Coordination of Cu(2+)and Ni(2+) with the histone model peptide of H2B N-terminal tail (1-31 residues): A spectroscopic study

Dalton Trans. 2010 May 14;39(18):4369-81. doi: 10.1039/b927157k. Epub 2010 Mar 31.

Abstract

The interaction of Cu(2+) and Ni(2+) with the N-terminal tail of histone H2B, the 31 amino acid peptide H2B(1-31) (Ac-PEPAKSAPAPKKG(13)SKKAVTKAQKKD(25)GKKRKR-NH(2)), studied by various spectroscopic techniques (UV/Vis, CD, EPR and NMR) are described. The results showed the formation of Cu(2+)-H2B(1-31) complexes above pH 7.3 most probably through the beta-carboxylate group of D25. With the increase of the pH, a mixture of 3 N and 4 N species presenting {2N(-), CO, epsilonNH(2)} and {2N(-), OH(2), epsilonNH(2)}{epsilonNH(2)} coordination modes, respectively is formed, while at highly basic solutions the binding of an additional amide donor is suggested. NMR spectroscopy supported by CD spectroscopy indicated that Ni(2+) coordination takes place most likely through Q22-K23-K24-D25 peptide fragment. Direct coordination to Ni(2+), in a {4N(-)} coordination mode, with a severe conformation change in all residues from G13 to G26 was observed. Cu(2+) and Ni(2+) binding to the N-terminal tail of H2B causes a severe conformational change that might interfere with histone post-translational modifications, possibly leading to epigenetic changes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Circular Dichroism
  • Copper / chemistry*
  • Electron Spin Resonance Spectroscopy
  • Histones / chemistry*
  • Hydrogen-Ion Concentration
  • Molecular Sequence Data
  • Nickel / chemistry*
  • Nuclear Magnetic Resonance, Biomolecular
  • Protein Structure, Tertiary
  • Spectrophotometry, Ultraviolet

Substances

  • Histones
  • Copper
  • Nickel