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001-es BibID:	BIBFORM117863
035-os BibID:	(WOS)001137891900001 (Scopus)85181518337
Első szerző:	Bonczidai-Kelemen Dóra
Cím:	The role of the terminal cysteine moiety in a metallopeptide mimicking the active site of the NiSOD enzyme / Dóra Bonczidai-Kelemen, Klaudia Tóth, István Fábián, Norbert Lihi
Dátum:	2024
ISSN:	1477-9226
Megjegyzések:	Superoxide dismutase (SOD) enzymes are pivotal in regulating oxidative stress. In order to model Ni containing SOD enzymes, the results of the thermodynamic, spectroscopic and SOD activity studies on the complexes formed between nickel(ii) and a NiSOD related peptide, CysCysAspLeuProCysGlyValTyr-NH2 (wtCC), are reported. Cysteine was introduced to replace the first histidine residue in the amino acid sequence of the active site of the NiSOD enzyme. The novel peptide exhibits 3 times higher metal binding affinity compared to the native NiSOD fragment. This is due to the presence of the first cysteine in the coordination sphere of nickel(ii). At physiological pH, the (NH2,S-,S-,S-) coordinated complex is the major species. This coordination mode is altered when one thiolate group is replaced by an amide nitrogen of the peptide backbone above pH 7.5. The nickel complexes of wtCC exhibit similar SOD activity to that of the complex formed with the active site fragment of the native NiSOD. The reaction between the complexes and the superoxide anion was studied by the sequential stopped-flow method. These studies revealed that the nickel(ii) complex is always in excess over the nickel(iii) complex during the dismutation process. However, the nickel(iii) species is also involved in a relatively fast degradation process. This unambiguously proves that a protective mechanism must be operative in the NiSOD enzyme which prevents the oxidation of the sulfur atom of cysteine in the presence of O2?. The results provide new possibilities for the use of NiSOD mimics in bio- and industrial catalytic processes.
Tárgyszavak:	Természettudományok Kémiai tudományok magyar nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Amino acids Binding energy Coordination reactions Nickel compounds Peptides pH Superoxide dismutase Active site Amino acid sequence Histidine residues Metallopeptides Ni-containing superoxide dismutase Nickel complex Super oxide dismutase Superoxide dismutase activities Superoxide dismutases Terminal cysteine Amides
Megjelenés:	Dalton Transactions. - 53 : 4 (2024), p. 1648-1656. -
További szerzők:	Tóth Klaudia Fábián István (1956-) (vegyész) Lihi Norbert (1990-) (vegyész)
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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