Copper-peptide complex structure and reactivity when found in conserved His-Xaa-His sequences

Ga Young Park, Jung Yoon Lee, Richard A. Himes, Gnana S. Thomas, Ninian Blackburn, Kenneth D. Karlin

Research output: Contribution to journalArticle

13 Scopus citations

Abstract

Oxygen-activating copper proteins may possess His-Xaa-His chelating sequences at their active sites and additionally exhibit imidiazole group δN vs εN tautomeric preferences. As shown here, such variations strongly affect copper ions coordination geometry, redox behavior, and oxidative reactivity. Copper(I) complexes bound to either δ-HGH or ε-HGH tripeptides were synthesized and characterized. Structural investigations using X-ray absorption spectroscopy, density functional theory calculations, and solution conductivity measurements reveal that δ-HGH forms the CuI dimer complex [{CuI(δ-HGH)}2]2+ (1) while ε-HGH binds CuI to give the monomeric complex [CuI(ε-HGH)]+ (2). Only 2 exhibits any reactivity, forming a strong CO adduct, [CuI(ε-HGH)(CO)]+, with properties closely matching those of the copper monooxygenase PHM. Also, 2 is reactive toward O2 or H2O2, giving a new type of O2-adduct or CuII-OOH complex, respectively.

Original languageEnglish (US)
Pages (from-to)12532-12535
Number of pages4
JournalJournal of the American Chemical Society
Volume136
Issue number36
DOIs
Publication statusPublished - Sep 10 2014

    Fingerprint

ASJC Scopus subject areas

  • Chemistry(all)
  • Catalysis
  • Biochemistry
  • Colloid and Surface Chemistry
  • Medicine(all)

Cite this