1
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Knetsch TGJ, Ubbink M. Lipid composition affects the thermal stability of cytochrome P450 3A4 in nanodiscs. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024:184372. [PMID: 39047858 DOI: 10.1016/j.bbamem.2024.184372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Revised: 06/20/2024] [Accepted: 07/16/2024] [Indexed: 07/27/2024]
Abstract
Nanodiscs (NDs), self-assembled lipid bilayers encircled by membrane scaffold proteins (MSPs), offer a versatile platform for the reconstitution of membrane proteins for structural and biochemical investigations. Saturated, isoprenoid lipids are commonly found in thermophiles and have been associated with thermotolerance. To test whether these lipids confer additional stability on ND-incorporated membrane proteins, this study focuses on the thermal stability of human cytochrome P450 3A4 (CYP3A4) inside NDs composed of different phosphocholine lipids: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), and 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC). NDs were characterized using size-exclusion chromatography coupled with multi-angle light scattering (SEC-MALS) and densitometric SDS-PAGE. CYP3A4-DPhPC-NDs were found to comprise three MSP copies instead of the canonical dimer, as reported before for the empty NDs. Rapid, thermally induced unfolding of CYP3A4 inside NDs measured using circular dichroism and differential scanning fluorimetry (nanoDSF) revealed that the CYP3A4 melting temperature was dependent on ND composition. In POPC and DMPC-CYP3A4-NDs the melting temperature was comparable to CYP3A4 without NDs (59 °C). CYP3A4 in DPhPC-NDs showed an increase in melting temperature of 4 °C. Decline in CYP3A4 integrity as well as ND aggregation and disintegration occur at similar rates for all membrane types when subjected to exposure at 37 °C for several hours. The POPC and DMPC- CYP3A4-NDs show significant lipid loss over time, which is not observed for DPhPC-NDs. The results demonstrate that thermally induced denaturation of protein-NDs is a complex, multifaceted process, which is not represented well by rapid thermal unfolding experiments.
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Affiliation(s)
- Tim G J Knetsch
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, the Netherlands
| | - Marcellus Ubbink
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, the Netherlands.
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2
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Fu T, Zhang H, Zheng Q. Assessing the role of residue Phe108 of cytochrome P450 3A4 in allosteric effects of midazolam metabolism. Phys Chem Chem Phys 2024; 26:8807-8814. [PMID: 38421040 DOI: 10.1039/d3cp05270b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Cytochrome P450 3A4 (CYP3A4) is involved in the metabolism of more drugs in clinical use than any other xenobiotic-metabolizing enzyme. CYP3A4-mediated drug metabolism is usually allosterically modulated by substrate concentration (homotropic allostery) and other drugs (heterotropic allostery), exhibiting unusual kinetic profiles and regiospecific metabolism. Recent studies suggest that residue Phe108 (F108) of CYP3A4 may have an important role in drug metabolism. In this work, residue mutations were coupled with well-tempered metadynamics simulations to assess the importance of F108 in the allosteric effects of midazolam metabolism. Comparing the simulation results of the wild-type and mutation systems, we identify that the π-π interaction and steric effect between the F108 side chain and midazolam is favorable for the stable binding of substrate in the active site. F108 also plays an important role in the transition of substrate binding mode, which mainly induces the transition of substrate binding mode by forming π-π interactions with multiple aromatic rings of the substrate. Moreover, the side chain of F108 is closely related to the radius and depth of the 2a and 2f channels, and F108 may further regulate drug metabolism by affecting the pathway, orientation, or time of substrate entry into the CYP3A4 active site or product egress from the active site. Altogether, we suggest that F108 affects drug metabolism and regulatory mechanisms by affecting substrate binding stability, binding mode transition, and channel characteristics of CYP3A4. Our findings could promote the understanding of complicated allosteric mechanisms in CYP3A4-mediated drug metabolism, and the knowledge could be used for drug development and disease treatment.
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Affiliation(s)
- Tingting Fu
- School of Pharmaceutical Sciences, Jilin University, Changchun, 130021, China.
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130023, China
| | - Hongxing Zhang
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130023, China
| | - Qingchuan Zheng
- School of Pharmaceutical Sciences, Jilin University, Changchun, 130021, China.
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130023, China
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3
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Kaluzhskiy L, Yablokov E, Gnedenko O, Burkatovskii D, Maslov I, Bogorodskiy A, Ershov P, Tsybruk T, Zelepuga E, Rutckova T, Kozlovskaya E, Dmitrenok P, Gilep A, Borshchevskiy V, Strushkevich N, Ivanov A. The effect of membrane composition on the interaction between human CYP51 and its flavonoid inhibitor - luteolin 7,3'-disulfate. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184286. [PMID: 38272204 DOI: 10.1016/j.bbamem.2024.184286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/22/2023] [Accepted: 01/16/2024] [Indexed: 01/27/2024]
Abstract
Cytochromes P450 (CYP) are a family of membrane proteins involved in the production of endogenous molecules and the metabolism of xenobiotics. It is well-known that the composition of the membrane can influence the activity and orientation of CYP proteins. However, little is known about how membrane composition affects the ligand binding properties of CYP. In this study, we utilized surface plasmon resonance and fluorescence lifetime analysis to examine the impact of membrane micro-environment composition on the interaction between human microsomal CYP51 (CYP51A1) and its inhibitor, luteolin 7,3'-disulphate (LDS). We observed that membranes containing cholesterol or sphingomyelin exhibited the lowest apparent equilibrium dissociation constant for the CYP51A1-LDS complex. Additionally, the tendency for relation between kinetic parameters of the CYP51A1-LDS complex and membrane viscosity and overall charge was observed. These findings suggest that the specific composition of the membrane, particularly the presence of cholesterol and sphingomyelin, plays a vital role in regulating the interaction between CYP enzymes and their ligands.
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Affiliation(s)
- Leonid Kaluzhskiy
- Institute of Biomedical Chemistry, 10 Building 8, Pogodinskaya Street, 119121 Moscow, Russia.
| | - Evgeniy Yablokov
- Institute of Biomedical Chemistry, 10 Building 8, Pogodinskaya Street, 119121 Moscow, Russia.
| | - Oksana Gnedenko
- Institute of Biomedical Chemistry, 10 Building 8, Pogodinskaya Street, 119121 Moscow, Russia.
| | - Dmitrii Burkatovskii
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia.
| | - Ivan Maslov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia.
| | - Andrey Bogorodskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
| | - Pavel Ershov
- Institute of Biomedical Chemistry, 10 Building 8, Pogodinskaya Street, 119121 Moscow, Russia
| | - Tatsiana Tsybruk
- Institute of Bioorganic Chemistry NASB, 5 Building 2, V.F. Kuprevich Street, 220141 Minsk, Belarus
| | - Elena Zelepuga
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Science, 159 Prospect 100-letiya Vladivostoka, 690022 Vladivostok, Russia.
| | - Tatyana Rutckova
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Science, 159 Prospect 100-letiya Vladivostoka, 690022 Vladivostok, Russia
| | - Emma Kozlovskaya
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Science, 159 Prospect 100-letiya Vladivostoka, 690022 Vladivostok, Russia
| | - Pavel Dmitrenok
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Science, 159 Prospect 100-letiya Vladivostoka, 690022 Vladivostok, Russia.
| | - Andrei Gilep
- Institute of Biomedical Chemistry, 10 Building 8, Pogodinskaya Street, 119121 Moscow, Russia; Institute of Bioorganic Chemistry NASB, 5 Building 2, V.F. Kuprevich Street, 220141 Minsk, Belarus.
| | - Valentin Borshchevskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia; Joint Institute for Nuclear Research, Dubna 141980, Russia
| | - Natallia Strushkevich
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, bld. 1, 121205 Moscow, Russia.
| | - Alexis Ivanov
- Institute of Biomedical Chemistry, 10 Building 8, Pogodinskaya Street, 119121 Moscow, Russia.
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4
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Selvasingh JA, McDonald EF, Neufer PD, McKinney JR, Meiler J, Ledwitch KV. Dark nanodiscs for evaluating membrane protein thermostability by differential scanning fluorimetry. Biophys J 2024; 123:68-79. [PMID: 37978799 PMCID: PMC10808023 DOI: 10.1016/j.bpj.2023.11.019] [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: 05/24/2023] [Revised: 10/27/2023] [Accepted: 11/16/2023] [Indexed: 11/19/2023] Open
Abstract
Measuring protein thermostability provides valuable information on the biophysical rules that govern the structure-energy relationships of proteins. However, such measurements remain a challenge for membrane proteins. Here, we introduce a new experimental system to evaluate membrane protein thermostability. This system leverages a recently developed nonfluorescent membrane scaffold protein to reconstitute proteins into nanodiscs and is coupled with a nano-format of differential scanning fluorimetry (nanoDSF). This approach offers a label-free and direct measurement of the intrinsic tryptophan fluorescence of the membrane protein as it unfolds in solution without signal interference from the "dark" nanodisc. In this work, we demonstrate the application of this method using the disulfide bond formation protein B (DsbB) as a test membrane protein. NanoDSF measurements of DsbB reconstituted in dark nanodiscs loaded with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dimyristoyl-sn-glycero-3-phosphorylglycerol (DMPG) lipids show a complex biphasic thermal unfolding pattern with a minor unfolding transition followed by a major transition. The inflection points of the thermal denaturation curve reveal two distinct unfolding midpoint melting temperatures (Tm) of 70.5°C and 77.5°C, consistent with a three-state unfolding model. Further, we show that the catalytically conserved disulfide bond between residues C41 and C130 drives the intermediate state of the unfolding pathway for DsbB in a DMPC and DMPG nanodisc. To extend the utility of this method, we evaluate and compare the thermostability of DsbB in different lipid environments. We introduce this method as a new tool that can be used to understand how compositionally and biophysically complex lipid environments drive membrane protein stability.
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Affiliation(s)
- Jazlyn A Selvasingh
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee; Department of Chemistry, Vanderbilt University, Nashville, Tennessee
| | - Eli F McDonald
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee; Department of Chemistry, Vanderbilt University, Nashville, Tennessee
| | - Preston D Neufer
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee; Department of Chemistry, Vanderbilt University, Nashville, Tennessee
| | - Jacob R McKinney
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee; Department of Chemistry, Vanderbilt University, Nashville, Tennessee
| | - Jens Meiler
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee; Department of Chemistry, Vanderbilt University, Nashville, Tennessee; Institute of Drug Discovery, Faculty of Medicine, University of Leipzig, Leipzig, Germany.
| | - Kaitlyn V Ledwitch
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee; Department of Chemistry, Vanderbilt University, Nashville, Tennessee.
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5
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Sahoo BR, Ramamoorthy A. Direct interaction between the transmembrane helices stabilize cytochrome P450 2B4 and cytochrome b5 redox complex. Biophys Chem 2023; 301:107092. [PMID: 37586236 PMCID: PMC10838600 DOI: 10.1016/j.bpc.2023.107092] [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: 06/12/2023] [Revised: 08/06/2023] [Accepted: 08/07/2023] [Indexed: 08/18/2023]
Abstract
The catalytic activity of cytochrome P450 2B4 (CYP2B4) is moderated by its cognate redox partner cytochrome b5 (Cyt-b5). The endoplasmic reticulum (ER) membrane and intermolecular transmembrane (TM) interaction between CYP2B4 and Cyt-b5 regulate the substrate catalysis and the reaction rate. This emphasizes the significance of elucidating the molecular basis of CYP2B4 and Cyt-b5 complexation in a membrane environment to better understand the enzymatic activity of CYP2B4. Our previous solid-state NMR studies revealed the membrane topology of the transmembrane domains of these proteins in the free and complex forms. Here, we show the cross-angle complex formation by the single-pass TM domains of CYP2B4 and Cyt-b5, which is mainly driven by several salt-bridges (E2-R128, R21-D104 and K25-D104), using a multi-microsecond molecular dynamic simulation. Additionally, the leucine-zipper residues (L8, L12, L15, L18 and L19 from CYP2B4) and π-stacking between H23 and F20 residues of CYP2B4 and W110 of Cyt-b5 are identified to stabilize the TM-TM complex in the ER membrane. The simulated tilts of the helices in the free and in the complex are in excellent agreement with solid-state NMR results. The TM-TM packing influences a higher order structural stability when compared to the complex formed by the truncated soluble domains of these two proteins. MM/PBSA based binding free energy estimates nearly 100-fold higher binding affinity (ΔG = -2810.68 ± 696.44 kJ/mol) between the soluble domains of the full-length CYP2B4 and Cyt-b5 when embedded in lipid membrane as compared to the TM-domain-truncated soluble domains (ΔG = -27.406 ± 10.32 kJ/mol). The high-resolution full-length CYP2B4-Cyt-b5 complex structure and its dynamics in a native ER membrane environment reported here could aid in the development of approaches to effectively modulate the drug-metabolism activity of CYP2B4.
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Affiliation(s)
- Bikash R Sahoo
- Biophysics Program, Department of Chemistry, Macromolecular Science and Engineering, Biomedical Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, MI 48109-1055, USA.
| | - Ayyalusamy Ramamoorthy
- Biophysics Program, Department of Chemistry, Macromolecular Science and Engineering, Biomedical Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, MI 48109-1055, USA.
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6
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Sweeney DT, Zárate-Pérez F, Stokowa-Sołtys K, Hackett JC. Induced Fit Describes Ligand Binding to Membrane-Associated Cytochrome P450 3A4. Mol Pharmacol 2023; 104:154-163. [PMID: 37536953 PMCID: PMC10506697 DOI: 10.1124/molpharm.123.000698] [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: 03/14/2023] [Revised: 07/06/2023] [Accepted: 07/20/2023] [Indexed: 08/05/2023] Open
Abstract
Cytochrome P450 3A4 (CYP3A4) is the dominant P450 involved in human xenobiotic metabolism. Competition for CYP3A4 therefore underlies several adverse drug-drug interactions. Despite its clinical significance, the mechanisms CYP3A4 uses to bind diverse ligands remain poorly understood. Highly monodisperse CYP3A4 embedded in anionic lipoprotein nanodiscs containing an equal mixture of 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine and 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) were used to determine which of the limiting kinetic schemes that include protein conformational change, conformational selection (CS) or induced fit (IF), best described the binding of four known irreversible inhibitors. Azamulin, retapamulin, pleuromutilin, and mibrefadil binding to CYP3A4 nanodiscs conformed to a single-site binding model. Exponential fits of stopped-flow UV-visible absorption spectroscopy data supported multiple-step binding mechanisms. Trends in the rates of relaxation to equilibrium with increasing ligand concentrations were ambiguous as to whether IF or CS was involved; however, global fitting and consideration of the rate constants favored an IF mechanism. In the case of mibrefadil, a transient complex was observed in the stopped-flow UV-visible experiment, definitively assigning the presence of IF in ligand binding. While these studies only consider a small region of CYP3A4's vast ligand space, they provide kinetic evidence that CYP3A4 can use an IF mechanism. SIGNIFICANCE STATEMENT: CYP3A4 is capable of oxidizing numerous xenobiotics, including many drugs. Such promiscuity could not be achieved without conformational changes to accommodate diverse substrates. It is unknown whether conformational heterogeneity is present before (conformational selection) or after (induced fit) ligand binding. Stopped-flow measurements of suicide inhibitors binding to nanodisc-embedded CYP3A4 combined with sophisticated numerical analyses support that induced fit better describes ligand binding to this important enzyme.
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Affiliation(s)
- David Tyler Sweeney
- Department of Chemistry and Biochemistry and Biomolecular Sciences Institute, Florida International University, Miami, Florida (J.C.H., K.S.S., F.Z.P.); Department of Physiology and Biophysics and The Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia (D.T.S.); and Department of Biological and Medicinal Chemistry, Faculty of Chemistry, University of Wroclaw, Wroclaw, Poland (K.S.S.)
| | - Francisco Zárate-Pérez
- Department of Chemistry and Biochemistry and Biomolecular Sciences Institute, Florida International University, Miami, Florida (J.C.H., K.S.S., F.Z.P.); Department of Physiology and Biophysics and The Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia (D.T.S.); and Department of Biological and Medicinal Chemistry, Faculty of Chemistry, University of Wroclaw, Wroclaw, Poland (K.S.S.)
| | - Kamila Stokowa-Sołtys
- Department of Chemistry and Biochemistry and Biomolecular Sciences Institute, Florida International University, Miami, Florida (J.C.H., K.S.S., F.Z.P.); Department of Physiology and Biophysics and The Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia (D.T.S.); and Department of Biological and Medicinal Chemistry, Faculty of Chemistry, University of Wroclaw, Wroclaw, Poland (K.S.S.)
| | - John C Hackett
- Department of Chemistry and Biochemistry and Biomolecular Sciences Institute, Florida International University, Miami, Florida (J.C.H., K.S.S., F.Z.P.); Department of Physiology and Biophysics and The Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia (D.T.S.); and Department of Biological and Medicinal Chemistry, Faculty of Chemistry, University of Wroclaw, Wroclaw, Poland (K.S.S.)
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7
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Paço L, Hackett JC, Atkins WM. Nanodisc-embedded cytochrome P450 P3A4 binds diverse ligands by distributing conformational dynamics to its flexible elements. J Inorg Biochem 2023; 244:112211. [PMID: 37080138 PMCID: PMC10175226 DOI: 10.1016/j.jinorgbio.2023.112211] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/12/2023] [Accepted: 04/03/2023] [Indexed: 04/22/2023]
Abstract
Cytochrome P450 3A4 (CYP3A4) metabolizes a wide range of drugs and toxins. Interactions of CYP3A4 with ligands are difficult to predict due to promiscuity and conformational flexibility. To better understand CYP3A4 conformational responses to ligands we use hydrogen deuterium exchange mass spectrometry (HDX-MS) to investigate the effect of ligands on nanodisc-embedded CYP3A4. For a subset of CYP3A4-ligand complexes, differences in the low-frequency modes derived by principal component analyses of molecular dynamics trajectories mirrored the HDX-MS results. The effects of ligands are distributed to flexible elements of CYP3A4 between stretches of secondary structure. The largest effects occur in the F- and G-helices, where most ligands increase the flexibility of the F-helix and connecting loops and decrease the flexibility of the C-term of the G-helix. Most ligands affect the E-F-G, CD and HI regions of the protein. Ligand-dependent differences are observed in the A"-A' loop, BC region, E-helix, K-β1 region, proximal loop, and C-term loop. Correlated HDX responses were observed in the CD region and the C-term of the G-helix that were most pronounced for Type II ligands. Collectively, the HDX and molecular dynamics results suggest that CYP3A4 accommodates diverse binding partners by propagating local backbone fluctuations from the binding site onto the flexible regions of the enzyme via long-range interactions that are differentially modulated by ligands. In contrast to the paradigm wherein ligands decrease protein dynamics at their binding site, a wide range of ligands modestly increase CYP3A4 dynamics throughout the protein including effects remote from the active site.
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Affiliation(s)
- Lorela Paço
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195-7610, United States of America
| | - John C Hackett
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States of America
| | - William M Atkins
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195-7610, United States of America.
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8
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Selvasingh JA, McDonald EF, Mckinney JR, Meiler J, Ledwitch KV. Dark nanodiscs as a model membrane for evaluating membrane protein thermostability by differential scanning fluorimetry. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.08.539917. [PMID: 37214798 PMCID: PMC10197605 DOI: 10.1101/2023.05.08.539917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Measuring protein thermostability provides valuable information on the biophysical rules that govern structure-energy relationships of proteins. However, such measurements remain a challenge for membrane proteins. Here, we introduce a new experimental system to evaluate membrane protein thermostability. This system leverages a recently-developed non-fluorescent membrane scaffold protein (MSP) to reconstitute proteins into nanodiscs and is coupled with a nano-format of differential scanning fluorimetry (nanoDSF). This approach offers a label-free and direct measurement of the intrinsic tryptophan fluorescence of the membrane protein as it unfolds in solution without signal interference from the "dark" nanodisc. In this work, we demonstrate the application of this method using the disulfide bond formation protein B (DsbB) as a test membrane protein. NanoDSF measurements of DsbB reconstituted in dark nanodiscs show a complex biphasic thermal unfolding pattern in the presence of lipids with a minor unfolding transition followed by a major transition. The inflection points of the thermal denaturation curve reveal two distinct unfolding midpoint melting temperatures (Tm) of 70.5 °C and 77.5 °C, consistent with a three-state unfolding model. Further, we show that the catalytically conserved disulfide bond between residues C41 and C130 drives the intermediate state of the unfolding pathway for DsbB in a nanodisc. We introduce this method as a new tool that can be used to understand how compositionally, and biophysically complex lipid environments drive membrane protein stability.
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Affiliation(s)
- Jazlyn A. Selvasingh
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Eli Fritz McDonald
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Jacob R. Mckinney
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Jens Meiler
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
- Institute of Drug Discovery, Faculty of Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Kaitlyn V. Ledwitch
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
- Lead contact
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9
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Fu T, Zhang H, Zheng Q. Molecular Insights into the Heterotropic Allosteric Mechanism in Cytochrome P450 3A4-Mediated Midazolam Metabolism. J Chem Inf Model 2022; 62:5762-5770. [PMID: 36342224 DOI: 10.1021/acs.jcim.2c01264] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cytochrome P450 3A4 (CYP3A4) is the main P450 enzyme for drug metabolism and drug-drug interactions (DDIs), as it is involved in the metabolic process of approximately 50% of drugs. A detailed mechanistic elucidation of DDIs mediated by CYP3A4 is commonly believed to be critical for drug optimization and rational use. Here, two typical probes, midazolam (MDZ, substrate) and testosterone (TST, allosteric effector), are used to investigate the molecular mechanism of CYP3A4-mediated heterotropic allosteric interactions, through conventional molecular dynamics (cMD) and well-tempered metadynamics (WT-MTD) simulations. Distance monitoring shows that TST can stably bind in two potential peripheral sites (Site 1 and Site 2) of CYP3A4. The binding of TST at these two sites can induce conformational changes in CYP3A4 flexible loops on the basis of conformational analysis, thereby promoting the transition of the MDZ binding mode and affecting the ratio of MDZ metabolites. According to the results of the residue interaction network, multiple allosteric communication pathways are identified that can provide vivid and applicable insights into the heterotropic allostery of TST on MDZ metabolism. Comparing the regulatory effects and the communication pathways, the allosteric effect caused by TST binding in Site 2 seems to be more pronounced than in Site 1. Our findings could provide a deeper understanding of CYP3A4-mediated heterotropic allostery at the atomic level and would be helpful for rational drug use as well as the design of new allosteric modulators.
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Affiliation(s)
- Tingting Fu
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130023, China
| | - Hongxing Zhang
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130023, China
| | - Qingchuan Zheng
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130023, China.,Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, Jilin University, Changchun 130023, China
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10
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Krishnarjuna B, Ramamoorthy A. Detergent-Free Isolation of Membrane Proteins and Strategies to Study Them in a Near-Native Membrane Environment. Biomolecules 2022; 12:1076. [PMID: 36008970 PMCID: PMC9406181 DOI: 10.3390/biom12081076] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 07/31/2022] [Accepted: 08/02/2022] [Indexed: 02/06/2023] Open
Abstract
Atomic-resolution structural studies of membrane-associated proteins and peptides in a membrane environment are important to fully understand their biological function and the roles played by them in the pathology of many diseases. However, the complexity of the cell membrane has severely limited the application of commonly used biophysical and biochemical techniques. Recent advancements in NMR spectroscopy and cryoEM approaches and the development of novel membrane mimetics have overcome some of the major challenges in this area. For example, the development of a variety of lipid-nanodiscs has enabled stable reconstitution and structural and functional studies of membrane proteins. In particular, the ability of synthetic amphipathic polymers to isolate membrane proteins directly from the cell membrane, along with the associated membrane components such as lipids, without the use of a detergent, has opened new avenues to study the structure and function of membrane proteins using a variety of biophysical and biological approaches. This review article is focused on covering the various polymers and approaches developed and their applications for the functional reconstitution and structural investigation of membrane proteins. The unique advantages and limitations of the use of synthetic polymers are also discussed.
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Affiliation(s)
- Bankala Krishnarjuna
- Department of Chemistry and Biophysics, Biomedical Engineering, Macromolecular Science and Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Ayyalusamy Ramamoorthy
- Department of Chemistry and Biophysics, Biomedical Engineering, Macromolecular Science and Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, MI 48109-1055, USA
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11
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Catucci G, Ciaramella A, Di Nardo G, Zhang C, Castrignanò S, Gilardi G. Molecular Lego of Human Cytochrome P450: The Key Role of Heme Domain Flexibility for the Activity of the Chimeric Proteins. Int J Mol Sci 2022; 23:ijms23073618. [PMID: 35408976 PMCID: PMC8998974 DOI: 10.3390/ijms23073618] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 03/22/2022] [Accepted: 03/24/2022] [Indexed: 02/04/2023] Open
Abstract
The cytochrome P450 superfamily are heme-thiolate enzymes able to carry out monooxygenase reactions. Several studies have demonstrated the feasibility of using a soluble bacterial reductase from Bacillus megaterium, BMR, as an artificial electron transfer partner fused to the human P450 domain in a single polypeptide chain in an approach known as ‘molecular Lego’. The 3A4-BMR chimera has been deeply characterized biochemically for its activity, coupling efficiency, and flexibility by many different biophysical techniques leading to the conclusion that an extension of five glycines in the loop that connects the two domains improves all the catalytic parameters due to improved flexibility of the system. In this work, we extend the characterization of 3A4-BMR chimeras using differential scanning calorimetry to evaluate stabilizing role of BMR. We apply the ‘molecular Lego’ approach also to CYP19A1 (aromatase) and the data show that the activity of the chimeras is very low (<0.003 min−1) for all the constructs tested with a different linker loop length: ARO-BMR, ARO-BMR-3GLY, and ARO-BMR-5GLY. Nevertheless, the fusion to BMR shows a remarkable effect on thermal stability studied by differential scanning calorimetry as indicated by the increase in Tonset by 10 °C and the presence of a cooperative unfolding process driven by the BMR protein domain. Previously characterized 3A4-BMR constructs show the same behavior of ARO-BMR constructs in terms of thermal stabilization but a higher activity as a function of the loop length. A comparison of the ARO-BMR system to 3A4-BMR indicates that the design of each P450-BMR chimera should be carefully evaluated not only in terms of electron transfer, but also for the biophysical constraints that cannot always be overcome by chimerization.
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12
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James EI, Murphree TA, Vorauer C, Engen JR, Guttman M. Advances in Hydrogen/Deuterium Exchange Mass Spectrometry and the Pursuit of Challenging Biological Systems. Chem Rev 2021; 122:7562-7623. [PMID: 34493042 PMCID: PMC9053315 DOI: 10.1021/acs.chemrev.1c00279] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
![]()
Solution-phase hydrogen/deuterium
exchange (HDX) coupled to mass
spectrometry (MS) is a widespread tool for structural analysis across
academia and the biopharmaceutical industry. By monitoring the exchangeability
of backbone amide protons, HDX-MS can reveal information about higher-order
structure and dynamics throughout a protein, can track protein folding
pathways, map interaction sites, and assess conformational states
of protein samples. The combination of the versatility of the hydrogen/deuterium
exchange reaction with the sensitivity of mass spectrometry has enabled
the study of extremely challenging protein systems, some of which
cannot be suitably studied using other techniques. Improvements over
the past three decades have continually increased throughput, robustness,
and expanded the limits of what is feasible for HDX-MS investigations.
To provide an overview for researchers seeking to utilize and derive
the most from HDX-MS for protein structural analysis, we summarize
the fundamental principles, basic methodology, strengths and weaknesses,
and the established applications of HDX-MS while highlighting new
developments and applications.
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Affiliation(s)
- Ellie I James
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Taylor A Murphree
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Clint Vorauer
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - John R Engen
- Department of Chemistry & Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Miklos Guttman
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States
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13
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Ducharme J, Sevrioukova IF, Thibodeaux CJ, Auclair K. Structural Dynamics of Cytochrome P450 3A4 in the Presence of Substrates and Cytochrome P450 Reductase. Biochemistry 2021; 60:2259-2271. [PMID: 34196520 DOI: 10.1021/acs.biochem.1c00178] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cytochrome P450 3A4 (CYP3A4) is the most important drug-metabolizing enzyme in humans and has been associated with harmful drug interactions. The activity of CYP3A4 is known to be modulated by several compounds and by the electron transfer partner, cytochrome P450 reductase (CPR). The underlying mechanism of these effects, however, is poorly understood. We have used hydrogen-deuterium exchange mass spectrometry to investigate the impact of binding of CPR and of three different substrates (7-benzyloxy-4-trifluoromethyl-coumarin, testosterone, and progesterone) on the conformational dynamics of CYP3A4. Here, we report that interaction of CYP3A4 with substrates or with the oxidized or reduced forms of CPR leads to a global rigidification of the CYP3A4 structure. This was evident from the suppression of deuterium exchange in several regions of CYP3A4, including regions known to be involved in protein-protein interactions (helix C) and substrate binding and specificity (helices B' and E, and loop K/β1). Furthermore, the bimodal isotopic distributions observed for some CYP3A4-derived peptides were drastically impacted upon binding to CPR and/or substrates, suggesting the existence of stable CYP3A4 conformational populations that are perturbed by ligand/CPR binding. The results have implications for understanding the mechanisms of ligand binding, allostery, and catalysis in CYP enzymes.
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Affiliation(s)
- Julie Ducharme
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, Canada H3A 0B8
| | - Irina F Sevrioukova
- Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92697, United States
| | - Christopher J Thibodeaux
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, Canada H3A 0B8
| | - Karine Auclair
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, Canada H3A 0B8
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14
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Ducharme J, Polic V, Thibodeaux CJ, Auclair K. Combining Small-Molecule Bioconjugation and Hydrogen-Deuterium Exchange Mass Spectrometry (HDX-MS) to Expose Allostery: the Case of Human Cytochrome P450 3A4. ACS Chem Biol 2021; 16:882-890. [PMID: 33913317 DOI: 10.1021/acschembio.1c00084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We report a novel approach to study allostery which combines the use of carefully selected bioconjugates and hydrogen-deuterium exchange mass spectrometry (HDX-MS). This strategy avoids issues related to weak substrate binding and ligand relocalization. The utility of our method is demonstrated using human cytochrome P450 3A4 (CYP3A4), the most important drug-metabolizing enzyme. Allosteric activation and inhibition of CYP3A4 by pharmaceuticals is an important mechanism of drug interactions. We performed HDX-MS analysis on several CYP3A4-effector bioconjugates, some of which mimic the allosteric effect of positive effectors, while others show activity enhancement even though the label does not occupy the allosteric pocket (agonistic) or do not show activation while still blocking the allosteric site (antagonistic). This allowed us to better define the position of the allosteric site, the protein structural dynamics associated with allosteric activation, and the presence of coexisting conformers.
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Affiliation(s)
- Julie Ducharme
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec, Canada H3A 0B8
| | - Vanja Polic
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec, Canada H3A 0B8
| | - Christopher J. Thibodeaux
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec, Canada H3A 0B8
| | - Karine Auclair
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec, Canada H3A 0B8
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15
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Krishnarjuna B, Yamazaki T, Anantharamaiah GM, Ramamoorthy A. Nanodisc reconstitution of flavin mononucleotide binding domain of cytochrome-P450-reductase enables high-resolution NMR probing. Chem Commun (Camb) 2021; 57:4819-4822. [PMID: 33982687 PMCID: PMC8136615 DOI: 10.1039/d1cc01018b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cytochrome-P450-reductase transfers electrons to cytochrome-P450 through its flavin mononucleotide binding domain (FBD). Despite the importance of membrane-anchoring for FBD function, studies have focused on its soluble domain lacking the transmembrane-domain. Here we demonstrate that the reconstitution of FBD in nanodiscs enables high-resolution NMR measurements and renders a stable conformation.
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Affiliation(s)
- Bankala Krishnarjuna
- Biophysics Program, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, University of Michigan, Arbor, MI 48109, USA.
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16
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Sligar SG, Denisov IG. Nanodiscs: A toolkit for membrane protein science. Protein Sci 2020; 30:297-315. [PMID: 33165998 DOI: 10.1002/pro.3994] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 10/30/2020] [Accepted: 10/30/2020] [Indexed: 12/25/2022]
Abstract
Membrane proteins are involved in numerous vital biological processes, including transport, signal transduction and the enzymes in a variety of metabolic pathways. Integral membrane proteins account for up to 30% of the human proteome and they make up more than half of all currently marketed therapeutic targets. Unfortunately, membrane proteins are inherently recalcitrant to study using the normal toolkit available to scientists, and one is most often left with the challenge of finding inhibitors, activators and specific antibodies using a denatured or detergent solubilized aggregate. The Nanodisc platform circumvents these challenges by providing a self-assembled system that renders typically insoluble, yet biologically and pharmacologically significant, targets such as receptors, transporters, enzymes, and viral antigens soluble in aqueous media in a native-like bilayer environment that maintain a target's functional activity. By providing a bilayer surface of defined composition and structure, Nanodiscs have found great utility in the study of cellular signaling complexes that assemble on a membrane surface. Nanodiscs provide a nanometer scale vehicle for the in vivo delivery of amphipathic drugs, therapeutic lipids, tethered nucleic acids, imaging agents and active protein complexes. This means for generating nanoscale lipid bilayers has spawned the successful use of numerous other polymer and peptide amphipathic systems. This review, in celebration of the Anfinsen Award, summarizes some recent results and provides an inroad into the current and historical literature.
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Affiliation(s)
- Stephen G Sligar
- Departments of Biochemistry Chemistry, University of Illinois, Urbana-Champaign, Urbana, Illinois, USA
| | - Ilia G Denisov
- Departments of Biochemistry Chemistry, University of Illinois, Urbana-Champaign, Urbana, Illinois, USA
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17
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Paço L, Zarate-Perez F, Clouser AF, Atkins WM, Hackett JC. Dynamics and Mechanism of Binding of Androstenedione to Membrane-Associated Aromatase. Biochemistry 2020; 59:2999-3009. [DOI: 10.1021/acs.biochem.0c00460] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Lorela Paço
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195-7610, United States
| | - Francisco Zarate-Perez
- Department of Physiology and Biophysics and Massey Cancer Center, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298-0035, United States
| | - Amanda F. Clouser
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195-7610, United States
| | - William M. Atkins
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195-7610, United States
| | - John C. Hackett
- Department of Physiology and Biophysics and Massey Cancer Center, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298-0035, United States
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18
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Receptor-binding hydrogen–deuterium exchange mass spectrometry as an additional measurement of biosimilarity. JOURNAL OF PHARMACEUTICAL INVESTIGATION 2020. [DOI: 10.1007/s40005-019-00465-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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19
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Jeffreys LN, Pacholarz KJ, Johannissen LO, Girvan HM, Barran PE, Voice MW, Munro AW. Characterization of the structure and interactions of P450 BM3 using hybrid mass spectrometry approaches. J Biol Chem 2020; 295:7595-7607. [PMID: 32303637 PMCID: PMC7261786 DOI: 10.1074/jbc.ra119.011630] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 04/02/2020] [Indexed: 01/08/2023] Open
Abstract
The cytochrome P450 monooxygenase P450 BM3 (BM3) is a biotechnologically important and versatile enzyme capable of producing important compounds such as the medical drugs pravastatin and artemether, and the steroid hormone testosterone. BM3 is a natural fusion enzyme comprising two major domains: a cytochrome P450 (heme-binding) catalytic domain and a NADPH-cytochrome P450 reductase (CPR) domain containing FAD and FMN cofactors in distinct domains of the CPR. A crystal structure of full-length BM3 enzyme is not available in its monomeric or catalytically active dimeric state. In this study, we provide detailed insights into the protein-protein interactions that occur between domains in the BM3 enzyme and characterize molecular interactions within the BM3 dimer by using several hybrid mass spectrometry (MS) techniques, namely native ion mobility MS (IM-MS), collision-induced unfolding (CIU), and hydrogen-deuterium exchange MS (HDX-MS). These methods enable us to probe the structure, stoichiometry, and domain interactions in the ∼240 kDa BM3 dimeric complex. We obtained high-sequence coverage (88–99%) in the HDX-MS experiments for full-length BM3 and its component domains in both the ligand-free and ligand-bound states. We identified important protein interaction sites, in addition to sites corresponding to heme-CPR domain interactions at the dimeric interface. These findings bring us closer to understanding the structure and catalytic mechanism of P450 BM3.
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Affiliation(s)
- Laura N Jeffreys
- The Manchester Institute of Biotechnology, School of Natural Sciences, Department of Chemistry, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom.,Manchester Synthetic Biology Research Centre for Fine and Speciality Chemicals (SYNBIOCHEM), The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Kamila J Pacholarz
- Michael Barber Centre for Collaborative Mass Spectrometry, Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Linus O Johannissen
- The Manchester Institute of Biotechnology, School of Natural Sciences, Department of Chemistry, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom.,Manchester Synthetic Biology Research Centre for Fine and Speciality Chemicals (SYNBIOCHEM), The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Hazel M Girvan
- The Manchester Institute of Biotechnology, School of Natural Sciences, Department of Chemistry, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom.,Manchester Synthetic Biology Research Centre for Fine and Speciality Chemicals (SYNBIOCHEM), The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Perdita E Barran
- The Manchester Institute of Biotechnology, School of Natural Sciences, Department of Chemistry, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom.,Manchester Synthetic Biology Research Centre for Fine and Speciality Chemicals (SYNBIOCHEM), The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom.,Michael Barber Centre for Collaborative Mass Spectrometry, Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Michael W Voice
- Cypex Ltd., 6 Tom McDonald Avenue, Dundee, DD2 1NH, United Kingdom
| | - Andrew W Munro
- The Manchester Institute of Biotechnology, School of Natural Sciences, Department of Chemistry, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom .,Manchester Synthetic Biology Research Centre for Fine and Speciality Chemicals (SYNBIOCHEM), The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
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20
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Abstract
The interactions between lipids and proteins are one of the most fundamental processes in living organisms, responsible for critical cellular events ranging from replication, cell division, signaling, and movement. Enabling the central coupling responsible for maintaining the functionality of the breadth of proteins, receptors, and enzymes that find their natural home in biological membranes, the fundamental mechanisms of recognition of protein for lipid, and vice versa, have been a focal point of biochemical and biophysical investigations for many decades. Complexes of lipids and proteins, such as the various lipoprotein factions, play central roles in the trafficking of important proteins, small molecules and metabolites and are often implicated in disease states. Recently an engineered lipoprotein particle, termed the nanodisc, a modified form of the human high density lipoprotein fraction, has served as a membrane mimetic for the investigation of membrane proteins and studies of lipid-protein interactions. In this review, we summarize the current knowledge regarding this self-assembling lipid-protein complex and provide examples for its utility in the investigation of a large number of biological systems.
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21
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Redhair M, Hackett JC, Pelletier RD, Atkins WM. Dynamics and Location of the Allosteric Midazolam Site in Cytochrome P4503A4 in Lipid Nanodiscs. Biochemistry 2020; 59:766-779. [PMID: 31961139 DOI: 10.1021/acs.biochem.9b01001] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Promiscuous and allosteric drug interactions with cytochrome P450 3A4 (CYP3A4) are ubiquitous but incompletely understood at the molecular level. A classic allosteric CYP3A4 drug interaction includes the benzodiazepine midazolam (MDZ). MDZ exhibits homotropic and heterotropic allostery when metabolized to 1'-hydroxy and 4-hydroxy metabolites in varying ratios. The combination of hydrogen-deuterium exchange mass spectrometry (HDX-MS) and Gaussian accelerated molecular dynamics (GaMD) simulations of CYP3A4 in lipid nanodiscs and in a lipid bilayer, respectively, reveals MDZ-dependent changes in dynamics in a membrane environment. The F-, G-, and intervening helices, as well as the loop preceding the β1-sheets, display the largest observed changes in HDX. The GaMD suggests a potential allosteric binding site for MDZ in the F'- and G'-regions, which undergo significant increases in HDX at near-saturating MDZ concentrations. The HDX-MS and GaMD results confirm that changes in dynamics are most significant near the developing consensus allosteric site, and these changes are distinct from those observed previously with the nonallosteric inhibitor ketoconazole. The results suggest that the allosteric MDZ remains mobile in its binding site at the Phe-cluster. The results further suggest that this binding site remains dynamic or changes the depth of insertion in the membrane.
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Affiliation(s)
- Michelle Redhair
- Department of Medicinal Chemistry , University of Washington , Seattle , Washington 98195-7610 , United States
| | - John C Hackett
- Department of Physiology and Biophysics and the Massey Cancer Center, School of Medicine , Virginia Commonwealth University , Richmond , Virginia 23298-0035 , United States
| | - Robert D Pelletier
- Department of Medicinal Chemistry , University of Washington , Seattle , Washington 98195-7610 , United States
| | - William M Atkins
- Department of Medicinal Chemistry , University of Washington , Seattle , Washington 98195-7610 , United States
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22
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Ying B, Zhong Y, Wang J. Impact of peripheral mutations on the access channels of human cytochrome P450 1A2. J Biomol Struct Dyn 2019; 38:4906-4913. [PMID: 31658882 DOI: 10.1080/07391102.2019.1686425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Beili Ying
- School of Life Sciences, Fudan University, Shanghai, China.,Shanghai Center for Bioinformation Technology, Shanghai, China
| | - Yang Zhong
- School of Life Sciences, Fudan University, Shanghai, China
| | - Jingfang Wang
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China
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23
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Revin VV, Pinyaev SI, Parchaykina MV, Revina ES, Maksimov GV, Kuzmenko TP. The Effect of Resveratrol on the Composition and State of Lipids and the Activity of Phospholipase A 2 During the Excitation and Regeneration of Somatic Nerves. Front Physiol 2019; 10:384. [PMID: 31057413 PMCID: PMC6482430 DOI: 10.3389/fphys.2019.00384] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 03/21/2019] [Indexed: 12/27/2022] Open
Abstract
It has been shown that in the somatic nerve's lipids, both during excitation and transection, changes occur with the composition of individual phospholipids and in phospholipids fatty acids, which changes the phase state of the myelin and nerve fiber axolemma lipid bilayer. A main contribution in the nerve degenerative processes is dependent on the composition phospholipid's fatty acid changes during the activation of both Ca2+-dependent and Ca2+-independent phospholipase A2 forms. At the same time, we studded changes in phosphoinisitol (PI) and diacylglycerol (DAG), which depend on the phosphoinositide cycle function during nerve excitation and degeneration processes. It was found that myelin lipids and nerve fiber axolemmas are involved not only in the functioning of the peripheral nerves, but also the pathological processes underlying deep functional and structural disorders. The effect of resveratrol on regeneration processes in the damaged rat sciatic nerve has also been investigated.
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Affiliation(s)
- Victor Vasilevich Revin
- Department of Biotechnology, Bioengineering and Biochemistry, National Research Ogarev Mordovia State University, Saransk, Russia
| | - Sergey Ivanovich Pinyaev
- Department of Biotechnology, Bioengineering and Biochemistry, National Research Ogarev Mordovia State University, Saransk, Russia
| | - Marina Vladimirovna Parchaykina
- Department of Biotechnology, Bioengineering and Biochemistry, National Research Ogarev Mordovia State University, Saransk, Russia
| | - Elvira Sergeevna Revina
- Department of Biotechnology, Bioengineering and Biochemistry, National Research Ogarev Mordovia State University, Saransk, Russia
| | | | - Tatyana Pavlovna Kuzmenko
- Department of Biotechnology, Bioengineering and Biochemistry, National Research Ogarev Mordovia State University, Saransk, Russia
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24
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Hydrogen-deuterium exchange mass spectrometry of membrane proteins in lipid nanodiscs. Chem Phys Lipids 2019; 220:14-22. [PMID: 30802434 DOI: 10.1016/j.chemphyslip.2019.02.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 02/20/2019] [Accepted: 02/21/2019] [Indexed: 12/31/2022]
Abstract
Hydrogen deuterium exchange mass spectrometry (H/DX MS) provides a quantitative comparison of the relative rates of exchange of amide protons for solvent deuterons. In turn, the rate of amide exchange depends on a complex combination of the stability of local secondary structure, solvent accessibility, and dynamics. H/DX MS has, therefore, been widely used to probe structure and function of soluble proteins, but its application to membrane proteins was limited previously to detergent solubilized samples. The large excess of lipids from model membranes, or from membrane fractions derived from in vivo samples, presents challenges with mass spectrometry. The lipid nanodisc platform, consisting of apolipoprotein A-derived membrane scaffold proteins, provides a native like membrane environment in which to capture analyte membrane proteins with a well defined, and low, ratio of lipid to protein. Membrane proteins in lipid nanodiscs are amenable to H/DX MS, and this is expected to lead to a rapid increase in the number of membrane proteins subjected to this analysis. Here we review the few literature examples of the application of H/DX MS to membrane proteins in nanodiscs. The incremental improvements in the experimental workflow of the H/DX MS are described and potential applications of this approach to study membrane proteins are described.
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25
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Camp T, McLean M, Kato M, Cheruzel L, Sligar S. The hydrodynamic motion of Nanodiscs. Chem Phys Lipids 2019; 220:28-35. [PMID: 30802435 DOI: 10.1016/j.chemphyslip.2019.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 02/20/2019] [Accepted: 02/21/2019] [Indexed: 02/02/2023]
Abstract
We present a fluorescence-based methodology for monitoring the rotational dynamics of Nanodiscs. Nanodiscs are nano-scale lipid bilayers surrounded by a helical membrane scaffold protein (MSP) that have found considerable use in studying the interactions between membrane proteins and their lipid bilayer environment. Using a long-lifetime Ruthenium label covalently attached to the Nanodiscs, we find that Nanodiscs of increasing diameter, made by varying the number of helical repeats in the MSP, display increasing rotational correlation times. We also model our system using both analytical equations that describe rotating spheroids and numerical calculations performed on atomic models of Nanodiscs. Using these methods, we observe a linear relationship between the experimentally determined rotational correlation times and those calculated from both analytical equations and numerical solutions. This work sets the stage for accurate, label-free quantification of protein-lipid interactions at the membrane surface.
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Affiliation(s)
- Tyler Camp
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, 314F Roger Adams Laboratory (MC-712), 600 S Mathews Ave, Urbana, IL, 61801, United States; Department of Biochemistry, University of Illinois at Urbana-Champaign, 417 RAL (MC-712), 600 South Mathews Avenue, Urbana, IL, 61801, United States
| | - Mark McLean
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 417 RAL (MC-712), 600 South Mathews Avenue, Urbana, IL, 61801, United States
| | - Mallory Kato
- Department of Chemistry, San Jose State University, San Jose, CA, 95192-0101, United States
| | - Lionel Cheruzel
- Department of Chemistry, San Jose State University, San Jose, CA, 95192-0101, United States
| | - Stephen Sligar
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, 314F Roger Adams Laboratory (MC-712), 600 S Mathews Ave, Urbana, IL, 61801, United States; Department of Biochemistry, University of Illinois at Urbana-Champaign, 417 RAL (MC-712), 600 South Mathews Avenue, Urbana, IL, 61801, United States.
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26
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Benhaim M, Lee KK, Guttman M. Tracking Higher Order Protein Structure by Hydrogen-Deuterium Exchange Mass Spectrometry. Protein Pept Lett 2019; 26:16-26. [PMID: 30543159 PMCID: PMC6386625 DOI: 10.2174/0929866526666181212165037] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 08/30/2018] [Accepted: 11/17/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND Structural biology has provided a fundamental understanding of protein structure and mechanistic insight into their function. However, high-resolution structures alone are insufficient for a complete understanding of protein behavior. Higher energy conformations, conformational changes, and subtle structural fluctuations that underlie the proper function of proteins are often difficult to probe using traditional structural approaches. Hydrogen/Deuterium Exchange with Mass Spectrometry (HDX-MS) provides a way to probe the accessibility of backbone amide protons under native conditions, which reports on local structural dynamics of solution protein structure that can be used to track complex structural rearrangements that occur in the course of a protein's function. CONCLUSION In the last 20 years the advances in labeling techniques, sample preparation, instrumentation, and data analysis have enabled HDX to gain insights into very complex biological systems. Analysis of challenging targets such as membrane protein complexes is now feasible and the field is paving the way to the analysis of more and more complex systems.
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Affiliation(s)
- Mark Benhaim
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195 USA
| | - Kelly K. Lee
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195 USA
| | - Miklos Guttman
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195 USA
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27
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Barnaba C, Ramamoorthy A. Picturing the Membrane-assisted Choreography of Cytochrome P450 with Lipid Nanodiscs. Chemphyschem 2018; 19:2603-2613. [DOI: 10.1002/cphc.201800444] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Indexed: 01/08/2023]
Affiliation(s)
- Carlo Barnaba
- Biophysics and Department of Chemistry; University of Michigan; Ann Arbor, MI 48109-1055 USA
| | - Ayyalusamy Ramamoorthy
- Biophysics and Department of Chemistry; University of Michigan; Ann Arbor, MI 48109-1055 USA
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28
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Ravula T, Barnaba C, Mahajan M, Anantharamaiah GM, Im SC, Waskell L, Ramamoorthy A. Membrane environment drives cytochrome P450's spin transition and its interaction with cytochrome b 5. Chem Commun (Camb) 2018; 53:12798-12801. [PMID: 29143058 DOI: 10.1039/c7cc07520k] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Heme's spin-multiplicity is key in determining the enzymatic function of cytochrome P450 (cytP450). The origin of the low-spin state in ferric P450 is still under debate. Here, we report the first experimental demonstration of P450's membrane interaction altering its spin equilibrium which is accompanied by a stronger affinity for cytochrome b5. These results highlight the importance of lipid membrane for the function of P450.
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Affiliation(s)
- Thirupathi Ravula
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA.
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29
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Hackett JC. Membrane-embedded substrate recognition by cytochrome P450 3A4. J Biol Chem 2018; 293:4037-4046. [PMID: 29382727 DOI: 10.1074/jbc.ra117.000961] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/26/2018] [Indexed: 12/15/2022] Open
Abstract
Cytochrome P450 3A4 (CYP3A4) is the dominant xenobiotic-metabolizing enzyme in the liver and intestine and is involved in the disposition of more than 50% of drugs. Because of its ability to bind multiple substrates, its reaction kinetics are complex, and its association with the microsomal membrane confounds our understanding of how this enzyme recognizes and recruits diverse substrates. Testosterone (TST) hydroxylation is the prototypical CYP3A4 reaction, displaying positive homotropic cooperativity with three binding sites. Here, exploiting the capability of accelerated molecular dynamics (aMD) to sample events in the millisecond regime, I performed >25-μs aMD simulations in the presence of three TST molecules. These simulations identified high-occupancy surface-binding sites as well as a pathway for TST ingress into the CYP3A4 active site originating in the membrane. Adaptive biasing force analysis of the latter pathway revealed a metastable intermediate that could constitute a third binding site at high TST concentrations. Prompted by the observation that interactions between TST and the G'-helix mobilize the ligand into the active site, a free-energy analysis of TST distribution in the membrane was conducted and revealed that the depth of the G'-helix is optimal for extracting TST. In summary, these simulations confirm separate, but adjacent substrate-binding sites within the enzyme and the existence of an auxiliary TST-binding site. The broader impact of these simulations is that they support a mechanism in which cytochromes P450 directly recruit membrane-solubilized substrates.
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Affiliation(s)
- John C Hackett
- From the Department of Physiology and Biophysics and the Massey Cancer Center, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298-0035
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30
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Barnaba C, Taylor E, Brozik JA. Dissociation Constants of Cytochrome P450 2C9/Cytochrome P450 Reductase Complexes in a Lipid Bilayer Membrane Depend on NADPH: A Single-Protein Tracking Study. J Am Chem Soc 2017; 139:17923-17934. [PMID: 29148818 DOI: 10.1021/jacs.7b08750] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cytochrome P450-reductase (CPR) is a versatile NADPH-dependent electron donor located in the cytoplasmic side of the endoplasmic reticulum. It is an electron transferase that is able to deliver electrons to a variety of membrane-bound oxidative partners, including the drug-metabolizing enzymes of the cytochrome P450s (P450). CPR is also stoichiometrically limited compared to its oxidative counterparts, and hypotheses have arisen about possible models that can overcome the stoichiometric imbalance, including quaternary organization of P450 and diffusion-limited models. Described here are results from a single-protein tracking study of fluorescently labeled CPR and cytochrome P450 2C9 (CYP2C9) molecules in which stochastic analysis was used to determine the dissociation constants of CPR/CYP2C9 complexes in a lipid bilayer membrane for the first time. Single-protein trajectories demonstrate the transient nature of these CPR-CYP2C9 interactions, and the measured Kd values are highly dependent on the redox state of CPR. It is shown that CPRox/CYP2C9 complexes have a much higher dissociation constant than CPR2-/CYP2C9 or CPR4-/CYP2C9 complexes, and a model is presented to account for these results. An Arrhenius analysis of diffusion constants was also carried out, demonstrating that the reduced forms of CPR and CYP2C9 interact differently with the biomimetic ER and may, in addition to protein conformational changes, contribute to the observed NADPH-dependent shift in Kd. Finally, it is also shown that the CPRox/CYP2C9 affinity depends on the nature of the ligand, being higher when a substrate is bound, compared to an inhibitor.
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Affiliation(s)
- Carlo Barnaba
- Department of Chemistry, Washington State University , P.O. Box 644630, Pullman, Washington 99164-4630, United States
| | - Evan Taylor
- Department of Chemistry, Washington State University , P.O. Box 644630, Pullman, Washington 99164-4630, United States
| | - James A Brozik
- Department of Chemistry, Washington State University , P.O. Box 644630, Pullman, Washington 99164-4630, United States
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31
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Hsu MH, Savas U, Johnson EF. The X-Ray Crystal Structure of the Human Mono-Oxygenase Cytochrome P450 3A5-Ritonavir Complex Reveals Active Site Differences between P450s 3A4 and 3A5. Mol Pharmacol 2017; 93:14-24. [PMID: 29093019 DOI: 10.1124/mol.117.109744] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 10/25/2017] [Indexed: 01/01/2023] Open
Abstract
The contributions of cytochrome P450 3A5 to the metabolic clearance of marketed drugs is unclear, but its probable role is to augment the metabolism of several drugs that are largely cleared by P450 3A4. Selective metabolism by 3A4 is often a concern in drug development owing to potential drug-drug interactions and the variability of 3A4 and 3A5 expression. The contribution of P450 3A5 to these clearance pathways varies between individuals owing to genetic differences and similarities and differences in the metabolic properties of 3A5 compared with 3A4. To better understand the structural differences between P450s 3A4 and 3A5, the structure of 3A5 complexed with ritonavir was determined by X-ray crystallography to a limiting resolution of 2.91 Å. The secondary and tertiary structures of 3A5 and 3A4 are similar, but the architectures of their active sites differ. The 3A5 active site is taller and narrower than that of 3A4. As a result, ritonavir adopts a distinctly different conformation to fit into the cavity of 3A5 than seen for 3A4. These structural changes reflect amino acid differences that alter the conformation of the helix F through helix G region in the upper portion of the cavity and ionic interactions between residues in the beta-sheet domain that reduce the width of the cavity. The structural differences exhibited by 3A4 and 3A5 suggest that the overlap of catalytic activities may reflect molecular flexibility that determines how alternative conformers fit into the different active site architectures of the two enzymes.
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Affiliation(s)
- Mei-Hui Hsu
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California
| | - Uzen Savas
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California
| | - Eric F Johnson
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California
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32
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Lipid-Mediated Regulation of Embedded Receptor Kinases via Parallel Allosteric Relays. Biophys J 2017; 112:643-654. [PMID: 28256224 DOI: 10.1016/j.bpj.2016.12.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/15/2016] [Accepted: 12/12/2016] [Indexed: 01/29/2023] Open
Abstract
Membrane-anchored receptors are essential cellular signaling elements for stimulus sensing, propagation, and transmission inside cells. However, the contributions of lipid interactions to the function and dynamics of embedded receptor kinases have not been described in detail. In this study, we used amide hydrogen/deuterium exchange mass spectrometry, a sensitive biophysical approach, to probe the dynamics of a membrane-embedded receptor kinase, EnvZ, together with functional assays to describe the role of lipids in receptor kinase function. Our results reveal that lipids play an important role in regulating receptor function through interactions with transmembrane segments, as well as through peripheral interactions with nonembedded domains. Specifically, the lipid membrane allosterically modulates the activity of the embedded kinase by altering the dynamics of a glycine-rich motif that is critical for phosphotransfer from ATP. This allostery in EnvZ is independent of membrane composition and involves direct interactions with transmembrane and periplasmic segments, as well as peripheral interactions with nonembedded domains of the protein. In the absence of the membrane-spanning regions, lipid allostery is propagated entirely through peripheral interactions. Whereas lipid allostery impacts the phosphotransferase function of the kinase, extracellular stimulus recognition is mediated via a four-helix bundle subdomain located in the cytoplasm, which functions as the osmosensing core through osmolality-dependent helical stabilization. Our findings emphasize the functional modularity in a membrane-embedded kinase, separated into membrane association, phosphotransferase function, and stimulus recognition. These components are integrated through long-range communication relays, with lipids playing an essential role in regulation.
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33
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Sevrioukova IF. High-Level Production and Properties of the Cysteine-Depleted Cytochrome P450 3A4. Biochemistry 2017; 56:3058-3067. [PMID: 28590129 DOI: 10.1021/acs.biochem.7b00334] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Human drug-metabolizing cytochrome P450 3A4 (CYP3A4) is a dynamic enzyme with a large and highly malleable active site that can fit structurally diverse compounds. Despite extensive investigations, structure-function relationships and conformational dynamics in CYP3A4 are not fully understood. This study was undertaken to engineer a well-expressed and functionally active cysteine-depleted CYP3A4 that can be used in biochemical and biophysical studies. cDNA codon optimization and screening mutagenesis were utilized to boost the level of bacterial expression of CYP3A4 and identify the least harmful substitutions for all six non-heme-ligating cysteines. The C58A/C64M/C98A/C239T/C377A/C468S (Cys-less) mutant was found to be expressed as highly as the optimized wild-type (opt-WT) CYP3A4. The high-resolution X-ray structures of opt-WT and Cys-less CYP3A4 revealed that gene optimization leads to a different folding in the Phe108 and Phe189 regions and promotes binding of the active site glycerol that interlocks Ser119 and Arg212, critical for ligand association, and the hydrophobic cluster adjacent to Phe108. Crowding and decreased flexibility of the active site, as well as structural alterations observed at the C64M, C239T, and C468S mutational sites, might be responsible for the distinct ligand binding behavior of opt-WT and Cys-less CYP3A4. Nonetheless, the Cys-less mutant could be used for structure-function investigations because it orients bromoergocryptine and ritonavir (a high-affinity substrate and a high-potency inhibitor, respectively) like the WT and has a higher activity toward 7-benzyloxy(4-trifluoromethyl)coumarin.
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Affiliation(s)
- Irina F Sevrioukova
- Department of Molecular Biology and Biochemistry, University of California , Irvine, California 92697-3900, United States
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34
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Barnaba C, Gentry K, Sumangala N, Ramamoorthy A. The catalytic function of cytochrome P450 is entwined with its membrane-bound nature. F1000Res 2017; 6:662. [PMID: 28529725 PMCID: PMC5428493 DOI: 10.12688/f1000research.11015.1] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/04/2017] [Indexed: 12/21/2022] Open
Abstract
Cytochrome P450, a family of monooxygenase enzymes, is organized as a catalytic metabolon, which requires enzymatic partners as well as environmental factors that tune its complex dynamic. P450 and its reducing counterparts—cytochrome P450-reductase and cytochrome
b
5—are membrane-bound proteins located in the cytosolic side of the endoplasmic reticulum. They are believed to dynamically associate to form functional complexes. Increasing experimental evidence signifies the role(s) played by both protein-protein and protein-lipid interactions in P450 catalytic function and efficiency. However, the biophysical challenges posed by their membrane-bound nature have severely limited high-resolution understanding of the molecular interfaces of these interactions. In this article, we provide an overview of the current knowledge on cytochrome P450, highlighting the environmental factors that are entwined with its metabolic function. Recent advances in structural biophysics are also discussed, setting up the bases for a new paradigm in the study of this important class of membrane-bound enzymes.
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Affiliation(s)
- Carlo Barnaba
- Biophysics Program and Department of Chemistry, The University of Michigan, Ann Arbor, MI, USA
| | - Katherine Gentry
- Biophysics Program and Department of Chemistry, The University of Michigan, Ann Arbor, MI, USA
| | - Nirupama Sumangala
- Biophysics Program and Department of Chemistry, The University of Michigan, Ann Arbor, MI, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics Program and Department of Chemistry, The University of Michigan, Ann Arbor, MI, USA
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35
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Abstract
Membrane proteins play a most important part in metabolism, signaling, cell motility, transport, development, and many other biochemical and biophysical processes which constitute fundamentals of life on the molecular level. Detailed understanding of these processes is necessary for the progress of life sciences and biomedical applications. Nanodiscs provide a new and powerful tool for a broad spectrum of biochemical and biophysical studies of membrane proteins and are commonly acknowledged as an optimal membrane mimetic system that provides control over size, composition, and specific functional modifications on the nanometer scale. In this review we attempted to combine a comprehensive list of various applications of nanodisc technology with systematic analysis of the most attractive features of this system and advantages provided by nanodiscs for structural and mechanistic studies of membrane proteins.
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Affiliation(s)
- Ilia G Denisov
- Department of Biochemistry and Department of Chemistry, University of Illinois , Urbana, Illinois 61801, United States
| | - Stephen G Sligar
- Department of Biochemistry and Department of Chemistry, University of Illinois , Urbana, Illinois 61801, United States
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36
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Du H, Li J, Cai Y, Zhang H, Liu G, Tang Y, Li W. Computational Investigation of Ligand Binding to the Peripheral Site in CYP3A4: Conformational Dynamics and Inhibitor Discovery. J Chem Inf Model 2017; 57:616-626. [DOI: 10.1021/acs.jcim.7b00012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Hanwen Du
- Shanghai Key Laboratory of New Drug Design,
School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Junhao Li
- Shanghai Key Laboratory of New Drug Design,
School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Yingchun Cai
- Shanghai Key Laboratory of New Drug Design,
School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Hongxiao Zhang
- Shanghai Key Laboratory of New Drug Design,
School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Guixia Liu
- Shanghai Key Laboratory of New Drug Design,
School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Yun Tang
- Shanghai Key Laboratory of New Drug Design,
School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Weihua Li
- Shanghai Key Laboratory of New Drug Design,
School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
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37
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Conformational dynamics of a neurotransmitter:sodium symporter in a lipid bilayer. Proc Natl Acad Sci U S A 2017; 114:E1786-E1795. [PMID: 28223522 DOI: 10.1073/pnas.1613293114] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Neurotransmitter:sodium symporters (NSSs) are integral membrane proteins responsible for the sodium-dependent reuptake of small-molecule neurotransmitters from the synaptic cleft. The symporters for the biogenic amines serotonin (SERT), dopamine (DAT), and norepinephrine (NET) are targets of multiple psychoactive agents, and their dysfunction has been implicated in numerous neuropsychiatric ailments. LeuT, a thermostable eubacterial NSS homolog, has been exploited as a model protein for NSS members to canvass the conformational mechanism of transport with a combination of X-ray crystallography, cysteine accessibility, and solution spectroscopy. Despite yielding remarkable insights, these studies have primarily been conducted with protein in the detergent-solubilized state rather than embedded in a membrane mimic. In addition, solution spectroscopy has required site-specific labeling of nonnative cysteines, a labor-intensive process occasionally resulting in diminished transport and/or binding activity. Here, we overcome these limitations by reconstituting unlabeled LeuT in phospholipid bilayer nanodiscs, subjecting them to hydrogen-deuterium exchange coupled with mass spectrometry (HDX-MS), and facilitating interpretation of the data with molecular dynamics simulations. The data point to changes of accessibility and dynamics of structural elements previously implicated in the transport mechanism, in particular transmembrane helices (TMs) 1a and 7 as well as extracellular loops (ELs) 2 and 4. The results therefore illuminate the value of this strategy for interrogating the conformational mechanism of the more clinically significant mammalian membrane proteins including SERT and DAT, neither of which tolerates complete removal of endogenous cysteines, and whose activity is heavily influenced by neighboring lipids.
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38
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McClary WD, Sumida JP, Scian M, Paço L, Atkins WM. Membrane Fluidity Modulates Thermal Stability and Ligand Binding of Cytochrome P4503A4 in Lipid Nanodiscs. Biochemistry 2016; 55:6258-6268. [PMID: 27782404 DOI: 10.1021/acs.biochem.6b00715] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Cytochrome P4503A4 (CYP3A4) is a peripheral membrane protein that plays a major role in enzymatic detoxification of many drugs and toxins. CYP3A4 has an integral membrane N-terminal helix and a localized patch comprised of the G' and F' helix regions that are embedded in the membrane, but the effects of membrane composition on CYP3A4 function are unknown. Here, circular dichroism and differential scanning calorimetry were used to compare the stability of CYP3A4 in lipid bilayer nanodiscs with varying ratios of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine to 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). These lipids differ in the acyl-chain length and their degree of unsaturation. The thermal denaturation of CYP3A4 in nanodiscs occurs in a temperature range distinct from that of the nanodisc denaturation so it can be monitored calorimetrically. Melting temperatures (Tm), heat capacities (ΔCp), and calorimetric enthalpies (ΔHcal) for denaturation of CYP3A4 each increased with an increasing fraction of DMPC, with a maximum at 50% DMPC, before decreasing at 75% DMPC. Addition of the inhibitor ketoconazole results in increased thermal stability, and larger ΔCp and ΔHcal values, with different sensitivities to lipid composition. Effects of lipid composition on ligand binding dynamics were also studied. Equilibrium binding affinities of both ketoconazole (KTZ) and testosterone (TST) were minimally affected by lipid composition. However, stopped-flow analyses indicate that the rates of KTZ binding reach a maximum in membranes containing 50% DMPC, whereas the rate of TST binding decreases continuously with an increasing DMPC concentration. These results indicate that CYP3A4 is highly sensitive to the acyl-chain composition of the lipids and fluidity of the membrane in which it is embedded.
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Affiliation(s)
- Wynton D McClary
- Department of Medicinal Chemistry, University of Washington , Box 357610, Seattle, Washington 98195-7610, United States
| | - John P Sumida
- Department of Medicinal Chemistry, University of Washington , Box 357610, Seattle, Washington 98195-7610, United States
| | - Michele Scian
- Department of Medicinal Chemistry, University of Washington , Box 357610, Seattle, Washington 98195-7610, United States
| | - Lorela Paço
- Department of Medicinal Chemistry, University of Washington , Box 357610, Seattle, Washington 98195-7610, United States
| | - William M Atkins
- Department of Medicinal Chemistry, University of Washington , Box 357610, Seattle, Washington 98195-7610, United States
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39
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Lu Y, Zhang H, Niedzwiedzki DM, Jiang J, Blankenship RE, Gross ML. Fast Photochemical Oxidation of Proteins Maps the Topology of Intrinsic Membrane Proteins: Light-Harvesting Complex 2 in a Nanodisc. Anal Chem 2016; 88:8827-34. [PMID: 27500903 PMCID: PMC5201186 DOI: 10.1021/acs.analchem.6b01945] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Although membrane proteins are crucial participants in photosynthesis and other biological processes, many lack high-resolution structures. Prior to achieving a high-resolution structure, we are investigating whether MS-based footprinting can provide coarse-grained protein structure by following structural changes that occur upon ligand binding, pH change, and membrane binding. Our platform probes topology and conformation of membrane proteins by combining MS-based footprinting, specifically fast photochemical oxidation of proteins (FPOP), and lipid Nanodiscs, which are more similar to the native membrane environment than are the widely used detergent micelles. We describe here results that show a protein's outer membrane regions are more heavily footprinted by OH radicals whereas the regions spanning the lipid bilayer remain inert to the labeling. Nanodiscs generally exhibit more protection of membrane proteins compared to detergent micelles and less shielding to those protein residues that exist outside the membrane. The combination of immobilizing the protein in Nanodiscs and footprinting with FPOP is a feasible approach to map extra-membrane protein surfaces, even at the amino-acid level, and to illuminate intrinsic membrane protein topology.
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Affiliation(s)
- Yue Lu
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
- Photosynthetic Antenna Research Center, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Hao Zhang
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
- Photosynthetic Antenna Research Center, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Dariusz M. Niedzwiedzki
- Photosynthetic Antenna Research Center, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Jing Jiang
- Photosynthetic Antenna Research Center, Washington University in St. Louis, St. Louis, Missouri 63130, United States
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Robert E. Blankenship
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
- Photosynthetic Antenna Research Center, Washington University in St. Louis, St. Louis, Missouri 63130, United States
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
- Photosynthetic Antenna Research Center, Washington University in St. Louis, St. Louis, Missouri 63130, United States
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40
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Shah MB, Jang HH, Wilderman PR, Lee D, Li S, Zhang Q, Stout CD, Halpert JR. Effect of detergent binding on cytochrome P450 2B4 structure as analyzed by X-ray crystallography and deuterium-exchange mass spectrometry. Biophys Chem 2016; 216:1-8. [PMID: 27280734 DOI: 10.1016/j.bpc.2016.05.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 05/24/2016] [Indexed: 11/24/2022]
Abstract
Multiple crystal structures of CYP2B4 have demonstrated the binding of the detergent 5-cyclohexyl-1-pentyl-β-D-maltoside (CYMAL-5) in a peripheral pocket located adjacent to the active site. To explore the consequences of detergent binding, X-ray crystal structures of the peripheral pocket mutant CYP2B4 F202W were solved in the presence of hexaethylene glycol monooctyl ether (C8E6) and CYMAL-5. The structure in the presence of CYMAL-5 illustrated a closed conformation indistinguishable from the previously solved wild-type. In contrast, the F202W structure in the presence of C8E6 revealed a detergent molecule that coordinated the heme-iron and extended to the protein surface through the substrate access channel 2f. Despite the overall structural similarity of these detergent complexes, remarkable differences were observed in the A, A', and H helices, the F-G cassette, the C-D and β4 loop region. Hydrogen-deuterium exchange mass spectrometry (DXMS) was employed to probe these differences and to test the effect of detergents in solution. The presence of either detergent increased the H/D exchange rate across the plastic regions, and the results obtained by DXMS in solution were consistent in general with the relevant structural snapshots. The study provides insight into effect of detergent binding and the interpretation of associated conformational dynamics of CYP2B4.
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Affiliation(s)
- Manish B Shah
- School of Pharmacy, University of Connecticut, Storrs, CT 06269, United States.
| | - Hyun-Hee Jang
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - P Ross Wilderman
- School of Pharmacy, University of Connecticut, Storrs, CT 06269, United States
| | - David Lee
- The Department of Medicine, University of California, San Diego, La Jolla, CA 92093, United States
| | - Sheng Li
- The Department of Medicine, University of California, San Diego, La Jolla, CA 92093, United States
| | - Qinghai Zhang
- The Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, United States
| | - C David Stout
- The Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, United States
| | - James R Halpert
- School of Pharmacy, University of Connecticut, Storrs, CT 06269, United States
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