One of the research topics in our group is protein Cap 43, which seems directly related to the cellular response after nickel exposure, [1, 2] as well as to a number of cancers.[1, 3] The studies we carried out for several years started from a small peptide model of Cap 43 and were successively expanded to include a two- (TRSRSHTSEG-TRSRSHTSEG) and a three-repeated (TRSRSHTSEG-TRSRSHTSEG-TRSRSHTSEG) monohistidinic decapeptide fragment in its C-terminus.[4-6] Such 20- and 30-amino acid sequences were tested for Ni(II)- and Cu(II)- coordination at different pH values, by both potentiometry and spectroscopic techniques (NMR, EPR, UV-Vis, CD). The two metals showed a slightly different behaviour towards coordination, and the interaction of Cu(II) ions with the two peptides started at pH values lower than those for Ni(II). What appeared clear was that in both cases each 10-amino acid fragment TRSRSHTSEG was able to coordinate a single metal ion to form a square planar 4N {4N} chromophore. The coordination mode involved an imidazole nitrogen from the His residue, and the amidic nitrogens from His, Ser, and Arg. At high pH values, further deprotonations were observed for the Cu(II) species.
Interaction of protein Cap43 with Ni(II) and Cu(II) ions / Zoroddu, Maria Antonietta; Peana, Massimiliano Francesco; Medici, Serenella; Kowalik Jankowska, Teresa; Kozlowski, Henryk. - (2008), pp. 329-329. (Intervento presentato al convegno Eurobic9: 9° European biological inorganic chemistry conference tenutosi a Wroclaw, Polonia nel 2-6 Settembre 2008).
Interaction of protein Cap43 with Ni(II) and Cu(II) ions
ZORODDU, Maria Antonietta;PEANA, Massimiliano Francesco;MEDICI, Serenella;
2008-01-01
Abstract
One of the research topics in our group is protein Cap 43, which seems directly related to the cellular response after nickel exposure, [1, 2] as well as to a number of cancers.[1, 3] The studies we carried out for several years started from a small peptide model of Cap 43 and were successively expanded to include a two- (TRSRSHTSEG-TRSRSHTSEG) and a three-repeated (TRSRSHTSEG-TRSRSHTSEG-TRSRSHTSEG) monohistidinic decapeptide fragment in its C-terminus.[4-6] Such 20- and 30-amino acid sequences were tested for Ni(II)- and Cu(II)- coordination at different pH values, by both potentiometry and spectroscopic techniques (NMR, EPR, UV-Vis, CD). The two metals showed a slightly different behaviour towards coordination, and the interaction of Cu(II) ions with the two peptides started at pH values lower than those for Ni(II). What appeared clear was that in both cases each 10-amino acid fragment TRSRSHTSEG was able to coordinate a single metal ion to form a square planar 4N {4N} chromophore. The coordination mode involved an imidazole nitrogen from the His residue, and the amidic nitrogens from His, Ser, and Arg. At high pH values, further deprotonations were observed for the Cu(II) species.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.