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Delicate conformational balance of the redox enzyme cytochrome P450cam.

ABSTRACT: The energy landscapes of proteins are highly complex and can be influenced by changes in physical and chemical conditions under which the protein is studied. The redox enzyme cytochrome P450cam undergoes a multistep catalytic cycle wherein two electrons are transferred to the heme group and the enzyme visits several conformational states. Using paramagnetic NMR spectroscopy with a lanthanoid tag, we show that the enzyme bound to its redox partner, putidaredoxin, is in a closed state at ambient temperature in solution. This result contrasts with recent crystal structures of the complex, which suggest that the enzyme opens up when bound to its partner. The closed state supports a model of catalysis in which the substrate is locked in the active site pocket and the enzyme acts as an insulator for the reactive intermediates of the reaction.

SUBMITTER: Skinner SP

PROVIDER: S-EPMC4517283 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature

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Delicate conformational balance of the redox enzyme cytochrome P450cam.

Skinner Simon P SP Liu Wei-Min WM Hiruma Yoshitaka Y Timmer Monika M Blok Anneloes A Hass Mathias A S MA Ubbink Marcellus M

Proceedings of the National Academy of Sciences of the United States of America 20150630 29

The energy landscapes of proteins are highly complex and can be influenced by changes in physical and chemical conditions under which the protein is studied. The redox enzyme cytochrome P450cam undergoes a multistep catalytic cycle wherein two electrons are transferred to the heme group and the enzyme visits several conformational states. Using paramagnetic NMR spectroscopy with a lanthanoid tag, we show that the enzyme bound to its redox partner, putidaredoxin, is in a closed state at ambient t ...[more]

PMID: 26130807

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