Lead(II) complexes of oligopeptides containing two cysteine residues
| Autor: | Györgyi Szunyog, Katalin Várnagy |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010405 organic chemistry
Chemistry Stereochemistry Ligand chemistry.chemical_element Metal Binding Site Zinc 010402 general chemistry 01 natural sciences Medicinal chemistry 0104 chemical sciences Inorganic Chemistry Metal Természettudományok visual_art Materials Chemistry visual_art.visual_art_medium Molecule Chelation Physical and Theoretical Chemistry Binding site Kémiai tudományok Cysteine |
| Zdroj: | Inorganica Chimica Acta. 472:157-164 |
| ISSN: | 0020-1693 |
| DOI: | 10.1016/j.ica.2017.07.067 |
| Popis: | The complex formation processes of three oligopeptides (CysSerSerAlaCysSer-NH2, CSSACS-NH2; AlaCysSerSerAlaCysSer-NH2, ACSSACS-NH2; SerSerCysSerSerAlaCysSer-NH2, SSCSSACS-NH2) were studied in the presence of toxic lead(II) ions and compared to those of toxic cadmium(II) and essential zinc(II) ions. The stoichiometry and stability constants of the metal complexes were determined by potentiometry, while their structures were supported by means of UV- and NMR-spectroscopy. For hexapeptide containing cysteine in N-terminal position the (NH2,S−) donor groups are the primary metal binding site forming 5-membered chelate ring, and the coordination of C-terminal thiolate group contributes the stability of mono(ligand) complex excluding the formation of bis(ligand) species. The (S−,S−) donor set is, however, the main binding site, if the –CSSAC– sequence is farther from N-terminal amino group in the molecules, and mono- and bis(ligand) complexes are formed. The metal binding affinity of all three ligands are higher for lead(II) ion than zinc(II) ion resulting good selectivity of ligands for lead(II) over zinc(II). |
| Databáze: | OpenAIRE |
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