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Richard AM, Estrada DF, Flynn L, Pochapsky SS, Scott EE, Pochapsky TC. Tracking protein-protein interactions by NMR: conformational selection in human steroidogenic cytochrome P450 CYP17A1 induced by cytochrome b5. Phys Chem Chem Phys 2024; 26:16980-16988. [PMID: 38842434 PMCID: PMC11186455 DOI: 10.1039/d4cp01268b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 05/26/2024] [Indexed: 06/07/2024]
Abstract
The human steroidogenic cytochrome P450 CYP17A1 catalyzes two types of reactions in the biosynthetic pathway leading from pregnenolone to testosterone and several other steroid hormones. The first is the hydroxylation of pregnenolone or progesterone to the corresponding 17α-hydroxy steroid, followed by a lyase reaction that converts these 17α-hydroxy intermediates to the androgens dehydroepiandrosterone and androstenedione, respectively. cytochrome b5 (cytb5) is known to act as both an effector and electron donor for the lyase oxidations, markedly stimulating the rate of the lyase reaction in its presence relative to the rate in its absence. Extensive sequential backbone 1H,15N and 13C nuclear magnetic resonance assignments have now been made for oxidized CYP17A1 bound to the prostate cancer drug and inhibitor abiraterone. This is the first eukaryotic P450 for which such assignments are now available. These assignments allow more complete interpretation of the structural perturbations observed upon cytb5 addition. Possible mechanism(s) for the effector activity of cytb5 are discussed in light of this new information.
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Affiliation(s)
- Alaina M Richard
- Chemical Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - D Fernando Estrada
- Department of Medicinal Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, USA
| | - Liam Flynn
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, USA.
| | - Susan Sondej Pochapsky
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, USA.
| | - Emily E Scott
- Chemical Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Medicinal Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, USA
- Departments of Medicinal Chemistry, Pharmacology, and Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Thomas C Pochapsky
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, USA.
- Department of Biochemistry and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, 415 South St., Waltham, MA 02454-9110, USA
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Rao P, Yaroslavsky MA, Miller JC, Schuler MA. Catalytic Site Constraints in the P450s Mediating Loganic Acid (7DLH) and Secologanic Acid Synthesis (SLAS) in Camptotheca. Biochemistry 2023; 62:2763-2774. [PMID: 37656055 DOI: 10.1021/acs.biochem.3c00126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Terpene indole alkaloids (TIAs) are plant-derived natural products synthesized in low levels in medicinal plants such as Catharanthus roseus and Camptotheca acuminata. TIA pathways species utilize several CYP72A subfamily members to form loganic acid from 7-deoxyloganic acid (a simple hydroxylation) as well as secologanin and secologanic acid from loganin and loganic acid (a C-C bond scission). Divergences in the specificities of these P450s have allowed Camptotheca secologanic acid synthases (SLASs) to become bifunctional enzymes capable of performing both reactions. In contrast, Catharanthus 7-deoxyloganic acid hydroxylase (7DLH) and secologanin synthase (SLS) have remained monofunctional enzymes capable either of monooxygenation or C-C bond scission. Our in vitro reconstitutions have now demonstrated that Camptotheca also contains a monofunctional 7DLH capable only of hydroxylating 7-deoxyloganic acid. Mutageneses aimed at evaluating residues important for the tight specificity of Camptotheca 7DLH (CYP72A729) and the broad specificity of SLAS (CYP72A564) have identified several residues where reciprocal switches substantially affect their activities: Lys128His in 7DLH increases hydroxylation of 7-deoxyloganic acid, and His132Lys in SLAS decreases this hydroxylation and C-C bond scissions of loganic acid and loganin; Gly321Ser in 7DLH does not affect hydroxylation of 7-deoxyloganic acid, whereas Ser324Gly in SLAS significantly increases C-C bond scission of loganic acid; Asp332Glu in the acid-alcohol pair of 7DLH increases hydroxylation of 7-deoxyloganic acid, whereas Glu335Asp in SLAS completely eliminates both of its activities. These mutations that enhance or eliminate these respective activities have significant potential to aid engineering efforts aimed at increasing TIA production in cell cultures, microbial systems, and/or other plants.
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Affiliation(s)
- Priya Rao
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Mark A Yaroslavsky
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Justin C Miller
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Mary A Schuler
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Plant Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
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Wong NR, Sundar R, Kazanis S, Biswas J, Pochapsky TC. Conformational heterogeneity suggests multiple substrate binding modes in CYP106A2. J Inorg Biochem 2023; 241:112129. [PMID: 36731370 PMCID: PMC9992128 DOI: 10.1016/j.jinorgbio.2023.112129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/16/2022] [Accepted: 01/14/2023] [Indexed: 01/20/2023]
Abstract
CYP106A2 (cytochrome P450meg) is a bacterial enzyme originally isolated from B. megaterium, and has been shown to hydroxylate a wide variety of substrates, including steroids. The regio- and stereochemistry of CYP106A2 hydroxylation has been shown to be dependent on a variety of factors, and hydroxylation often occurs at more than one site and/or with lack of stereospecificity for some substrates. Comprehensive backbone 15N, 1H and 13C resonance assignments based on multidimensional nuclear magnetic resonance (NMR) experiments performed with uniform and selective isotopically labeled CYP106A2 samples are reported herein, and broadening and splitting of resonances assigned to regions of the enzyme shown to be affected by substrate binding in other P450 enzymes indicate that substrate binding does not reduce structural heterogeneity as has been observed previously in P450 enzymes CYP101A1 and MycG. Paramagnetic relaxation enhancement (PRE) due to proximity between substrate protons and the heme iron were measured for three different substrates, and the relatively uniform nature of the PREs support the proposal that multiple substrate binding modes are occupied at saturating substrate concentrations.
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Affiliation(s)
- Nathan R Wong
- Dept. of Biochemistry, Brandeis University, 415 South St., Waltham, MA 02454, United States of America
| | - Reethy Sundar
- Dept. of Biochemistry, Brandeis University, 415 South St., Waltham, MA 02454, United States of America
| | - Sophia Kazanis
- Dept. of Chemistry, Brandeis University, MS 015, 415 South St., Waltham, MA 02454, United States of America; Middlesex Community College, 33 Kearney Sq., Lowell, MA 01852, United States of America
| | - Jeetayu Biswas
- Dept. of Chemistry, Brandeis University, MS 015, 415 South St., Waltham, MA 02454, United States of America; Department of Medicine, Weill-Cornell Medicine, New York, NY, United States of America
| | - Thomas C Pochapsky
- Dept. of Biochemistry, Brandeis University, 415 South St., Waltham, MA 02454, United States of America; Dept. of Chemistry, Brandeis University, MS 015, 415 South St., Waltham, MA 02454, United States of America; Rosenstiel Center for Basic Biomedical Research, Brandeis University, 415 South St., Waltham, MA 02454, United States of America.
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4
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Miller JC, Schuler MA. Single mutations toggle the substrate selectivity of multifunctional Camptotheca secologanic acid synthases (CYP72As). J Biol Chem 2022; 298:102237. [PMID: 35809640 PMCID: PMC9424959 DOI: 10.1016/j.jbc.2022.102237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 11/24/2022] Open
Abstract
Terpene indole alkaloids (TIAs) are plant-derived specialized metabolites with widespread use in medicine. Species-specific pathways derive various TIAs from common intermediates, strictosidine or strictosidinic acid, produced by coupling tryptamine with secologanin or secologanic acid. The penultimate reaction in this pathway is catalyzed by either secologanin synthase (SLS) or secologanic acid synthase (SLAS) according to whether plants produce secologanin from loganin or secologanic acid from loganic acid. Previous work has identified SLSs and SLASs from different species, but the determinants of selectivity remain unclear. Here, combining molecular modeling, ancestral sequence reconstruction, and biochemical methodologies, we identified key residues that toggle SLS and SLAS selectivity in two CYP72A (cytochrome P450) subfamily enzymes from Camptotheca acuminata. We found that the positions of foremost importance are in substrate recognition sequence 1 (SRS1), where mutations to either of two adjacent histidine residues switched selectivity; His131Phe selects for and increases secologanin production whereas His132Asp selects for secologanic acid production. Furthermore, a change in SRS3 in the predicted substrate entry channel (Arg/Lys270Thr) and another in SRS4 at the start of the I-helix (Ser324Glu) decreased enzyme activity toward either substrate. We propose that the Camptotheca SLASs have maintained the broadened activities found in a common asterid ancestor, even as the Camptotheca lineage lost its ability to produce loganin while the campanulid and lamiid lineages specialized to produce secologanin by acquiring mutations in SRS1. The identification here of the residues essential for the broad substrate scope of SLASs presents opportunities for more tailored heterologous production of TIAs.
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Affiliation(s)
- Justin C Miller
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois, USA 61801
| | - Mary A Schuler
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA 61801; Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, Illinois, USA 61801; Department of Plant Biology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA 61801.
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Monk BC, Keniya MV. Roles for Structural Biology in the Discovery of Drugs and Agrochemicals Targeting Sterol 14α-Demethylases. J Fungi (Basel) 2021; 7:67. [PMID: 33498194 PMCID: PMC7908997 DOI: 10.3390/jof7020067] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/08/2021] [Accepted: 01/17/2021] [Indexed: 02/06/2023] Open
Abstract
Antifungal drugs and antifungal agrochemicals have significant limitations. These include several unintended consequences of their use including the growing importance of intrinsic and acquired resistance. These problems underpin an increasingly urgent need to improve the existing classes of antifungals and to discover novel antifungals. Structural insights into drug targets and their complexes with both substrates and inhibitory ligands increase opportunity for the discovery of more effective antifungals. Implementation of this promise, which requires multiple skill sets, is beginning to yield candidates from discovery programs that could more quickly find their place in the clinic. This review will describe how structural biology is providing information for the improvement and discovery of inhibitors targeting the essential fungal enzyme sterol 14α-demethylase.
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Affiliation(s)
- Brian C. Monk
- Department of Oral Sciences, Sir John Walsh Research Institute, University of Otago, Dunedin 9016, New Zealand;
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Abstract
The regulation of brain cytochrome P450 enzymes (CYPs) is different compared with respective hepatic enzymes. This may result from anatomical bases and physiological functions of the two organs. The brain is composed of a variety of functional structures built of different interconnected cell types endowed with specific receptors that receive various neuronal signals from other brain regions. Those signals activate transcription factors or alter functioning of enzyme proteins. Moreover, the blood-brain barrier (BBB) does not allow free penetration of all substances from the periphery into the brain. Differences in neurotransmitter signaling, availability to endogenous and exogenous active substances, and levels of transcription factors between neuronal and hepatic cells lead to differentiated expression and susceptibility to the regulation of CYP genes in the brain and liver. Herein, we briefly describe the CYP enzymes of CYP1-3 families, their distribution in the brain, and discuss brain-specific regulation of CYP genes. In parallel, a comparison to liver CYP regulation is presented. CYP enzymes play an essential role in maintaining the levels of bioactive molecules within normal ranges. These enzymes modulate the metabolism of endogenous neurochemicals, such as neurosteroids, dopamine, serotonin, melatonin, anandamide, and exogenous substances, including psychotropics, drugs of abuse, neurotoxins, and carcinogens. The role of these enzymes is not restricted to xenobiotic-induced neurotoxicity, but they are also involved in brain physiology. Therefore, it is crucial to recognize the function and regulation of CYP enzymes in the brain to build a foundation for future medicine and neuroprotection and for personalized treatment of brain diseases.
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Affiliation(s)
- Wojciech Kuban
- Department of Pharmacokinetics and Drug Metabolism, Maj Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Władysława Anna Daniel
- Department of Pharmacokinetics and Drug Metabolism, Maj Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
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7
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Pochapsky TC. A dynamic understanding of cytochrome P450 structure and function through solution NMR. Curr Opin Biotechnol 2020; 69:35-42. [PMID: 33360373 DOI: 10.1016/j.copbio.2020.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/17/2020] [Indexed: 12/12/2022]
Abstract
Many economically important biosyntheses incorporate regiospecific and stereospecific oxidations at unactivated carbons. Such oxidations are commonly catalyzed by cytochrome P450 monooxygenases, heme-containing enzymes that activate molecular oxygen while selectively binding and orienting the substrate for reaction. Despite the plethora of P450-catalyzed reactions, the P450 fold is highly conserved, and static structures are often insufficient for characterizing conformational states that contribute to specificity. High-resolution solution nuclear magnetic resonance (NMR) offers insights into dynamic processes and conformational changes that are required of a P450 in order to attain the combination of specificity and efficiency required for these reactions.
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Affiliation(s)
- Thomas C Pochapsky
- Departments of Chemistry, Biochemistry and The Rosenstiel Institute for Basic Medical Research, Brandeis University, 415 South St., Waltham, MA 02454, USA.
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8
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Fürst MJLJ, Fiorentini F, Fraaije MW. Beyond active site residues: overall structural dynamics control catalysis in flavin-containing and heme-containing monooxygenases. Curr Opin Struct Biol 2019; 59:29-37. [DOI: 10.1016/j.sbi.2019.01.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 01/25/2019] [Indexed: 12/31/2022]
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Abstract
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Enzyme function requires that enzyme structures be dynamic. Substrate
binding, product release, and transition state stabilization typically
involve different enzyme conformers. Furthermore, in multistep enzyme-catalyzed
reactions, more than one enzyme conformation may be important for
stabilizing different transition states. While X-ray crystallography
provides the most detailed structural information of any current methodology,
X-ray crystal structures of enzymes capture only those conformations
that fit into the crystal lattice, which may or may not be relevant
to function. Solution nuclear magnetic resonance (NMR) methods can
provide an alternative approach to characterizing enzymes under nonperturbing
and controllable conditions, allowing one to identify and localize
dynamic processes that are important to function. However, many enzymes
are too large for standard approaches to making sequential resonance
assignments, a critical first step in analyzing and interpreting the
wealth of information inherent in NMR spectra. This Account
describes our long-standing NMR-based research into
structural and dynamic aspects of function in the cytochrome P450
monooxygenase superfamily. These heme-containing enzymes typically
catalyze the oxidation of unactivated C–H and C=C bonds
in a multitude of substrates, often with complete regio- and stereospecificity.
Over 600 000 genes in GenBank have been assigned to P450s,
yet all known P450 structures exhibit a highly conserved and unique
fold. This combination of functional and structural conservation with
a vast substrate clientele, each substrate having multiple possible
sites for oxidation, makes the P450s a unique target for understanding
the role of enzyme structure and dynamics in determining a particular
substrate–product combination. P450s are large by solution
NMR standards, requiring us to develop specialized approaches for
making sequential resonance assignments and interpreting the spectral
changes that occur as a function of changing conditions (e.g., oxidation
and spin state changes, ligand, substrate or effector binding). Solution
conformations are characterized by the fitting of residual dipolar
couplings (RDCs) measured for sequence-specifically assigned amide
N–H correlations to alignment tensors optimized in the course
of restrained molecular dynamics (MD) simulations. The conformational
ensembles obtained by such RDC-restrained simulations, which we call
“soft annealing”, are then tested by site-directed mutation
and spectroscopic and activity assays for relevance. These efforts
have gained us insights into cryptic conformational changes associated
with substrate and redox partner binding that were not suspected from
crystal structures, but were shown by subsequent work to be relevant
to function. Furthermore, it appears that many of these changes can
be generalized to P450s besides those that we have characterized,
providing guidance for enzyme engineering efforts. While past research
was primarily directed at the more tractable prokaryotic P450s, our
current efforts are aimed at medically relevant human enzymes, including
CYP17A1, CYP2D6, and CYP3A4.
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10
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Wong NR, Liu X, Lloyd H, Colthart AM, Ferrazzoli AE, Cooper DL, Zhuang Y, Esquea P, Futcher J, Pochapsky TM, Matthews JM, Pochapsky TC. A new approach to understanding structure-function relationships in cytochromes P450 by targeting terpene metabolism in the wild. J Inorg Biochem 2018; 188:96-101. [PMID: 30170307 DOI: 10.1016/j.jinorgbio.2018.08.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 07/24/2018] [Accepted: 08/03/2018] [Indexed: 01/30/2023]
Abstract
A strategy for elucidating sequence determinants of function in the class of cytochrome P450 (CYP) enzymes that catalyze the first steps of terpene metabolism in wild microbiomes is described. Wild organisms that can use camphor, terpineol, pinene and limonene were isolated from soils rich in coniferous waste. Cell free extracts and growth beers were analyzed by gas chromatography/mass spectrometry to identify primary oxidative metabolites. For one organism, Pseudomonas nitroreducens TPJM, a cytochrome P450 (CYP108B1) isolated from cell free extracts was demonstrated to catalyze the oxidation of α-terpineol in assays combining the native ferredoxin and putidaredoxin reductase, and the resulting oxidation products identified by gas chromatography/mass spectrometry. Shotgun sequencing of PnTPJM identified four candidate P450 genes, including an apparently fragmentary gene with a high degree of homology with the known enzyme CYP108 (P450terp).
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Affiliation(s)
- Nathan R Wong
- Department of Biochemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, United States of America
| | - Xinyue Liu
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, United States of America
| | - Hannah Lloyd
- Department of Biology, Brandeis University, 415 South St., Waltham, MA 02454-9110, United States of America
| | - Allison M Colthart
- Department of Biochemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, United States of America
| | - Alexander E Ferrazzoli
- Department of Biology, Brandeis University, 415 South St., Waltham, MA 02454-9110, United States of America
| | - Deani L Cooper
- Department of Biology, Brandeis University, 415 South St., Waltham, MA 02454-9110, United States of America
| | - Yihao Zhuang
- Department of Biochemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, United States of America
| | - Phillix Esquea
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, United States of America
| | - Jeffrey Futcher
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, United States of America
| | - Theodore M Pochapsky
- Malden Catholic High School, 90 Crystal St., Malden, MA 02148, United States of America
| | - Jeffrey M Matthews
- Malden Catholic High School, 90 Crystal St., Malden, MA 02148, United States of America
| | - Thomas C Pochapsky
- Department of Biochemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, United States of America; Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454-9110, United States of America.
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11
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Asciutto EK, Pochapsky TC. Some Surprising Implications of NMR-directed Simulations of Substrate Recognition and Binding by Cytochrome P450 cam (CYP101A1). J Mol Biol 2018; 430:1295-1310. [PMID: 29596916 DOI: 10.1016/j.jmb.2018.03.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 03/19/2018] [Accepted: 03/19/2018] [Indexed: 02/05/2023]
Abstract
Cytochrome P450cam (CYP101A1) catalyzes the stereospecific 5-exo hydroxylation of d-camphor by molecular oxygen. Previously, residual dipolar couplings measured for backbone amide 1H-15N correlations in both substrate-free and bound forms of CYP101A1 were used as restraints in soft annealing molecular dynamic simulations in order to identify average conformations of the enzyme with and without substrate bound. Multiple substrate-dependent conformational changes remote from the enzyme active site were identified, and site-directed mutagenesis and activity assays confirmed the importance of these changes in substrate recognition. The current work makes use of perturbation response scanning (PRS) and umbrella sampling molecular dynamic of the residual dipolar coupling-derived CYP101A1 structures to probe the roles of remote structural features in enforcing the regio- and stereospecific nature of the hydroxylation reaction catalyzed by CYP101A1. An improper dihedral angle Ψ was defined and used to maintain substrate orientation in the CYP101A1 active site, and it was observed that different values of Ψ result in different PRS response maps. Umbrella sampling methods show that the free energy of the system is sensitive to Ψ, and bound substrate forms an important mechanical link in the transmission of mechanical coupling through the enzyme structure. Finally, a qualitative approach to interpreting PRS maps in terms of the roles of secondary structural features is proposed.
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Affiliation(s)
- Eliana K Asciutto
- School of Science and Technology, UNSAM and CONICET, Campus Migueletes, 25 de Mayo y Francia, Buenos Aires, Argentina
| | - Thomas C Pochapsky
- Department of Chemistry and Rosenstiel Basic Biomedical Sciences Research Institute, MS 015, Brandeis University, 415 South St., Waltham, MA 02454-9110, USA.
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