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Structure and quantum chemical characterization of chloroperoxidase compound 0, a common reaction intermediate of diverse heme enzymes.

ABSTRACT: We have determined the crystal structure of the chloroperoxidase (CPO) hydroperoxo reaction intermediate (CPO compound 0) at 1.75-A resolution. The intermediate was generated through controlled photoreduction of the CPO oxygen complex during x-ray data collection, which was monitored by recording of the crystal absorption spectra. Initially, the peroxo-anion species was formed and then protonated to yield compound 0. Quantum chemical calculations indicate that the peroxo-anion species is not stable and collapses instantaneously to compound 0. Compound 0 is present in the ferric low-spin doublet ground state and is characterized by a long O O bond length of 1.5 A and a Fe O bond distance of 1.8 A, which is also observed in the crystal structure.

SUBMITTER: Kuhnel K

PROVIDER: S-EPMC1765485 | biostudies-literature | 2007 Jan

REPOSITORIES: biostudies-literature

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Structure and quantum chemical characterization of chloroperoxidase compound 0, a common reaction intermediate of diverse heme enzymes.

Kühnel Karin K Derat Etienne E Terner James J Shaik Sason S Schlichting Ilme I

Proceedings of the National Academy of Sciences of the United States of America 20061226 1

We have determined the crystal structure of the chloroperoxidase (CPO) hydroperoxo reaction intermediate (CPO compound 0) at 1.75-A resolution. The intermediate was generated through controlled photoreduction of the CPO oxygen complex during x-ray data collection, which was monitored by recording of the crystal absorption spectra. Initially, the peroxo-anion species was formed and then protonated to yield compound 0. Quantum chemical calculations indicate that the peroxo-anion species is not sta ...[more]

PMID: 17190816

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