How the α-hydroxymethylserine residue stabilizes oligopeptide complexes with nickel(II) and copper(II) ions
- 13 March 2000
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in J. Chem. Soc., Dalton Trans.
- No. 7,p. 1033-1038
- https://doi.org/10.1039/a909354k
Abstract
Potentiometric, spectroscopic and theoretical studies have shown that the α-hydroxymethylserine (HmS) residue is a very specific amino acid residue when inserted into a peptide sequence. The theoretical calculations as well as evaluated deprotonation microconstants indicated that in the HmS-HmS-His tripeptide the N-terminal ammonium group is more acidic than the imidazole nitrogen. The hydrogen bond formation between the N-terminal amino group and imidazole nitrogen stabilizes the cyclic conformation of the metal-free peptide. The unusual gain in the 4N complex stability in the copper(II) and nickel(II) complexes with HmS-HmS-His ligands seems to derive from the enhancement of the π-electron contribution to the metal–amide nitrogen bond.Keywords
This publication has 0 references indexed in Scilit: