Cu(II) and Ni(II) interactions with the terminally blocked hexapeptide Ac-Leu-Ala-His-Tyr-Asn-Lys-amide model of histone H2B (80-85) (EN)

Panagiotou, K. (EN)

Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας (EL)

Panagiotou, K. (EN)

The N- and C-terminal blocked hexapeptide Ac-Leu-Ala-His-Tyr-Asn-Lys-amide (LAHYNK) representing the 80-85 fragment of histone H2B was synthesized and its interactions with Cu(II) and Ni(II) ions were studied by potentiometric, UV-Vis, CD, EPR, and NMR spectroscopic techniques in solution. Our data reveal that the imidazole N(3) nitrogen atom is the primary ligating group for both metal ions. Sequential amide groups deprotonation and subsequent coordination to metal ions indicated an {N(imidazole), 3N(amide)} coordination mode above pH similar to 9, in all cases. In the case of Cu(II)-peptide system, the almost exclusive formation of the predominant species CuL in neutral media accounting for almost 98% of the total metal ion concentration at pH 7.3 strongly indicates that at physiological pH values the sequence -LAHYNK- of histone H2B provides very efficient binding sites for metal ions. The imidazole pyrrole N(1) ionization (but not coordination) was also detected in species CuH-4L present in solution above pH similar to 11. Copyright (C) 2008 Katerina Panagiotou et al. (EN)

metal-binding sequence (EN)

Πανεπιστήμιο Ιωαννίνων

Ιδρυματικό Αποθετήριο Ολυμπιάς

Σχολή Θετικών Επιστημών

Άρθρα σε επιστημονικά περιοδικά ( Ανοικτά)

ΑΠΟΘΕΤΗΡΙΟ "ΟΛΥΜΠΙΑΣ"

Τμήμα Χημείας

Bioinorg Chem Appl (EN)

Αγγλική γλώσσα

2008

http://olympias.lib.uoi.gr/jspui/handle/123456789/10262

<Go to ISI>://000255639900001

Hindawi Publishing Corporation (EN)