Stray Cu(II) may cause oxidative damage when coordinated to the -TESHHK- sequence derived from the C-terminal tail of histone H2A
(EN)
Mylonas, M.
(EN)
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας
(EL)
Mylonas, M.
(EN)
CH3CO-Thr-Glu-Ser-His-His-Lys-NH2, a hexapeptide representing the 120-125 sequence of histone H2A, coordinates Cu(II) ions efficiently. Monomeric complexes are formed. In the major complex at physiological pH, CuH-1L, Cu(II) is coordinated equatorially through the imidazole nitrogen of the His-4 residue and the amide nitrogens of the Ser-3 and His-4 residues, and axially through the imidazole nitrogen of the His-5 residue. This complex reacts with H2O2 and the resulting reactive oxygen intermediate efficiently oxidizes 2 ' -deoxyguanosine. The underlying mechanism involves the formation of Cu(III) and a metal-bound hydroxyl radical species.
(EN)
