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Fujiyama K, Hino T, Nagano S. Diverse reactions catalyzed by cytochrome P450 and biosynthesis of steroid hormone. Biophys Physicobiol 2022; 19:e190021. [PMID: 35859988 PMCID: PMC9260165 DOI: 10.2142/biophysico.bppb-v19.0021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 05/30/2022] [Indexed: 12/01/2022] Open
Abstract
Steroid hormones modulate numerous physiological processes in various higher organisms. Research on the physiology, biosynthesis, and metabolic degradation of steroid hormones is crucial for developing drugs, agrochemicals, and anthelmintics. Most steroid hormone biosynthetic pathways, excluding those in insects, have been elucidated, and the roles of several cytochrome P450s (CYPs, P450s), heme (iron protoporphyrin IX)-containing monooxygenases, have been identified. Specifically, P450s of the animal steroid hormone biosynthetic pathways and their three dimensional structures and reaction mechanisms have been extensively studied; however, the mechanisms of several uncommon P450 reactions involved in animal steroid hormone biosynthesis and structures and reaction mechanisms of various P450s involved in plant and insect steroid hormone biosynthesis remain unclear. Recently, we determined the crystal structure of P450 responsible for the first and rate-determining step in brassinosteroids biosynthesis and clarified the regio- and stereo-selectivity in the hydroxylation reaction mechanism. In this review, we have outlined the general catalytic cycle, reaction mechanism, and structure of P450s. Additionally, we have described the recent advances in research on the reaction mechanisms of steroid hormone biosynthesis-related P450s, some of which catalyze unusual P450 reactions including C–C bond cleavage reactions by utilizing either a heme–peroxo anion species or compound I as an active oxidizing species. This review article is an extended version of the Japanese article, Structure and mechanism of cytochrome P450s involved in steroid hormone biosynthesis, published in SEIBUTSU BUTSURI Vol. 61, p. 189–191 (2021).
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Affiliation(s)
- Keisuke Fujiyama
- Dormancy and Adaptation Research Unit, RIKEN Center for Sustainable Resource Science
| | - Tomoya Hino
- Center for Research on Green Sustainable Chemistry, Tottori University
| | - Shingo Nagano
- Center for Research on Green Sustainable Chemistry, Tottori University
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2
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Liu Y, Denisov IG, Grinkova YV, Sligar SG, Kincaid JR. P450 CYP17A1 Variant with a Disordered Proton Shuttle Assembly Retains Peroxo‐Mediated Lyase Efficiency. Chemistry 2020; 26:16846-16852. [DOI: 10.1002/chem.202003181] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Indexed: 11/07/2022]
Affiliation(s)
- Yilin Liu
- Department of Chemistry Marquette University 1414W Clybourn Street Milwaukee WI 53233 USA
| | - Ilia G. Denisov
- Departments of Biochemistry and Chemistry University of Illinois 116 Morrill Hall 505 S. Goodwin Avenue Urbana IL 61801 USA
| | - Yelena V. Grinkova
- Departments of Biochemistry and Chemistry University of Illinois 116 Morrill Hall 505 S. Goodwin Avenue Urbana IL 61801 USA
| | - Stephen G. Sligar
- Departments of Biochemistry and Chemistry University of Illinois 116 Morrill Hall 505 S. Goodwin Avenue Urbana IL 61801 USA
| | - James R. Kincaid
- Department of Chemistry Marquette University 1414W Clybourn Street Milwaukee WI 53233 USA
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3
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Soldatova AV, Spiro TG. Alternative modes of O 2 activation in P450 and NOS enzymes are clarified by DFT modeling and resonance Raman spectroscopy. J Inorg Biochem 2020; 207:111054. [PMID: 32217351 PMCID: PMC7247924 DOI: 10.1016/j.jinorgbio.2020.111054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/24/2020] [Accepted: 03/02/2020] [Indexed: 12/11/2022]
Abstract
The functions of heme proteins are modulated by hydrogen bonds (H-bonds) directed at the heme-bound ligands by protein residues. When the gaseous ligands CO, NO, or O2 are bound, their activity is strongly influenced by H-bonds to their atoms. These H-bonds produce characteristic changes in the vibrational frequencies of the heme adduct, which can be monitored by resonance Raman spectroscopy and interpreted with density functional theory (DFT) computations. When the protein employs a cysteinate proximal ligand, bound O2 becomes particularly reactive, the course of the reaction being controlled by H-bonding and proton delivery. In this work, DFT modeling is used to examine the effects of H-bonding to either the terminal (Ot) or proximate (Op) atom of methylthiolate-Fe(II)porphine-O2, as well as to the thiolate S atom. H-bonds to Op produce a positive linear correlation between ν(Fe - O) and ν(O - O), because they increase the sp2 character of Op, weakening both the Fe - O and O - O bonds. H-bonds to Ot produce a negative correlation, because they increase Fe backbonding, strengthening the Fe - O but weakening the O - O bond. Available experimental data accommodate well to the computed pattern. In particular, this correspondence supports the interpretation of cytochrome P450 data by Kincaid and Sligar [M. Gregory, P.J. Mak, S.G. Sligar, J.R. Kincaid, Angew. Chem. Int. Ed. 125 (2013) 5450-5453], involving steering between hydroxylation and lyase reaction channels by differential H-bonds. Similar channeling between the first and second steps of the nitric oxide synthase reaction is likely.
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Affiliation(s)
- Alexandra V Soldatova
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195, United States
| | - Thomas G Spiro
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195, United States.
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4
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Mak PJ, Denisov IG. Spectroscopic studies of the cytochrome P450 reaction mechanisms. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2018; 1866:178-204. [PMID: 28668640 PMCID: PMC5709052 DOI: 10.1016/j.bbapap.2017.06.021] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 06/22/2017] [Indexed: 10/19/2022]
Abstract
The cytochrome P450 monooxygenases (P450s) are thiolate heme proteins that can, often under physiological conditions, catalyze many distinct oxidative transformations on a wide variety of molecules, including relatively simple alkanes or fatty acids, as well as more complex compounds such as steroids and exogenous pollutants. They perform such impressive chemistry utilizing a sophisticated catalytic cycle that involves a series of consecutive chemical transformations of heme prosthetic group. Each of these steps provides a unique spectral signature that reflects changes in oxidation or spin states, deformation of the porphyrin ring or alteration of dioxygen moieties. For a long time, the focus of cytochrome P450 research was to understand the underlying reaction mechanism of each enzymatic step, with the biggest challenge being identification and characterization of the powerful oxidizing intermediates. Spectroscopic methods, such as electronic absorption (UV-Vis), electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), electron nuclear double resonance (ENDOR), Mössbauer, X-ray absorption (XAS), and resonance Raman (rR), have been useful tools in providing multifaceted and detailed mechanistic insights into the biophysics and biochemistry of these fascinating enzymes. The combination of spectroscopic techniques with novel approaches, such as cryoreduction and Nanodisc technology, allowed for generation, trapping and characterizing long sought transient intermediates, a task that has been difficult to achieve using other methods. Results obtained from the UV-Vis, rR and EPR spectroscopies are the main focus of this review, while the remaining spectroscopic techniques are briefly summarized. This article is part of a Special Issue entitled: Cytochrome P450 biodiversity and biotechnology, edited by Erika Plettner, Gianfranco Gilardi, Luet Wong, Vlada Urlacher, Jared Goldstone.
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Affiliation(s)
- Piotr J Mak
- Department of Chemistry, Saint Louis University, St. Louis, MO, United States.
| | - Ilia G Denisov
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL, United States.
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5
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Adam SM, Garcia-Bosch I, Schaefer AW, Sharma SK, Siegler MA, Solomon EI, Karlin KD. Critical Aspects of Heme-Peroxo-Cu Complex Structure and Nature of Proton Source Dictate Metal-O(peroxo) Breakage versus Reductive O-O Cleavage Chemistry. J Am Chem Soc 2017; 139:472-481. [PMID: 28029788 PMCID: PMC5274545 DOI: 10.1021/jacs.6b11322] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The 4H+/4e- reduction of O2 to water, a key fuel-cell reaction also carried out in biology by oxidase enzymes, includes the critical O-O bond reductive cleavage step. Mechanistic investigations on active-site model compounds, which are synthesized by rational design to incorporate systematic variations, can focus on and resolve answers to fundamental questions, including protonation and/or H-bonding aspects, which accompany electron transfer. Here, we describe the nature and comparative reactivity of two low-spin heme-peroxo-Cu complexes, LS-4DCHIm, [(DCHIm)F8FeIII-(O22-)-CuII(DCHIm)4]+, and LS-3DCHIm, [(DCHIm)F8FeIII-(O22-)-CuII(DCHIm)3]+ (F8 = tetrakis(2,6-difluorophenyl)-porphyrinate; DCHIm = 1,5-dicyclohexylimidazole), toward different proton (4-nitrophenol and [DMF·H+](CF3SO3-)) (DMF = dimethyl-formamide) or electron (decamethylferrocene (Fc*)) sources. Spectroscopic reactivity studies show that differences in structure and electronic properties of LS-3DCHIm and LS-4DCHIm lead to significant differences in behavior. LS-3DCHIm is resistant to reduction, is unreactive toward weakly acidic 4-NO2-phenol, and stronger acids cleave the metal-O bonds, releasing H2O2. By contrast, LS-4DCHIm forms an adduct with 4-NO2-phenol, which includes an H-bond to the peroxo O-atom distal to Fe (resonance Raman (rR) spectroscopy and DFT). With addition of Fc* (2 equiv overall required), O-O reductive cleavage occurs, giving water, Fe(III), and Cu(II) products; however, a kinetic study reveals a one-electron rate-determining process, ket = 1.6 M-1 s-1 (-90 °C). The intermediacy of a high-valent [(DCHIm)F8FeIV═O] species is thus implied, and separate experiments show that one-electron reduction-protonation of [(DCHIm)F8FeIV═O] occurs faster (ket2 = 5.0 M-1 s-1), consistent with the overall postulated mechanism. The importance of the H-bonding interaction as a prerequisite for reductive cleavage is highlighted.
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Affiliation(s)
- Suzanne M. Adam
- Johns Hopkins University, Baltimore, Maryland 21218, United States
| | | | - Andrew W. Schaefer
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Savita K. Sharma
- Johns Hopkins University, Baltimore, Maryland 21218, United States
| | | | - Edward I. Solomon
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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Mak PJ, Thammawichai W, Wiedenhoeft D, Kincaid JR. Resonance Raman Spectroscopy Reveals pH-Dependent Active Site Structural Changes of Lactoperoxidase Compound 0 and Its Ferryl Heme O–O Bond Cleavage Products. J Am Chem Soc 2014; 137:349-61. [DOI: 10.1021/ja5107833] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Piotr J. Mak
- Department
of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Warut Thammawichai
- Department
of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Dennis Wiedenhoeft
- Department
of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - James R. Kincaid
- Department
of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, United States
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7
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Mak PJ, Luthra A, Sligar SG, Kincaid JR. Resonance Raman spectroscopy of the oxygenated intermediates of human CYP19A1 implicates a compound i intermediate in the final lyase step. J Am Chem Soc 2014; 136:4825-8. [PMID: 24645879 PMCID: PMC3985783 DOI: 10.1021/ja500054c] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
CYP19A1, or aromatase,
a cytochrome P450 responsible for estrogen
biosynthesis in humans, is an important therapeutic target for the
treatment of breast cancer. There is still controversy surrounding
the identity of reaction intermediate that catalyzes carbon–carbon
scission in this key enzyme. Probing the oxy-complexes of CYP19A1
poised for hydroxylase and lyase chemistries using resonance Raman
spectroscopy and drawing a comparison with CYP17A1, we have found
no significant difference in the frequencies or isotopic shifts for
these two steps in CYP19A1. Our experiments implicate the involvement
of Compound I in the terminal lyase step of CYP19A1 catalysis.
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Affiliation(s)
- Piotr J Mak
- Department of Chemistry, Marquette University , Milwaukee, Wisconsin 53233, United States
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8
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Gelalcha FG. Biomimetic Iron-Catalyzed Asymmetric Epoxidations: Fundamental Concepts, Challenges and Opportunities. Adv Synth Catal 2014. [DOI: 10.1002/adsc.201300716] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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9
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Mak PJ, Gregory MC, Sligar SG, Kincaid JR. Resonance Raman spectroscopy reveals that substrate structure selectively impacts the heme-bound diatomic ligands of CYP17. Biochemistry 2014; 53:90-100. [PMID: 24328388 PMCID: PMC3922198 DOI: 10.1021/bi4014424] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An important function of steroidogenic cytochromes P450 is the transformation of cholesterol to produce androgens, estrogens, and the corticosteroids. The activities of cytochrome P450c17 (CYP17) are essential in sex hormone biosynthesis, with severe developmental defects being a consequence of deficiency or mutations. The first reaction catalyzed by this multifunctional P450 is the 17α-hydroxylation of pregnenolone (PREG) to 17α-hydroxypregnenolone (17-OH PREG) and progesterone (PROG) to 17α-hydroxyprogesterone (17-OH PROG). The hydroxylated products then either are used for production of corticoids or undergo a second CYP17 catalyzed transformation, representing the first committed step of androgen formation. While the hydroxylation reactions are catalyzed by the well-known Compound I intermediate, the lyase reaction is believed to involve nucleophilic attack of the earlier peroxo- intermediate on the C20-carbonyl. Herein, resonance Raman (rR) spectroscopy reveals that substrate structure does not impact heme structure for this set of physiologically important substrates. On the other hand, rR spectra obtained here for the ferrous CO adducts with these four substrates show that substrates do interact differently with the Fe-C-O fragment, with large differences between the spectra obtained for the samples containing 17-OH PROG and 17-OH PREG, the latter providing evidence for the presence of two Fe-C-O conformers. Collectively, these results demonstrate that individual substrates can differentially impact the disposition of a heme-bound ligand, including dioxygen, altering the reactivity patterns in such a way as to promote preferred chemical conversions, thereby avoiding the profound functional consequences of unwanted side reactions.
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Affiliation(s)
- Piotr J. Mak
- Department of Chemistry, Marquette University, Milwaukee, WI 53233
| | | | - Stephen G. Sligar
- Department of Biochemistry, University of Illinois, Urbana, IL, 61801
- Department of Chemistry, University of Illinois, Urbana, IL, 61801
- College of Medicine, University of Illinois, Urbana, IL, 61801
| | - James R. Kincaid
- Department of Chemistry, Marquette University, Milwaukee, WI 53233
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Mak PJ, Zhu Q, Kincaid JR. Using resonance Raman cross-section data to estimate the spin state populations of Cytochromes P450. JOURNAL OF RAMAN SPECTROSCOPY : JRS 2013; 44:1792-1794. [PMID: 24443630 PMCID: PMC3891783 DOI: 10.1002/jrs.4401] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The cytochromes P450 (CYPs) are heme proteins responsible for the oxidation of xenobiotics and pharmaceuticals and the biosynthesis of essential steroid products. In all cases, substrate binding initiates the enzymatic cycle, converting ferric low spin (LS) to high-spin (HS), with the efficiency of the conversion varying widely for different substrates, so documentation of this conversion for a given substrate is an important objective. Resonance Raman (rR) spectroscopy can effectively yield distinctive frequencies for the ν3 "spin state marker" bands. Here, employing a reference cytochrome P450 (CYP101), the intensities of the ν3 modes (ILS) and (IHS) relative to an internal standard (sodium sulfate) yield relative populations for the two spin states; i.e., a value of 1.24 was determined for the ratio of the relative cross sections for the ν3 modes. Use of this value was then shown to permit a reliable calculation of relative populations of the two spin states from rR spectra of several other Cytochromes P450. The importance of this work is that, using this information, it is now possible to conveniently document by rR the spin state population without conducting separate experiments requiring different analytical methods, instrumentation and additional sample.
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Gregory M, Mak PJ, Sligar SG, Kincaid JR. Differential Hydrogen Bonding in Human CYP17 Dictates Hydroxylation versus Lyase Chemistry. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201300760] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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12
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Gregory M, Mak PJ, Sligar SG, Kincaid JR. Differential hydrogen bonding in human CYP17 dictates hydroxylation versus lyase chemistry. Angew Chem Int Ed Engl 2013; 52:5342-5. [PMID: 23576395 DOI: 10.1002/anie.201300760] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Michael Gregory
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA
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13
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Luthra A, Denisov IG, Sligar SG. Spectroscopic features of cytochrome P450 reaction intermediates. Arch Biochem Biophys 2010; 507:26-35. [PMID: 21167809 DOI: 10.1016/j.abb.2010.12.008] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 12/06/2010] [Accepted: 12/07/2010] [Indexed: 11/24/2022]
Abstract
Cytochromes P450 constitute a broad class of heme monooxygenase enzymes with more than 11,500 isozymes which have been identified in organisms from all biological kingdoms [1]. These enzymes are responsible for catalyzing dozens chemical oxidative transformations such as hydroxylation, epoxidation, N-demethylation, etc., with very broad range of substrates [2,3]. Historically these enzymes received their name from 'pigment 450' due to the unusual position of the Soret band in UV-vis absorption spectra of the reduced CO-saturated state [4,5]. Despite detailed biochemical characterization of many isozymes, as well as later discoveries of other 'P450-like heme enzymes' such as nitric oxide synthase and chloroperoxidase, the phenomenological term 'cytochrome P450' is still commonly used as indicating an essential spectroscopic feature of the functionally active protein which is now known to be due to the presence of a thiolate ligand to the heme iron [6]. Heme proteins with an imidazole ligand such as myoglobin and hemoglobin as well as an inactive form of P450 are characterized by Soret maxima at 420nm [7]. This historical perspective highlights the importance of spectroscopic methods for biochemical studies in general, and especially for heme enzymes, where the presence of the heme iron and porphyrin macrocycle provides rich variety of specific spectroscopic markers available for monitoring chemical transformations and transitions between active intermediates of catalytic cycle.
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Affiliation(s)
- Abhinav Luthra
- Department of Biochemistry, School of Molecular and Cellular Biology, University of Illinois, Urbana, IL 61801, USA
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Active intermediates in heme monooxygenase reactions as revealed by cryoreduction/annealing, EPR/ENDOR studies. Arch Biochem Biophys 2010; 507:36-43. [PMID: 20854788 DOI: 10.1016/j.abb.2010.09.013] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Revised: 09/13/2010] [Accepted: 09/14/2010] [Indexed: 11/21/2022]
Abstract
This review describes the use of cryoreduction/annealing EPR/ENDOR techniques for determining the active oxidizing species in reactions catalyzed by heme monooxygenases. The three candidate heme states are: ferric peroxo, ferric hydroperoxo and compound I intermediates. The enzymes discussed include cytochromes P450, nitric oxide synthase and heme oxygenase.
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15
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Hamdane D, Zhang H, Hollenberg P. Oxygen activation by cytochrome P450 monooxygenase. PHOTOSYNTHESIS RESEARCH 2008; 98:657-66. [PMID: 18600471 PMCID: PMC2743973 DOI: 10.1007/s11120-008-9322-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2008] [Accepted: 06/11/2008] [Indexed: 05/18/2023]
Abstract
Unlike photosystem II (PSII) that catalyzes formation of the O-O bond, the cytochromes P450 (P450), members of a superfamily of hemoproteins, catalyze the scission of the O-O bond of dioxygen molecules and insert a single oxygen atom into unactivated hydrocarbons through a hydrogen abstraction-oxygen rebound mechanism. Hydroxylation of the unactivated hydrocarbons at physiological temperatures is vital for many cellar processes such as the biosynthesis of many endogenous compounds and the detoxification of xenobiotics in humans and plants. Even though it carries out the opposite of the water splitting reaction, P450 may share similarities to PSII in proton delivery networks, oxygen and water access channels, and consecutive electron transfer processes. In this article, we review recent advances in understanding the molecular mechanisms by which P450 activates dioxygen.
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Affiliation(s)
- Djemel Hamdane
- Department of Pharmacology and Department of Anesthesiology, The University of Michigan, Ann Arbor, MI 48109, USA
| | - Haoming Zhang
- Department of Pharmacology and Department of Anesthesiology, The University of Michigan, Ann Arbor, MI 48109, USA
| | - Paul Hollenberg
- Department of Pharmacology and Department of Anesthesiology, The University of Michigan, Ann Arbor, MI 48109, USA
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16
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Isin EM, Guengerich FP. Substrate binding to cytochromes P450. Anal Bioanal Chem 2008; 392:1019-30. [PMID: 18622598 DOI: 10.1007/s00216-008-2244-0] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 06/10/2008] [Accepted: 06/11/2008] [Indexed: 01/08/2023]
Abstract
P450s have attracted tremendous attention owing to not only their involvement in the metabolism of drug molecules and endogenous substrates but also the unusual nature of the reaction they catalyze, namely, the oxidation of unactivated C-H bonds. The binding of substrates to P450s, which is usually viewed as the first step in the catalytic cycle, has been studied extensively via a variety of biochemical and biophysical approaches. These studies were directed towards answering different questions related to P450s, including mechanism of oxidation, substrate properties, unusual substrate oxidation kinetics, function, and active-site features. Some of the substrate binding studies extending over a period of more than 40 years of dedicated work have been summarized in this review and categorized by the techniques employed in the binding studies.
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Affiliation(s)
- Emre M Isin
- Biotransformation Section, Department of Discovery DMPK & Bioanalytical Chemistry, AstraZeneca R & D Mölndal, 431 83, Mölndal, Sweden.
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