DFT Fe_a3-O/O-O Vibrational Frequency Calculations over Catalytic Reaction Cycle States in the Dinuclear Center of Cytochrome c Oxidase.

ABSTRACT: Density functional vibrational frequency calculations have been performed on eight geometry optimized cytochrome c oxidase (CcO) dinuclear center (DNC) reaction cycle intermediates and on the oxymyoglobin (oxyMb) active site. The calculated Fe-O and O-O stretching modes and their frequency shifts along the reaction cycle have been compared with the available resonance Raman (rR) measurements. The calculations support the proposal that in state A[Fe_a3³⁺-O₂^-•···Cu_B⁺] of CcO, O₂ binds with Fe_a3²⁺ in a similar bent end-on geometry to that in oxyMb. The calculations show that the observed 20 cm^-1 shift of the Fe_a3-O stretching mode from the

SUBMITTER: Du WH 

PROVIDER: S-EPMC6839913 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature