title: 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.
authors.affiliation: Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Simon P
authors.initials: SP
authors.lastname: Skinner
authors.affiliation: Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Liu
authors.affiliation: Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Hiruma
authors.affiliation: Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Monika
authors.initials: M
authors.lastname: Timmer
authors.affiliation: Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Anneloes
authors.initials: A
authors.lastname: Blok
authors.affiliation: Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: Mathias A S
authors.initials: MA
authors.lastname: Hass
authors.affiliation: Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands m.ubbink@chem.leidenuniv.nl.
authors.forename: Marcellus
authors.initials: M
authors.lastname: Ubbink
mesh_terms: D002164:Camphor / Q000737:chemistry; D019475:Camphor 5-Monooxygenase / Q000737:chemistry*; D005288:Ferredoxins; D008958:Models, Molecular; D009587:Nitrogen Isotopes; D010084:Oxidation-Reduction; D011487:Protein Conformation; D066244:Proton Magnetic Resonance Spectroscopy; D016958:Pseudomonas putida / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D005288:Ferredoxins; D009587:Nitrogen Isotopes; C100137:putidaredoxin; D002164:Camphor; D019475:Camphor 5-Monooxygenase
keywords: crystallography; cytochrome; dynamics; enzyme; paramagnetic NMR