1
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Han SB, Teuffel J, Mukherjee G, Wade RC. Multiresolution molecular dynamics simulations reveal the interplay between conformational variability and functional interactions in membrane-bound cytochrome P450 2B4. Protein Sci 2024; 33:e5165. [PMID: 39291728 PMCID: PMC11409197 DOI: 10.1002/pro.5165] [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: 07/12/2024] [Accepted: 08/16/2024] [Indexed: 09/19/2024]
Abstract
Cytochrome P450 2B4 (CYP 2B4) is one of the best-characterized CYPs and serves as a key model system for understanding the mechanisms of microsomal class II CYPs, which metabolize most known drugs. The highly flexible nature of CYP 2B4 is apparent from crystal structures that show the active site with either a wide open or a closed heme binding cavity. Here, we investigated the conformational ensemble of the full-length CYP 2B4 in a phospholipid bilayer, using multiresolution molecular dynamics (MD) simulations. Coarse-grained MD simulations revealed two predominant orientations of CYP 2B4's globular domain with respect to the bilayer. Their refinement by atomistic resolution MD showed adaptation of the enzyme's interaction with the lipid bilayer, leading to open configurations that facilitate ligand access to the heme binding cavity. CAVER analysis of enzyme tunnels, AquaDuct analysis of water routes, and Random Acceleration Molecular Dynamics simulations of ligand dissociation support the conformation-dependent passage of molecules between the active site and the protein surroundings. Furthermore, simulation of the re-entry of the inhibitor bifonazole into the open conformation of CYP 2B4 resulted in binding at a transient hydrophobic pocket within the active site cavity that may play a role in substrate binding or allosteric regulation. Together, these results show how the open conformation of CYP 2B4 facilitates the binding of substrates from and release of products to the membrane, whereas the closed conformation prolongs the residence time of substrates or inhibitors and selectively allows the passage of smaller reactants via the solvent and water channels.
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Affiliation(s)
- Sungho Bosco Han
- Molecular and Cellular Modeling GroupHeidelberg Institute for Theoretical Studies (HITS)HeidelbergGermany
- Faculty of BiosciencesHeidelberg UniversityHeidelbergGermany
| | - Jonathan Teuffel
- Molecular and Cellular Modeling GroupHeidelberg Institute for Theoretical Studies (HITS)HeidelbergGermany
- Faculty of Engineering SciencesHeidelberg UniversityHeidelbergGermany
- Graduate School of Mathematical and Computational Methods for the Sciences (HGS MathComp)Heidelberg UniversityHeidelbergGermany
| | - Goutam Mukherjee
- Molecular and Cellular Modeling GroupHeidelberg Institute for Theoretical Studies (HITS)HeidelbergGermany
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ‐ZMBH AllianceHeidelberg UniversityHeidelbergGermany
| | - Rebecca C. Wade
- Molecular and Cellular Modeling GroupHeidelberg Institute for Theoretical Studies (HITS)HeidelbergGermany
- Faculty of BiosciencesHeidelberg UniversityHeidelbergGermany
- Faculty of Engineering SciencesHeidelberg UniversityHeidelbergGermany
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ‐ZMBH AllianceHeidelberg UniversityHeidelbergGermany
- Interdisciplinary Center for Scientific Computing (IWR)Heidelberg UniversityHeidelbergGermany
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2
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Krishnarjuna B, Sharma G, Im SC, Auchus R, Anantharamaiah GM, Ramamoorthy A. Characterization of nanodisc-forming peptides for membrane protein studies. J Colloid Interface Sci 2024; 653:1402-1414. [PMID: 37801850 PMCID: PMC10864042 DOI: 10.1016/j.jcis.2023.09.162] [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: 07/27/2023] [Revised: 09/11/2023] [Accepted: 09/27/2023] [Indexed: 10/08/2023]
Abstract
Lipid-bilayer nanodiscs provide a stable, native-like membrane environment for the functional and structural studies of membrane proteins and other membrane-binding molecules. Peptide-based nanodiscs having unique properties are developed for membrane protein studies and other biological applications. While the self-assembly process rendering the formation of peptide-nanodiscs is attractive, it is important to understand the stability and suitability of these nanodisc systems for membrane protein studies. In this study, we investigated the nanodiscs formation by the anti-inflammatory and tumor-suppressing peptide AEM28. AEM28 is a chimeric peptide containing a cationic-rich heparan sulfate proteoglycan- (HSPG)-binding domain from human apolipoprotein E (hapoE) (141-150) followed by the 18A peptide's amino acid sequence. AEM28-based nanodiscs made with different types of lipids were characterized using various biophysical techniques and compared with the nanodiscs formed using 2F or 4F peptides. Variable temperature dynamic light-scattering and 31P NMR experiments indicated the fusion and size heterogeneity of nanodiscs at high temperatures. The suitability of AEM28 and Ac-18A-NH2- (2F-) based nanodiscs for studying membrane proteins is demonstrated by reconstituting and characterizing a drug-metabolizing enzyme, cytochrome-P450 (CYP450), or the redox complex CYP450-CYP450 reductase. AEM28 and 2F were also tested for their efficacies in solubilizing E. coli membranes to understand the possibility of using them for detergent-free membrane protein isolation. Our experimental results suggest that AEM28 nanodiscs are suitable for studying membrane proteins with a net positive charge, whereas 2F-based nanodiscs are compatible with any membrane proteins and their complexes irrespective of their charge. Furthermore, both peptides solubilized E. coli cell membranes, indicating their use in membrane protein isolation and other applications related to membrane solubilization.
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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
| | - Gaurav Sharma
- Biophysics Program, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, University of Michigan, Arbor, MI 48109, USA
| | - Sang-Choul Im
- Department of Pharmacology and Internal Medicine, Division of Metabolism, Endocrinology, & Diabetes, University of Michigan, Ann Arbor, MI 48109, USA
| | - Richard Auchus
- Department of Pharmacology and Internal Medicine, Division of Metabolism, Endocrinology, & Diabetes, University of Michigan, Ann Arbor, MI 48109, USA
| | - G M Anantharamaiah
- Department of Medicine, University of Alabama at Birmingham Medical Center, Birmingham, AL 35294, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics Program, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, University of Michigan, Arbor, MI 48109, USA; National High Magnetic Field Laboratory, Department of Chemical and Biomedical Engineering, Tallahassee, FL 32310, USA.
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3
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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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4
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Yu S, Li M, Gao S, Zhou J. Engineering Saccharomyces cerevisiae for the production of dihydroquercetin from naringenin. Microb Cell Fact 2022; 21:213. [PMID: 36243863 PMCID: PMC9569186 DOI: 10.1186/s12934-022-01937-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 09/19/2022] [Indexed: 11/12/2022] Open
Abstract
Background Dihydroquercetin (DHQ), a powerful bioflavonoid, has a number of health-promoting qualities and shows potential as a treatment for a number of disorders. Dihydroquercetin biosynthesis is a promising solution to meet the rising demand for dihydroquercetin. However, due to the significant accumulation of eriodietyol (ERI), naringenin (NAR), dihydrokaempferol (DHK), and other metabolites, the yield of DHQ biosynthesis is low. As a result, this is the hindrance to the biosynthesis of DHQ. Results In this study, we proposed several strategies to enhance the product formation and reduce the metabolites in accumulation. The flavonoid 3′-hydroxylase (F3′H) and cytochrome P450 reductase from different species were co-expressed in S. cerevisiae, and the best strain expressing the P450-reductase enzyme complex (SmF3′H/ScCPR) yielded 435.7 ± 7.6 mg/L of ERI from NAR in the deepwell microplate. The product conversion rate was improved further by mutating the predicted potential ubiquitination sites to improve SmF3′H stability, resulting in a 12.8% increase in titre using the mutant SmF3′H (K290R). Besides, different F3Hs from various sources and promoters were tested for the improved DHQ production, with the best strain producing 381.2 ± 10.7 mg/L of DHQ from 1 g/L of NAR, suggesting the temporal regulation the expression of F3H is important for maximization the function of F3′H and F3H. Conclusion This study offers effective strategies for improving DHQ production from NAR and could be used as a reference for related research. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01937-8.
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Affiliation(s)
- Shiqin Yu
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,Engineering Research Center of Ministry of Education On Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | - Mingjia Li
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,Engineering Research Center of Ministry of Education On Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.,Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China
| | | | - Jingwen Zhou
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China. .,Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China. .,Engineering Research Center of Ministry of Education On Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China. .,Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, China.
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5
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Shen J, Wu G, Tsai AL, Zhou M. Transmembrane helices mediate the formation of a stable ternary complex of b 5R, cyt b 5, and SCD1. Commun Biol 2022; 5:956. [PMID: 36097052 PMCID: PMC9468158 DOI: 10.1038/s42003-022-03882-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 08/23/2022] [Indexed: 11/24/2022] Open
Abstract
Mammalian cytochrome b5 (cyt b5) and cytochrome b5 reductase (b5R) are electron carrier proteins for membrane-embedded oxidoreductases. Both b5R and cyt b5 have a cytosolic domain and a single transmembrane (TM) helix. The cytosolic domains of b5R and cyt b5 contain cofactors required for electron transfer, but it is not clear if the TM helix has function beyond being an anchor to the membrane. Here we show that b5R and cyt b5 form a stable binary complex, and so do cyt b5 and stearoyl-CoA desaturase-1 (SCD1). We also show that b5R, cyt b5 and SCD1 form a stable ternary complex. We demonstrate that the TM helices are required for the assembly of stable binary and ternary complexes where electron transfer rates are greatly enhanced. These results reveal a role of the TM helix in cyt b5 and b5R, and suggest that an electron transport chain composed of a stable ternary complex may be a general feature in membrane-embedded oxidoreductases that require cyt b5 and b5R. The transmembrane domains of mammalian cytochrome b5 (cyt b5), cyt b5 reductase (b5R), and stearoyl-CoA desaturase-1 (SCD1) form stable binary complexes between cyt b5/b5R or cyt b5/SCD1 and a ternary complex, which enhance electron transfer rates.
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Affiliation(s)
- Jiemin Shen
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Gang Wu
- Division of Hematology-Oncology, University of Texas McGovern Medical School, Houston, TX, 77030, USA
| | - Ah-Lim Tsai
- Division of Hematology-Oncology, University of Texas McGovern Medical School, Houston, TX, 77030, USA
| | - Ming Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
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6
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Krishnarjuna B, Im SC, Ravula T, Marte J, Auchus RJ, Ramamoorthy A. Non-Ionic Inulin-Based Polymer Nanodiscs Enable Functional Reconstitution of a Redox Complex Composed of Oppositely Charged CYP450 and CPR in a Lipid Bilayer Membrane. Anal Chem 2022; 94:11908-11915. [PMID: 35977417 PMCID: PMC10851674 DOI: 10.1021/acs.analchem.2c02489] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Although polymer-based lipid nanodiscs are increasingly used in the structural studies of membrane proteins, the charge of the belt-forming polymer is a major limitation for functional reconstitution of membrane proteins possessing an opposite net charge to that of the polymer. This limitation also rules out the reconstitution of a protein-protein complex composed of oppositely charged membrane proteins. In this study, we report the first successful functional reconstitution of a membrane-bound redox complex constituting a cationic cytochrome P450 (CYP450) and an anionic cytochrome P450 reductase (CPR) in non-ionic inulin-based lipid nanodiscs. The gel-to-liquid-crystalline phase-transition temperature (Tm) of DMPC:DMPG (7:3 w/w) lipids in polymer nanodiscs was determined by differential scanning calorimetry (DSC) and 31P NMR experiments. The CYP450-CPR redox complex reconstitution in polymer nanodiscs was characterized by size-exclusion chromatography (SEC), and the electron transfer kinetics was carried out using the stopped-flow technique under anaerobic conditions. The Tm of DMPC:DMPG (7:3 w/w) in polymer nanodiscs measured from 31P NMR agrees with that obtained from DSC and was found to be higher than that for liposomes due to the decreased cooperativity of lipids present in the nanodiscs. The stopped-flow measurements revealed the CYP450-CPR redox complex reconstituted in nanodiscs to be functional, and the electron transfer kinetics was found to be temperature-dependent. Based on the successful demonstration of the use of non-ionic inulin-based polymer nanodiscs reported in this study, we expect them to be useful in studying the function and structures of a variety of membrane proteins/complexes irrespective of the charge of the molecular components. Since the polymer nanodiscs were shown to align in an externally applied magnetic field, they can also be used to measure residual dipolar couplings (RDCs) and residual quadrupolar couplings (RQCs) for various molecules ranging from small molecules to soluble proteins and nucleic acids.
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Affiliation(s)
- Bankala Krishnarjuna
- Biophysics Program, Department of Chemistry, Macromolecular Science and Engineering, Biomedical Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Sang-Choul Im
- Department of Pharmacology and Internal Medicine, Division of Metabolism, Endocrinology, & Diabetes, University of Michigan, Ann Arbor, MI 48109
| | - Thirupathi Ravula
- Biophysics Program, Department of Chemistry, Macromolecular Science and Engineering, Biomedical Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Joseph Marte
- Biophysics Program, Department of Chemistry, Macromolecular Science and Engineering, Biomedical Engineering, Michigan Neuroscience Institute, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Richard J. Auchus
- Department of Pharmacology and Internal Medicine, Division of Metabolism, Endocrinology, & Diabetes, University of Michigan, Ann Arbor, MI 48109
| | - 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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7
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Abstract
Membrane proteins (MPs) play essential roles in numerous cellular processes. Because around 70% of the currently marketed drugs target MPs, a detailed understanding of their structure, binding properties, and functional dynamics in a physiologically relevant environment is crucial for a more detailed understanding of this important protein class. We here summarize the benefits of using lipid nanodiscs for NMR structural investigations and provide a detailed overview of the currently used lipid nanodisc systems as well as their applications in solution-state NMR. Despite the increasing use of other structural methods for the structure determination of MPs in lipid nanodiscs, solution NMR turns out to be a versatile tool to probe a wide range of MP features, ranging from the structure determination of small to medium-sized MPs to probing ligand and partner protein binding as well as functionally relevant dynamical signatures in a lipid nanodisc setting. We will expand on these topics by discussing recent NMR studies with lipid nanodiscs and work out a key workflow for optimizing the nanodisc incorporation of an MP for subsequent NMR investigations. With this, we hope to provide a comprehensive background to enable an informed assessment of the applicability of lipid nanodiscs for NMR studies of a particular MP of interest.
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Affiliation(s)
- Umut Günsel
- Bavarian NMR Center (BNMRZ) at the Department of Chemistry, Technical University of Munich, Ernst-Otto-Fischer-Strasse 2, 85748 Garching, Germany
| | - Franz Hagn
- Bavarian NMR Center (BNMRZ) at the Department of Chemistry, Technical University of Munich, Ernst-Otto-Fischer-Strasse 2, 85748 Garching, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
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8
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Sun SC, Huang HW, Lo YT, Chuang MC, Hsu YHH. Unraveling cardiolipin-induced conformational change of cytochrome c through H/D exchange mass spectrometry and quartz crystal microbalance. Sci Rep 2021; 11:1090. [PMID: 33441668 PMCID: PMC7806790 DOI: 10.1038/s41598-020-79905-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 12/04/2020] [Indexed: 11/21/2022] Open
Abstract
Cardiolipin (CL), a crucial component in inner mitochondrial membranes, interacts with cytochrome c (cyt c) to form a peroxidase complex for the catalysis of CL oxidation. Such interaction is pivotal to the mitochondrial regulation of apoptosis and is affected by the redox state of cyt c. In the present study, the redox-dependent interaction of cyt c with CL was investigated through amide hydrogen/deuterium exchange coupled with mass spectrometry (HDXMS) and quartz crystal microbalance with dissipation monitoring (QCM-D). Ferrous cyt c exhibited a more compact conformation compared with its ferric form, which was supported by the lower number of deuterons accumulated and the greater amplitude reduction on dissipation. Upon association with CL, ferrous cyt c resulted in a moderate increase in deuteration, whereas the ferric form caused a drastic increase of deuteration, which indicated that CL-bound ferric cyt c formed an extended conformation. These results were consistent with those of the frequency (f) − dissipation (D) experiments, which revealed that ferric cyt c yielded greater values of |ΔD/Δf| within the first minute. Further fragmentation analysis based on HDXMS indicated that the effect of CL binding was considerably different on ferric and ferrous cyt c in the C-helix and the Loop 9–24. In ferric cyt c, CL binding affected Met80 and destabilized His18 interaction with heme, which was not observed with ferrous cyt c. An interaction model was proposed to explain the aforementioned results.
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Affiliation(s)
- Sin-Cih Sun
- Department of Chemistry, Tunghai University, Taichung, Taiwan
| | - Hung-Wei Huang
- Department of Chemistry, Tunghai University, Taichung, Taiwan
| | - Yi-Ting Lo
- Department of Chemistry, Tunghai University, Taichung, Taiwan
| | - Min-Chieh Chuang
- Department of Chemistry, Tunghai University, Taichung, Taiwan. .,Department of Environmental Science and Engineering, Taichung, Taiwan.
| | - Yuan-Hao Howard Hsu
- Department of Chemistry, Tunghai University, Taichung, Taiwan. .,Biological Science Center, Tunghai University, Taichung, Taiwan.
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9
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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: 74] [Impact Index Per Article: 18.5] [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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10
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Bai J, Wang J, Ravula T, Im SC, Anantharamaiah GM, Waskell L, Ramamoorthy A. Expression, purification, and functional reconstitution of 19F-labeled cytochrome b5 in peptide nanodiscs for NMR studies. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2020; 1862:183194. [PMID: 31953231 PMCID: PMC7050362 DOI: 10.1016/j.bbamem.2020.183194] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 01/06/2020] [Accepted: 01/10/2020] [Indexed: 02/07/2023]
Abstract
Microsomal cytochrome b5 (cytb5) is a membrane-bound protein capable of donating the second electron to cytochrome P450s (cytP450s) in the cytP450s monooxygenase reactions. Recent studies have demonstrated the importance of the transmembrane domain of cytb5 in the interaction with cytP450 by stabilizing its monomeric structure. While recent NMR studies have provided high-resolution insights into the structural interactions between the soluble domains of ~16-kDa cytb5 and ~57-kDa cytP450 in a membrane environment, there is need for studies to probe the residues in the transmembrane region as well as to obtain intermolecular distance constraints to better understand the very large size cytb5-cytP450 complex structure in a near native membrane environment. In this study, we report the expression, purification, functional reconstitution of 19F-labeled full-length rabbit cytb5 in peptide based nanodiscs for structural studies using NMR spectroscopy. Size exclusion chromatography, dynamic light scattering, transmission electron microscopy, and NMR experiments show a stable reconstitution of cytb5 in 4F peptide-based lipid-nanodiscs. The reported results demonstrate the use of 19F NMR experiments to study 19F-labeled (with 5-fluorotryptophan (5FW)) cytb5 reconstituted in peptide-nanodiscs and the detection of residues from the transmembrane domain by solution 19F NMR experiments. 19F NMR results revealing the interaction of the transmembrane domain of cytb5 with the full-length rabbit cytochrome P450 2B4 (CYP2B4) are also presented. We expect the results presented in this study to be useful to devise approaches to probe the structure, dynamics and functional roles of transmembrane domains of a membrane protein, and also to measure intermolecular 19F-19F distance constraints to determine the structural interactions between the transmembrane domains.
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Affiliation(s)
- Jia Bai
- Biophysics Program, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Jian Wang
- Biophysics Program, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Thirupathi Ravula
- Biophysics Program, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Sang-Choul Im
- Department of Internal Medicine, The University of Michigan, and VA Medical Center, Ann Arbor, MI 48105, USA
| | | | - Lucy Waskell
- Department of Anesthesiology, The University of Michigan, and VA Medical Center, Ann Arbor, MI 48105, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics Program, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA.
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11
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Conformational turn triggers regio-selectivity in the bioactivation of thiophene-contained compounds mediated by cytochrome P450. J Biol Inorg Chem 2019; 24:1023-1033. [PMID: 31506822 DOI: 10.1007/s00775-019-01699-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/24/2019] [Indexed: 10/26/2022]
Abstract
In the present work, we performed Density Functional Theory calculations to explore the bioactivation mechanism of thiophene-containing molecules mediated by P450s. For this purpose, relatively large size compounds, 2,5-diaminothiophene derivatives were selected particularly for this investigation. Here we found the successive regio-selectivity triggered by conformational turn played a significant role in the occurrence of bioactivation. 2,5-Diaminothiophene was oxidized to a 2,5-diimine thiophene-reactive intermediate by Compound I (Cpd I) through successive activations of two N-H bonds (H3-N11 and H1-N6). This reaction exhibited three special characteristics: (1) self-controlled regio-selectivity during the oxidation process. There was a large scale of conformational turn in the abstraction of the first H atom which triggers the selection of the second H for abstraction. (2) Proton-shuttle mechanism. In high spin (HS) state, proton-shuttle mechanism was observed for the abstraction of the second H atom. (3) Spin-selective manner. In protein environment, the energy barrier in HS state was much lower than that in low spin state. The novel proposed bioactivation mechanism of 2,5-diaminothiophene compounds can help us in rational design of thiophene-contained drugs avoiding the occurrence of bioactivation.
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12
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Campelo D, Esteves F, Brito Palma B, Costa Gomes B, Rueff J, Lautier T, Urban P, Truan G, Kranendonk M. Probing the Role of the Hinge Segment of Cytochrome P450 Oxidoreductase in the Interaction with Cytochrome P450. Int J Mol Sci 2018; 19:ijms19123914. [PMID: 30563285 PMCID: PMC6321550 DOI: 10.3390/ijms19123914] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 12/04/2018] [Accepted: 12/05/2018] [Indexed: 01/08/2023] Open
Abstract
NADPH-cytochrome P450 reductase (CPR) is the unique redox partner of microsomal cytochrome P450s (CYPs). CPR exists in a conformational equilibrium between open and closed conformations throughout its electron transfer (ET) function. Previously, we have shown that electrostatic and flexibility properties of the hinge segment of CPR are critical for ET. Three mutants of human CPR were studied (S243P, I245P and R246A) and combined with representative human drug-metabolizing CYPs (isoforms 1A2, 2A6 and 3A4). To probe the effect of these hinge mutations different experimental approaches were employed: CYP bioactivation capacity of pre-carcinogens, enzyme kinetic analysis, and effect of the ionic strength and cytochrome b5 (CYB5) on CYP activity. The hinge mutations influenced the bioactivation of pre-carcinogens, which seemed CYP isoform and substrate dependent. The deviations of Michaelis-Menten kinetic parameters uncovered tend to confirm this discrepancy, which was confirmed by CYP and hinge mutant specific salt/activity profiles. CPR/CYB5 competition experiments indicated a less important role of affinity in CPR/CYP interaction. Overall, our data suggest that the highly flexible hinge of CPR is responsible for the existence of a conformational aggregate of different open CPR conformers enabling ET-interaction with structural varied redox partners.
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Affiliation(s)
- Diana Campelo
- Center for Toxicogenomics and Human Health, Genetics, Oncology and Human Toxicology, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, 1150-082 Lisbon, Portugal.
| | - Francisco Esteves
- Center for Toxicogenomics and Human Health, Genetics, Oncology and Human Toxicology, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, 1150-082 Lisbon, Portugal.
| | - Bernardo Brito Palma
- Center for Toxicogenomics and Human Health, Genetics, Oncology and Human Toxicology, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, 1150-082 Lisbon, Portugal.
| | - Bruno Costa Gomes
- Center for Toxicogenomics and Human Health, Genetics, Oncology and Human Toxicology, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, 1150-082 Lisbon, Portugal.
| | - José Rueff
- Center for Toxicogenomics and Human Health, Genetics, Oncology and Human Toxicology, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, 1150-082 Lisbon, Portugal.
| | - Thomas Lautier
- LISBP, Université de Toulouse, CNRS, INRA, INSA, 31077 Toulouse CEDEX 04, France.
| | - Philippe Urban
- LISBP, Université de Toulouse, CNRS, INRA, INSA, 31077 Toulouse CEDEX 04, France.
| | - Gilles Truan
- LISBP, Université de Toulouse, CNRS, INRA, INSA, 31077 Toulouse CEDEX 04, France.
| | - Michel Kranendonk
- Center for Toxicogenomics and Human Health, Genetics, Oncology and Human Toxicology, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, 1150-082 Lisbon, Portugal.
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13
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Ravula T, Hardin NZ, Bai J, Im SC, Waskell L, Ramamoorthy A. Effect of polymer charge on functional reconstitution of membrane proteins in polymer nanodiscs. Chem Commun (Camb) 2018; 54:9615-9618. [PMID: 30094448 DOI: 10.1039/c8cc04184a] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Although there is a growing interest in using polymer lipid-nanodiscs, the polymer charge poses limitations for studies on membrane proteins. Here, we demonstrate the functional reconstitution of a large soluble-domain containing positively-charged ∼57 kDa cytochrome-P450 and negatively-charged ∼16 kDa cytochrome-b5 in lipid-nanodiscs, and the role of the polymer charge for high-resolution studies on membrane proteins.
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Affiliation(s)
- Thirupathi Ravula
- Biophysics and Department of Chemistry, University of Michigan Ann Arbor, Ann Arbor, MI 48109-1055, USA.
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14
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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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15
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Gentry KA, Zhang M, Im SC, Waskell L, Ramamoorthy A. Substrate mediated redox partner selectivity of cytochrome P450. Chem Commun (Camb) 2018; 54:5780-5783. [PMID: 29781479 DOI: 10.1039/c8cc02525h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Investigating the interplay between cytochrome-P450 and its redox partners (CPR and cytochrome-b5) is vital for understanding the metabolism of most hydrophobic drugs. Dynamic structural interactions with the ternary complex, with and without substrates, captured by NMR reveal a gating mechanism for redox partners to promote P450 function.
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Affiliation(s)
- Katherine A Gentry
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA.
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16
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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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17
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Chien CTH, Helfinger LR, Bostock MJ, Solt A, Tan YL, Nietlispach D. An Adaptable Phospholipid Membrane Mimetic System for Solution NMR Studies of Membrane Proteins. J Am Chem Soc 2017; 139:14829-14832. [PMID: 28990386 PMCID: PMC6109379 DOI: 10.1021/jacs.7b06730] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Based on the saposin-A (SapA) scaffold protein, we demonstrate the suitability of a size-adaptable phospholipid membrane-mimetic system for solution NMR studies of membrane proteins (MPs) under close-to-native conditions. The Salipro nanoparticle size can be tuned over a wide pH range by adjusting the saposin-to-lipid stoichiometry, enabling maintenance of sufficiently high amounts of phospholipid in the Salipro nanoparticle to mimic a realistic membrane environment while controlling the overall size to enable solution NMR for a range of MPs. Three representative MPs, including one G-protein-coupled receptor, were successfully incorporated into SapA-dimyristoylphosphatidylcholine nanoparticles and studied by solution NMR spectroscopy.
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Affiliation(s)
- Chih-Ta Henry Chien
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K
| | - Lukas R. Helfinger
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K
| | - Mark J. Bostock
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K
| | - Andras Solt
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K
| | - Yi Lei Tan
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K
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18
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Gentry KA, Prade E, Barnaba C, Zhang M, Mahajan M, Im SC, Anantharamaiah GM, Nagao S, Waskell L, Ramamoorthy A. Kinetic and Structural Characterization of the Effects of Membrane on the Complex of Cytochrome b 5 and Cytochrome c. Sci Rep 2017; 7:7793. [PMID: 28798301 PMCID: PMC5552742 DOI: 10.1038/s41598-017-08130-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 07/04/2017] [Indexed: 12/13/2022] Open
Abstract
Cytochrome b5 (cytb5) is a membrane protein vital for the regulation of cytochrome P450 (cytP450) metabolism and is capable of electron transfer to many redox partners. Here, using cyt c as a surrogate for cytP450, we report the effect of membrane on the interaction between full-length cytb5 and cyt c for the first time. As shown through stopped-flow kinetic experiments, electron transfer capable cytb5 - cyt c complexes were formed in the presence of bicelles and nanodiscs. Experimentally measured NMR parameters were used to map the cytb5-cyt c binding interface. Our experimental results identify differences in the binding epitope of cytb5 in the presence and absence of membrane. Notably, in the presence of membrane, cytb5 only engaged cyt c at its lower and upper clefts while the membrane-free cytb5 also uses a distal region. Using restraints generated from both cytb5 and cyt c, a complex structure was generated and a potential electron transfer pathway was identified. These results demonstrate the importance of studying protein-protein complex formation in membrane mimetic systems. Our results also demonstrate the successful preparation of novel peptide-based lipid nanodiscs, which are detergent-free and possesses size flexibility, and their use for NMR structural studies of membrane proteins.
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Affiliation(s)
| | - Elke Prade
- Biophysics Program, University of Michigan, Ann Arbor, MI, 48109, USA.,Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Carlo Barnaba
- Biophysics Program, University of Michigan, Ann Arbor, MI, 48109, USA.,Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Meng Zhang
- Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Mukesh Mahajan
- Biophysics Program, University of Michigan, Ann Arbor, MI, 48109, USA.,Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Sang-Choul Im
- Department of Anesthesiology, University of Michigan, and Veterans Affairs Medical Center, Ann Arbor, Michigan, 48105, USA
| | - G M Anantharamaiah
- Department of Medicine, UAB Medical Center, Birmingham, Alabama, 35294, USA
| | - Satoshi Nagao
- Graduate School of Material Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan
| | - Lucy Waskell
- Department of Anesthesiology, University of Michigan, and Veterans Affairs Medical Center, Ann Arbor, Michigan, 48105, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics Program, University of Michigan, Ann Arbor, MI, 48109, USA. .,Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA.
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19
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Bhatt MR, Khatri Y, Rodgers RJ, Martin LL. Role of cytochrome b5 in the modulation of the enzymatic activities of cytochrome P450 17α-hydroxylase/17,20-lyase (P450 17A1). J Steroid Biochem Mol Biol 2017; 170:2-18. [PMID: 26976652 DOI: 10.1016/j.jsbmb.2016.02.033] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 02/25/2016] [Accepted: 02/27/2016] [Indexed: 12/13/2022]
Abstract
Cytochrome b5 (cyt b5) is a small hemoprotein that plays a significant role in the modulation of activities of an important steroidogenic enzyme, cytochrome P450 17α-hydroxylase/17,20-lyase (P450 17A1, CYP17A1). Located in the zona fasciculata and zona reticularis of the adrenal cortex and in the gonads, P450 17A1 catalyzes two different reactions in the steroidogenic pathway; the 17α-hydroxylation and 17,20-lyase, in the endoplasmic reticulum of these respective tissues. The activities of P450 17A1 are regulated by cyt b5 that enhances the 17,20-lyase reaction by promoting the coupling of P450 17A1 and cytochrome P450 reductase (CPR), allosterically. Cyt b5 can also act as an electron donor to enhance the 16-ene-synthase activity of human P450 17A1. In this review, we discuss the many roles of cyt b5 and focus on the modulation of CYP17A1 activities by cyt b5 and the mechanisms involved.
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Affiliation(s)
- Megh Raj Bhatt
- Everest Biotech Pvt. Ltd., Khumaltar, Lalitpur, P.O. Box 21608, Kathmandu 44600, Nepal
| | - Yogan Khatri
- Institute of Biochemistry, Saarland University, 66123 Saarbrücken, Germany
| | - Raymond J Rodgers
- School of Medicine, Robinson Research Institute, University of Adelaide, Adelaide SA 5005, Australia
| | - Lisandra L Martin
- School of Chemistry, Monash University, Clayton, 3800, Victoria, Australia.
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20
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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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21
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Abstract
AbstractIncreasing evidence suggests that most proteins occur and function in complexes rather than as isolated entities when embedded in cellular membranes. Nuclear magnetic resonance (NMR) provides increasing possibilities to study structure, dynamics and assembly of such systems. In our review, we discuss recent methodological progress to study membrane–protein complexes (MPCs) by NMR, starting with expression, isotope-labeling and reconstitution protocols. We review approaches to deal with spectral complexity and limited spectral spectroscopic sensitivity that are usually encountered in NMR-based studies of MPCs. We highlight NMR applications in various classes of MPCs, including G-protein-coupled receptors, ion channels and retinal proteins and extend our discussion to protein–protein complexes that span entire cellular compartments or orchestrate processes such as protein transport across or within membranes. These examples demonstrate the growing potential of NMR-based studies of MPCs to provide critical insight into the energetics of protein–ligand and protein–protein interactions that underlie essential biological functions in cellular membranes.
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22
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Evidence that cytochrome b5 acts as a redox donor in CYP17A1 mediated androgen synthesis. Biochem Biophys Res Commun 2016; 477:202-8. [PMID: 27297105 DOI: 10.1016/j.bbrc.2016.06.043] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 06/09/2016] [Indexed: 02/02/2023]
Abstract
Cytochrome P450 17A1 (CYP17A1) is an important drug target for castration resistant prostate cancer. It is a bi-functional enzyme, catalyzing production of glucocorticoid precursors by hydroxylation of pregnene-nucleus, and androgen biosynthesis by a second CC lyase step, at the expense of glucocorticoid production. Cytochrome b5 (cyt b5) is known to be a key regulator of the androgen synthesis reaction in vivo, by a mechanism that is not well understood. Two hypotheses have been proposed for the mechanism by which cyt b5 increases androgen biosynthesis. Cyt b5 could act as an allosteric effector, binding to CYP17A1 and either changing its selective substrate affinity or altering the conformation of the P450 to increase the catalytic rate or decrease unproductive uncoupling channels. Alternatively, cyt b5 could act as a redox donor for supply of the second electron in the P450 cycle, reducing the oxyferrous complex to form the reactive peroxo-intermediate. To understand the mechanism of lyase enhancement by cyt b5, we generated a redox-inactive form of cyt b5, in which the heme is replaced with a Manganese-protoporphyrin IX (Mn-b5), and investigated enhancement of androgen producing lyase reaction by CYP17A1. Given the critical significance of a stable membrane anchor for all of the proteins involved and the need for controlled stoichiometric ratios, we employed the Nanodisc system for this study. The redox inactive form was observed to have no effect on the lyase reaction, while reactions with the normal heme-iron containing cyt b5 were enhanced ∼5 fold as compared to reactions in the absence of cyt b5. We also performed resonance Raman measurements on ferric CYP17A1 bound to Mn-b5. Upon addition of Mn-b5 to Nanodisc reconstituted CYP17A1, we observed clear evidence for the formation of a b5-CYP17A1 complex, as noted by changes in the porphyrin modes and alteration in the proximal FeS vibrational frequency. Thus, although Mn-b5 binds to CYP17A1, it is unable to enhance the lyase reaction, strongly suggesting that cyt b5 has a redox effector role in enhancement of the CYP17A1 mediated lyase reaction necessary for androgen synthesis.
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23
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D'Souza A, Mahajan M, Bhattacharjya S. Designed multi-stranded heme binding β-sheet peptides in membrane. Chem Sci 2016; 7:2563-2571. [PMID: 28660027 PMCID: PMC5477022 DOI: 10.1039/c5sc04108b] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 12/14/2015] [Indexed: 01/20/2023] Open
Abstract
Designed peptides demonstrating well-defined structures and functioning in membrane environment are of significant interest in developing novel proteins for membrane active biological processes including enzymes, electron transfer, ion channels and energy conversion. Heme proteins' ability to carry out multiple functions in nature has inspired the design of several helical heme binding peptides and proteins soluble in water and also recently in membrane. Naturally occurring β-sheet proteins are both water and membrane soluble, and are known to bind heme, however, designed heme binding β-sheet proteins are yet to be reported, plausibly because of the complex folding and difficulty in introducing heme binding sites in the β-sheet structures. Here, we describe the design, NMR structures and biochemical functional characterization of four stranded and six stranded membrane soluble β-sheet peptides that bind heme and di-heme, respectively. The designed peptides contain either DP-G or DP-DA residues for the nucleation of β-turns intended to stabilize multi-stranded β-sheet topologies and ligate heme with bis-His coordination between adjacent antiparallel β-strands. Furthermore, we have optimized a high affinity heme binding pocket, Kd ∼ nM range, in the adjacent β-strands by utilizing a series of four stranded β-sheet peptides employing β- and ω-amino acids. We find that there is a progressive increase in cofactor binding affinity in the designed peptides with the alkyl chain length of ω-amino acids. Notably, the six stranded β-sheet peptide binds two molecules of heme in a cooperative fashion. The designed peptides perform peroxidase activity with varying ability and efficiently carried out electron transfer with membrane associated protein cytochrome c. The current study demonstrates the designing of functional β-sheet proteins in a membrane environment and expands the repertoire of heme protein design.
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Affiliation(s)
- Areetha D'Souza
- School of Biological Sciences , 60 Nanyang Drive , 637551 , Singapore .
| | - Mukesh Mahajan
- School of Biological Sciences , 60 Nanyang Drive , 637551 , Singapore .
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24
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Jeřábek P, Florián J, Martínek V. Membrane-Anchored Cytochrome P450 1A2–Cytochrome b5 Complex Features an X-Shaped Contact between Antiparallel Transmembrane Helices. Chem Res Toxicol 2016; 29:626-36. [DOI: 10.1021/acs.chemrestox.5b00349] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Petr Jeřábek
- Department
of Biochemistry, Faculty of Science, Charles University in Prague, Albertov 2030, 128 43 Prague 2, Czech Republic
| | - Jan Florián
- Department
of Chemistry and Biochemistry, Loyola University Chicago, 1032 West Sheridan
Road, Chicago, Illinois 60660, United States
| | - Václav Martínek
- Department
of Biochemistry, Faculty of Science, Charles University in Prague, Albertov 2030, 128 43 Prague 2, Czech Republic
- Department of Teaching and Didactics of Chemistry, Faculty of Science, Charles University in Prague, Albertov 3, 128 43 Prague 2, Czech Republic
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25
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Zhang M, Huang R, Ackermann R, Im SC, Waskell L, Schwendeman A, Ramamoorthy A. Reconstitution of the Cytb5-CytP450 Complex in Nanodiscs for Structural Studies using NMR Spectroscopy. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201600073] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Meng Zhang
- Department of Chemistry; University of Michigan; Ann Arbor MI 48109-1055 USA
| | - Rui Huang
- Department of Chemistry; University of Michigan; Ann Arbor MI 48109-1055 USA
| | - Rose Ackermann
- Department of Medicinal Chemistry; The Biointerfaces Institute; University of Michigan; North Campus Research Complex; Ann Arbor MI 48109 USA
| | - Sang-Choul Im
- Department of Anesthesiology; University of Michigan and VA Medical Center; Ann Arbor MI 48105 USA
| | - Lucy Waskell
- Department of Anesthesiology; University of Michigan and VA Medical Center; Ann Arbor MI 48105 USA
| | - Anna Schwendeman
- Department of Medicinal Chemistry; The Biointerfaces Institute; University of Michigan; North Campus Research Complex; Ann Arbor MI 48109 USA
| | - Ayyalusamy Ramamoorthy
- Biophysics and Department of Chemistry; University of Michigan; Ann Arbor MI 48109-1055 USA
- Department of Chemistry; University of Michigan; Ann Arbor MI 48109-1055 USA
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26
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Zhang M, Huang R, Ackermann R, Im SC, Waskell L, Schwendeman A, Ramamoorthy A. Reconstitution of the Cytb5-CytP450 Complex in Nanodiscs for Structural Studies using NMR Spectroscopy. Angew Chem Int Ed Engl 2016; 55:4497-9. [PMID: 26924779 DOI: 10.1002/anie.201600073] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 01/22/2016] [Indexed: 11/05/2022]
Abstract
Cytochrome P450s (P450s) are a superfamily of enzymes responsible for the catalysis of a wide range of substrates. Dynamic interactions between full-length membrane-bound P450 and its redox partner cytochrome b5 (cytb5 ) have been found to be important for the enzymatic activity of P450. However, the stability of the circa 70 kDa membrane-bound complex in model membranes renders high-resolution structural NMR studies particularly difficult. To overcome these challenges, reconstitution of the P450-cytb5 complex in peptide-based nanodiscs, containing no detergents, has been demonstrated, which are characterized by size exclusion chromatography and NMR spectroscopy. In addition, NMR experiments are used to identify the binding interface of the P450-cytb5 complex in the nanodisc. This is the first successful demonstration of a protein-protein complex in a nanodisc using NMR structural studies and should be useful to obtain valuable structural information on membrane-bound protein complexes.
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Affiliation(s)
- Meng Zhang
- Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109-1055, USA
| | - Rui Huang
- Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109-1055, USA
| | - Rose Ackermann
- Department of Medicinal Chemistry, The Biointerfaces Institute, University of Michigan, North Campus Research Complex, Ann Arbor, MI, 48109, USA
| | - Sang-Choul Im
- Department of Anesthesiology, University of Michigan and VA Medical Center, Ann Arbor, MI, 48105, USA
| | - Lucy Waskell
- Department of Anesthesiology, University of Michigan and VA Medical Center, Ann Arbor, MI, 48105, USA
| | - Anna Schwendeman
- Department of Medicinal Chemistry, The Biointerfaces Institute, University of Michigan, North Campus Research Complex, Ann Arbor, MI, 48109, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109-1055, USA. .,Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109-1055, USA.
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27
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Mapping the Free Energy Landscape of PKA Inhibition and Activation: A Double-Conformational Selection Model for the Tandem cAMP-Binding Domains of PKA RIα. PLoS Biol 2015; 13:e1002305. [PMID: 26618408 PMCID: PMC4664472 DOI: 10.1371/journal.pbio.1002305] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 10/22/2015] [Indexed: 01/31/2023] Open
Abstract
Protein Kinase A (PKA) is the major receptor for the cyclic adenosine monophosphate (cAMP) secondary messenger in eukaryotes. cAMP binds to two tandem cAMP-binding domains (CBD-A and -B) within the regulatory subunit of PKA (R), unleashing the activity of the catalytic subunit (C). While CBD-A in RIα is required for PKA inhibition and activation, CBD-B functions as a “gatekeeper” domain that modulates the control exerted by CBD-A. Preliminary evidence suggests that CBD-B dynamics are critical for its gatekeeper function. To test this hypothesis, here we investigate by Nuclear Magnetic Resonance (NMR) the two-domain construct RIα (91–379) in its apo, cAMP2, and C-bound forms. Our comparative NMR analyses lead to a double conformational selection model in which each apo CBD dynamically samples both active and inactive states independently of the adjacent CBD within a nearly degenerate free energy landscape. Such degeneracy is critical to explain the sensitivity of CBD-B to weak interactions with C and its high affinity for cAMP. Binding of cAMP eliminates this degeneracy, as it selectively stabilizes the active conformation within each CBD and inter-CBD contacts, which require both cAMP and W260. The latter is contributed by CBD-B and mediates capping of the cAMP bound to CBD-A. The inter-CBD interface is dispensable for intra-CBD conformational selection, but is indispensable for full activation of PKA as it occludes C-subunit recognition sites within CBD-A. In addition, the two structurally homologous cAMP-bound CBDs exhibit marked differences in their residual dynamics profiles, supporting the notion that conservation of structure does not necessarily imply conservation of dynamics. Protein Kinase A (PKA) is the major receptor for the cAMP secondary messenger in eukaryotes. This study shows how PKA's regulatory subunit dynamically samples a degenerate free energy landscape that controls affinities for the catalytic subunit and cAMP; intra-domain conformational selection by cAMP controls inter-domain interactions and PKA activation. Cyclic adenosine monophosphate (cAMP) is a messenger molecule produced within cells to control cellular metabolism in response to external stimuli. Protein Kinase A (PKA) is the major receptor for cAMP. cAMP binds to tandem cAMP-binding domains (CBD-A and -B) within the regulatory subunits of PKA (R), unleashing the activity of the catalytic subunit (C). While CBD-A is required for C-subunit inhibition and activation, in RIα CBD-B functions as a “gatekeeper” domain that modulates the control exerted by CBD-A. However, it is not currently clear how ligand binding and dynamics of CBD-B mediate its gatekeeper function. We comparatively analyzed by Nuclear Magnetic Resonance (NMR) a two-domain construct of the regulatory subunit RIα with no ligand, with cAMP2 bound, and the C-bound form. These data show that both CBDs can exist in a system of uncorrelated conformational selection as both can independently sample activated and inactivated states (in what is known as a nearly degenerate free energy landscape). This explains why both RIα CBDs exhibit a higher cAMP-affinity than other cAMP receptors. Once cAMP has bound, the degeneracy is lost and dissociation of the kinase subunit is promoted through a combination of intra-domain conformational selection and changes in inter-CBD orientation. The proposed model—a double-conformational selection model—provides a general framework to interpret the effect of PKA mutations that have been reported in rare human disorders such as Carney complex and Acrodysostosis.
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Li Q, Wong YL, Yueqi Lee M, Li Y, Kang C. Solution structure of the transmembrane domain of the mouse erythropoietin receptor in detergent micelles. Sci Rep 2015; 5:13586. [PMID: 26316120 PMCID: PMC4551963 DOI: 10.1038/srep13586] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 07/31/2015] [Indexed: 12/19/2022] Open
Abstract
Erythropoiesis is regulated by the erythropoietin receptor (EpoR) binding to its ligand. The transmembrane domain (TMD) and the juxtamembrane (JM) regions of the EpoR are important for signal transduction across the cell membrane. We report a solution NMR study of the mouse erythropoietin receptor (mEpoR) comprising the TMD and the JM regions reconstituted in dodecylphosphocholine (DPC) micelles. The TMD and the C-terminal JM region of the mEpoR are mainly α-helical, adopting a similar structure to those of the human EpoR. Residues from S216 to T219 in mEpoR form a short helix. Relaxation study demonstrates that the TMD of the mEpoR is rigid whilst the N-terminal region preceding the TMD is flexible. Fluorescence spectroscopy and sequence analysis indicate that the C-terminal JM region is exposed to the solvent. Helix wheel result shows that there is hydrophilic patch in the TMD of the mEpoR formed by residues S231, S238 and T242, and these residues might be important for the receptor dimerization.
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Affiliation(s)
- Qingxin Li
- Institute of Chemical &Engineering Sciences, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Ying Lei Wong
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore, 138669 Singapore
| | - Michelle Yueqi Lee
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore, 138669 Singapore
| | - Yan Li
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore, 138669 Singapore
| | - CongBao Kang
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore, 138669 Singapore
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