P450 versus P420: correlation between cyclic voltammetry and visible absorption spectroscopy of the immobilized heme domain of cytochrome P450 BM3. 2008

Paola Panicco, and Yeni Astuti, and Andrea Fantuzzi, and James R Durrant, and Gianfranco Gilardi
Division of Molecular Biosciences and Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, UK.

Cyclic voltabsorptometry is used for the first time to distinguish and characterize electrochemically the active (P450) and inactive (P420) forms of cytochromes P450 immobilized on an electrode during voltammetry experiments. This was achieved by using the heme domain (BMP) of the bacterial cytochrome P450 BM3 from Bacillus megaterium (CYP102A1) immobilized on mesopouros tin-oxide (SnO2) electrodes. We demonstrate that the formation of either the P450 form or the P420 one can be obtained by modifying the mesoporous electrode surface with polycations with different properties such as polyethylenimmine (PEI) and polydiallyldimethylammonium chloride (PDDA). Potential step spectroelectrochemistry allowed measurement of reduction potentials of the active P450 form. Values of -0.39+/-0.01 V and -0.58+/-0.01 V (both versus Ag/AgCl) were calculated for the active P450 form immobilized on the BMP/PDDA-SnO2 and BMP/PEI-SnO2 electrodes, respectively. The cyclic voltabsorptometric experiments showed how, when both the active and inactive forms are present on the PEI film, the inactive P420 species tends to dominate the cyclic voltammetric signal.

UI MeSH Term Description Entries
D007097 Imines Organic compounds containing a carbon-nitrogen double bond where a NITROGEN atom can be attached to HYDROGEN or an alkyl or aryl group. Imine
D010100 Oxygen An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration. Dioxygen,Oxygen-16,Oxygen 16
D011095 Polyethylenes Synthetic thermoplastics that are tough, flexible, inert, and resistant to chemicals and electrical current. They are often used as biocompatible materials for prostheses and implants. Ethylene Polymers,Ethene Homopolymers,Homopolymers, Ethene,Polymers, Ethylene
D003577 Cytochrome P-450 Enzyme System A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism. Cytochrome P-450,Cytochrome P-450 Enzyme,Cytochrome P-450-Dependent Monooxygenase,P-450 Enzyme,P450 Enzyme,CYP450 Family,CYP450 Superfamily,Cytochrome P-450 Enzymes,Cytochrome P-450 Families,Cytochrome P-450 Monooxygenase,Cytochrome P-450 Oxygenase,Cytochrome P-450 Superfamily,Cytochrome P450,Cytochrome P450 Superfamily,Cytochrome p450 Families,P-450 Enzymes,P450 Enzymes,Cytochrome P 450,Cytochrome P 450 Dependent Monooxygenase,Cytochrome P 450 Enzyme,Cytochrome P 450 Enzyme System,Cytochrome P 450 Enzymes,Cytochrome P 450 Families,Cytochrome P 450 Monooxygenase,Cytochrome P 450 Oxygenase,Cytochrome P 450 Superfamily,Enzyme, Cytochrome P-450,Enzyme, P-450,Enzyme, P450,Enzymes, Cytochrome P-450,Enzymes, P-450,Enzymes, P450,Monooxygenase, Cytochrome P-450,Monooxygenase, Cytochrome P-450-Dependent,P 450 Enzyme,P 450 Enzymes,P-450 Enzyme, Cytochrome,P-450 Enzymes, Cytochrome,Superfamily, CYP450,Superfamily, Cytochrome P-450,Superfamily, Cytochrome P450
D003580 Cytochromes Hemeproteins whose characteristic mode of action involves transfer of reducing equivalents which are associated with a reversible change in oxidation state of the prosthetic group. Formally, this redox change involves a single-electron, reversible equilibrium between the Fe(II) and Fe(III) states of the central iron atom (From Enzyme Nomenclature, 1992, p539). The various cytochrome subclasses are organized by the type of HEME and by the wavelength range of their reduced alpha-absorption bands. Cytochrome
D004563 Electrochemistry The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes. Electrochemistries
D004566 Electrodes Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum. Anode,Anode Materials,Cathode,Cathode Materials,Anode Material,Anodes,Cathode Material,Cathodes,Electrode,Material, Anode,Material, Cathode
D006418 Heme The color-furnishing portion of hemoglobin. It is found free in tissues and as the prosthetic group in many hemeproteins. Ferroprotoporphyrin,Protoheme,Haem,Heme b,Protoheme IX
D000644 Quaternary Ammonium Compounds Derivatives of ammonium compounds, NH4+ Y-, in which all four of the hydrogens bonded to nitrogen have been replaced with hydrocarbyl groups. These are distinguished from IMINES which are RN Quaternary Ammonium Compound,Ammonium Compound, Quaternary,Ammonium Compounds, Quaternary,Compound, Quaternary Ammonium
D001410 Bacillus megaterium A species of bacteria whose spores vary from round to elongate. It is a common soil saprophyte. Bacillus megatherium

Related Publications

Paola Panicco, and Yeni Astuti, and Andrea Fantuzzi, and James R Durrant, and Gianfranco Gilardi
September 2004, Journal of inorganic biochemistry,
Paola Panicco, and Yeni Astuti, and Andrea Fantuzzi, and James R Durrant, and Gianfranco Gilardi
August 2004, Journal of the American Chemical Society,
Paola Panicco, and Yeni Astuti, and Andrea Fantuzzi, and James R Durrant, and Gianfranco Gilardi
June 2005, Inorganic chemistry,
Paola Panicco, and Yeni Astuti, and Andrea Fantuzzi, and James R Durrant, and Gianfranco Gilardi
July 2005, Archives of biochemistry and biophysics,
Paola Panicco, and Yeni Astuti, and Andrea Fantuzzi, and James R Durrant, and Gianfranco Gilardi
April 2018, Colloids and surfaces. B, Biointerfaces,
Paola Panicco, and Yeni Astuti, and Andrea Fantuzzi, and James R Durrant, and Gianfranco Gilardi
August 2006, Journal of the American Chemical Society,
Paola Panicco, and Yeni Astuti, and Andrea Fantuzzi, and James R Durrant, and Gianfranco Gilardi
November 2010, Proceedings of the National Academy of Sciences of the United States of America,
Paola Panicco, and Yeni Astuti, and Andrea Fantuzzi, and James R Durrant, and Gianfranco Gilardi
June 2022, ACS omega,
Paola Panicco, and Yeni Astuti, and Andrea Fantuzzi, and James R Durrant, and Gianfranco Gilardi
February 2004, Biochemistry,
Paola Panicco, and Yeni Astuti, and Andrea Fantuzzi, and James R Durrant, and Gianfranco Gilardi
November 1993, Biochemical Society transactions,
Copied contents to your clipboard!