Anisotropic covalency contributions to superexchange pathways in type one copper active sites.

ABSTRACT: Type one (T1) Cu sites deliver electrons to catalytic Cu active sites: the mononuclear type two (T2) Cu site in nitrite reductases (NiRs) and the trinuclear Cu cluster in the multicopper oxidases (MCOs). The T1 Cu and the remote catalytic sites are connected via a Cys-His intramolecular electron-transfer (ET) bridge, which contains two potential ET pathways: P1 through the protein backbone and P2 through the H-bond between the Cys and the His. The high covalency of the T1 Cu-S(Cys) bond is shown here to activate the T1 Cu site for hole superexchange via occupied valence orbitals of the bridge. This covalency-activated electronic coupling (H(DA)) facilitates long-range ET through both pathways. These pathways can be selectively activated depending on the geometric and electronic structure o

SUBMITTER: Hadt RG 

PROVIDER: S-EPMC4210080 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature