A model for cytochrome oxidase.

G Palmer; G T Babcock; L E Vickery

doi:10.1073/pnas.73.7.2206

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A model for cytochrome oxidase.

G Palmer·G T Babcock·L E Vickery

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Abstract

A model is proposed for the active center of cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase, EC 1.9.3.1) in which cytochrome a is a low-spin ferrihemoprotein and cytochrome a3 is a high-spin ferrihemoprotein antiferromagnetically coupled to one of the two Cu2+ ions present in the enzyme. It is further proposed that reduction is accompanied by a conformational change in the enzyme thus exposing the sixth coordination site of cytochrome a3 to ligands. With this model it is possible to account for a variety of outstanding observations including the results of magnetic circular dichroism, Mossbauer, and electron paramagnetic resonance spectroscopies, as well as magnetic susceptibility measurements.

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Binding Sites Circular Dichroism Copper Electron Spin Resonance Spectroscopy Electron Transport Complex IV Hemeproteins Ligands Magnetics Models, Structural Protein Conformation Journal Article Research Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

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G Palmer, G T Babcock, L E Vickery. 1976. A model for cytochrome oxidase.. https://doi.org/10.1073/pnas.73.7.2206

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