexes were calculated by means of the general computational programs, (PSEQUAD and SUPERQUAD) as described in our previous publications [19,20]. The equilibrium constants were defined by equations (1) and (2) for the binary and (3) and (4) for the ternary systems.…”

“…These observations promoted the launch of systematic studies on the mixed metal complexes of various multihistidine peptides. The preliminary studies in this field involved the complexes of simple multihistidine model peptides [17] and various fragments of prion protein [18,19] and amyloid-β peptide [20,21]. On the other hand, the comparison of the metal binding affinities of the different coordination modes created by histidyl residues is also crucial for the determination of the favoured coordination isomers.…”

Combined EXAFS and DFT Structure Calculations Provide Structural Insights into the 1:1 Multi‐Histidine Complexes of CuII, CuI, and ZnII with the Tandem Octarepeats of the Mammalian Prion Protein

“…The N‐terminal region of PrP has also been reported to bind other metals 22–25. Copper coordination to PrP has also been observed to be redox‐active, cycling between Cu II and Cu I 26.…”

Equilibrium Studies of Cobalt (II) and Copper (II) with Diethylene Triamine Penta Acetic Acid (DTPA)

“…Some publications on multiple equilibria and chemical distribution of biometals with some biologically potential ligands is worth mentioning [6,7]. Heterobinuclear complexes of transition metals have been investigated by Nair and his group [8].. Few interesting investigations on heterobimetallic complexes having Mixed-ligand, mixedmetal complexes involving more than one metal ions of the same or different types may prove as better models for multimetal multiligand equilibria occurring in the biological systems may be reported in 2014 [9][10].…”