Wydział Chemii

Maria Antonietta Zoroddu

Massimiliano Peana

Teresa Kowalik-Jankowska

Henryk Kozłowski

Max Costa

2004

Journal of Inorganic Biochemistry

98

931-939

10.1016/j.jinorgbio.2004.03.005

Naukowa

Angielski

Artykuł

Cap43 protein has been tested for metal binding domains. The protein, specifically induced by nickel compounds in cultured human cells, had a new mono-histidinic motif consisting of 10 amino acids repeated three times in the C-terminus.The 20-Ac-TRSRSHTSEG–TRSRSHTSEG (Thr³⁴¹–Arg–Ser–Arg–Ser–His³⁴⁶–Thr–Ser–Glu–Gly–Thr–Arg–Ser–Arg–Ser–His³⁵⁶–Thr–Ser–Glu–Gly³⁶⁰ – peptide 1) and the 30–Ac-TRSRSHTSEG–TRSRSHTSEG–TRSRSHTSEG (Thr³⁴¹–Arg–Ser–Arg–Ser–His³⁴⁶–Thr–Ser–Glu–Gly–Thr–Arg–Ser–Arg–Ser–His³⁵⁶–Thr–Ser–Glu–Gly–Thr–Arg–Ser–Arg–Ser–His³⁶⁶–Thr–Ser–Glu–Gly³⁷⁰ – peptide 2) amino acids sequence has been analyzed as a site for Ni(II) binding. A combined pH-metric and spectroscopic (UV–visible, CD, NMR) studies of Ni(II) binding to both fragments were performed. The 20-amino acid peptide can bind one and two metal ions while the 30-amino acid fragment one, two and three metal ions. At physiological pH, depending on the metal to ligand molar ratio, peptide 1 forms the Ni₂L species while peptide 2 the NiL, Ni₂L and Ni₃L complexes where each metal ion is coordinated to the imidazole nitrogen atom of the histidine residue of the 10-amino acid fragment. Octahedral complexes at pH 8–9 and planar 4N complexes with (N_Im, 3N⁻) bonding mode at pH above 9, are formed. This work supports the existence of an interesting binding site at the COOH-terminal domain of the Cap43 protein.

Stability constants, Spectroscopic study, Nickel(II) complexes, Cap43 fragments

https://doi.org/10.1016/j.jinorgbio.2004.03.005

http://www.elsevier.com