title: FTIR studies of the redox partner interaction in cytochrome P450: the Pdx-P450cam couple.
abstract: Recently we have developed a new approach to study protein-protein interactions using Fourier transform infrared spectroscopy in combination with titration experiments and principal component analysis (FTIR-TPCA). In the present paper we review the FTIR-TPCA results obtained for the interaction between cytochrome P450 and the redox partner protein in two P450 systems, the Pseudomonas putida P450cam (CYP101) with putidaredoxin (P450cam-Pdx), and the Bacillus megaterium P450BM-3 (CYP102) heme domain with the FMN domain (P450BMP-FMND). Both P450 systems reveal similarities in the structural changes that occur upon redox partner complex formation. These involve an increase in beta-sheets and alpha-helix content, a decrease in the population of random coil/3(10)-helix structure, a redistribution of turn structures within the interacting proteins and changes in the protonation states or hydrogen-bonding of amino acid carboxylic side chains. We discuss in detail the P450cam-Pdx interaction in comparison with literature data and conclusions drawn from experiments obtained by other spectroscopic techniques. The results are also interpreted in the context of a 3D structural model of the Pdx-P450cam complex.
authors.affiliation: Max-Delbrück-Center for Molecular Medicine, Protein Dynamics Laboratory, Robert-Rössle Strasse 10, 13125 Berlin, Germany.
authors.forename: Andrey
authors.initials: A
authors.lastname: Karyakin
authors.forename: Domantas
authors.initials: D
authors.lastname: Motiejunas
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Wade
authors.forename: Christiane
authors.initials: C
authors.lastname: Jung
mesh_terms: D001410:Bacillus megaterium / Q000201:enzymology; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D019475:Camphor 5-Monooxygenase / Q000737:chemistry / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000378:metabolism*; D005288:Ferredoxins / Q000378:metabolism*; D006418:Heme / Q000378:metabolism; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D009251:NADPH-Ferrihemoprotein Reductase; D010084:Oxidation-Reduction; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016958:Pseudomonas putida / Q000201:enzymology; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001426:Bacterial Proteins; D005288:Ferredoxins; D006418:Heme; C100137:putidaredoxin; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D019475:Camphor 5-Monooxygenase; D009251:NADPH-Ferrihemoprotein Reductase; C052423:flavocytochrome P450 BM3 monoxygenases