Density functional theory studies of oxygen and carbonate binding to a dicopper patellamide complex

Reza Latifi, Mojtaba Bagherzadeh, Bruce F. Milne, Marcel Jaspars, Sam P. de Visser

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


In this work we present results of density functional theory (DFT) calculations on dicopper patellamides and their affinity for molecular oxygen and carbonate. Patellamides are cyclic octapeptides that are produced by a cyanobacterium, and may show promise as therapeutics. Thus, carbonate binding to a dicopper patellamide center gives a stable cyclic octapeptide with a twist of almost 90°. The system exists in close-lying open-shell singlet and triplet spin states with two unpaired electrons in orthogonal σ∗ orbitals on each metal center. Subsequently, we replaced carbonate with dioxygen and found a stable Cu2(μ-O)2 diamond shaped patellamide core. In this structure the original dioxygen bond is significantly weakened to essentially a single bond, which should enable the system to transfer these oxygen atoms to substrates. We predicted the IR and Raman spectra of the Cu2(μ-O)2 diamond shaped patellamide structure using density functional theory and found a considerable isotope effect on the O–O stretch vibration for 16O2 versus 18O2 bound structures. Our studies reveal that carbonate forms an extremely stable complex with dicopper patellamide, but that additional molecular oxygen to this system does not give a potential oxidant. Therefore, it is more likely that carbonate prepares the system for dioxygen binding by folding it into the correct configuration followed in the proposed catalytic cycle by a protonation event preceding dioxygen binding to enable the system to reorganize to form a stable Cu2(μ-O)2-patellamide cluster. Alternatively, carbonate may act as an inhibitor that blocks the catalytic activity of the system. It is anticipated that the Cu2(μ-O)2-patellamide structure is a potential active oxidant of the dicopper patellamide complex.
Original languageEnglish
Pages (from-to)2171-2178
Number of pages8
JournalJournal of Inorganic Biochemistry
Issue number12
Early online date2 Sept 2008
Publication statusPublished - Dec 2008


  • density functional theory
  • carbonate
  • oxygen
  • copper
  • tyrosinase
  • ascidian lissoclinum-patella
  • C-H hydroxylation
  • taurine/alpha-ketoglutarate dioxygenase
  • mononuclear nonheme iron(IV)-OXO
  • copper proteins
  • ribonucleotide reductase
  • cyclic octapeptide
  • crystal-structure
  • diiron proteins
  • reactivity


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