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Bedewy WA, Mulawka JW, Adler MJ. Classifying covalent protein binders by their targeted binding site. Bioorg Med Chem Lett 2025; 117:130067. [PMID: 39667507 DOI: 10.1016/j.bmcl.2024.130067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2024] [Revised: 12/04/2024] [Accepted: 12/05/2024] [Indexed: 12/14/2024]
Abstract
Covalent protein targeting represents a powerful tool for protein characterization, identification, and activity modulation. The safety of covalent therapeutics was questioned for many years due to the possibility of off-target binding and subsequent potential toxicity. Researchers have recently, however, demonstrated many covalent binders as safe, potent, and long-acting therapeutics. Moreover, they have achieved selective targeting among proteins with high structural similarities, overcome mutation-induced resistance, and obtained higher potency compared to non-covalent binders. In this review, we highlight the different classes of binding sites on a target protein that could be addressed by a covalent binder. Upon folding, proteins generate various concavities available for covalent modifications. Selective targeting to a specific site is driven by differences in the geometry and physicochemical properties of the binding pocket residues as well as the geometry and reactivity of the covalent modifier "warhead". According to the warhead reactivity and the nature of the binding region, covalent binders can alter or lock a targeted protein conformation and inhibit or enhance its activity. We survey these various modification sites using case studies of recently discovered covalent binders, bringing to the fore the versatile application of covalent protein binders with respect to drug discovery approaches.
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Affiliation(s)
- Walaa A Bedewy
- Department of Chemistry & Biology, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada; Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Helwan University, Egypt.
| | - John W Mulawka
- Department of Chemistry & Biology, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada
| | - Marc J Adler
- Department of Chemistry & Biology, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada.
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Mahato C, Pal S, Kuiry H, Das D. Pathway-Dependent Catalytic Activity of Short-Peptide-Based Metallozyme: From Promiscuous Activity to Cascade Reaction. NANO LETTERS 2025. [PMID: 39893659 DOI: 10.1021/acs.nanolett.4c06230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2025]
Abstract
Many natural enzymes contain metal ions as cofactors in the active site for biological activity. However, the pathway of the introduction of metal ions in the earliest protein folds for the emergence of higher catalytic activity remains an intriguing open question. Herein, we demonstrate that pathway-dependent self-assembly of short-peptide-based metallozymes results in differences in catalytic activity. Short-peptide-based amyloids with solvent exposed arrays of colocalized catalytic units are able to bind highly soluble Cu2+ ions to demonstrate oxidase-like and RNase-like activity (promiscuity). Further, the metallozyme was able to exhibit higher hydrolase-oxidase cascade activity compared to the mixture of natural enzymes, esterase, and laccase. The collaboration between short-peptide-based amyloid microphases and metal ions suggests that metallozymes might have played a pivotal role in early metabolic processes and biopolymer evolution on the prebiotic earth.
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Affiliation(s)
- Chiranjit Mahato
- Department of Chemical Sciences & Centre for Advanced Functional Materials, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal 741246, India
| | - Sumit Pal
- Department of Chemical Sciences & Centre for Advanced Functional Materials, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal 741246, India
| | - Himangshu Kuiry
- Department of Chemical Sciences & Centre for Advanced Functional Materials, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal 741246, India
| | - Dibyendu Das
- Department of Chemical Sciences & Centre for Advanced Functional Materials, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal 741246, India
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3
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Chiou SL, Chang CY, Chu J. "Cofactors" for Natural Products. ChemMedChem 2025:e202400498. [PMID: 39822069 DOI: 10.1002/cmdc.202400498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2024] [Revised: 12/10/2024] [Accepted: 01/14/2025] [Indexed: 01/19/2025]
Abstract
Cofactors are non-protein entities necessary for proteins to operate. They provide "functional groups" beyond those of the 20 canonical amino acids and enable proteins to carry out more diverse functions. Such a viewpoint is rarely mentioned, if at all, when it comes to natural products and is the theme of this Concept. Even though the mechanisms of action (MOA) of only a few natural products are known to require cofactors, we believe that cofactor mediated MOA in natural products are far more prevalent than what we currently know. Bleomycin is a case in point. It binds iron cation to form a pseudoenzyme that generates reactive oxygen species. As another example, calcium cations induce laspartomycin to "fold" into the active conformation. Iron and calcium are bona fide cofactors for bleomycin and laspartomycin, respectively, as these natural products do not display their characteristic anticancer and antibacterial activities without Fe(II) and Ca(II). These types of cofactor mediated MOA in natural products were discovered mostly serendipitously, and being conscious of such a possibility is the first step toward identifying more novel chemistry that nature performs.
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Affiliation(s)
- Shao-Lun Chiou
- Department of Chemistry, National Taiwan University, 106319, Taipei City, Taiwan
| | - Chin-Yuan Chang
- Department of Biological Science and Technology, National Yang Ming Chiao Tung University, 300193, Hsinchu City, Taiwan
| | - John Chu
- Department of Chemistry, National Taiwan University, 106319, Taipei City, Taiwan
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Piller P, Reiterer P, Semeraro EF, Pabst G. Metal ion cofactors modulate integral enzyme activity by varying differential membrane curvature stress. RSC APPLIED INTERFACES 2025; 2:69-73. [PMID: 39479198 PMCID: PMC11514723 DOI: 10.1039/d4lf00309h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2024] [Accepted: 10/18/2024] [Indexed: 11/02/2024]
Abstract
Metal ions are well-known cofactors of protein function and stability. In the case of the integral membrane enzyme OmpLA (outer membrane phospholipase A) the active dimer is stabilized by calcium ions. We studied the lipid hydrolysis kinetics of OmpLA in charge-neutral and charged membranes with symmetric or asymmetric transbilayer lipid distributions. In charge-neutral membranes, OmpLA was more active in symmetric bilayers due to the lower differential curvature stress between membrane leaflets. Strikingly, this behavior was completely reversed in charged bilayers. Measurements revealed intrinsic molecular shape changes in the charged lipids upon addition of calcium. This effectively reduces the differential curvature stress in charged asymmetric membranes leading to increased protein activity. This conclusion is further supported by similar effects observed upon the addition of sodium ions, which also alter the shape of the lipids, but do not specifically interact with the protein. Additional lipid-protein interactions likely contribute to this phenomenon. Our findings demonstrate that ion cofactors not only interact directly with membrane proteins but also modulate protein activity indirectly by altering the effective molecular shape of charged lipid species.
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Affiliation(s)
- Paulina Piller
- Biophysics, Institute of Molecular Biosciences, University of Graz NAWI Graz Graz Austria +43 316 380 4989
- BioTechMed Graz Graz Austria
- Field of Excellence BioHealth Graz Austria
| | - Paul Reiterer
- Biophysics, Institute of Molecular Biosciences, University of Graz NAWI Graz Graz Austria +43 316 380 4989
- BioTechMed Graz Graz Austria
- Field of Excellence BioHealth Graz Austria
| | - Enrico F Semeraro
- Biophysics, Institute of Molecular Biosciences, University of Graz NAWI Graz Graz Austria +43 316 380 4989
- BioTechMed Graz Graz Austria
- Field of Excellence BioHealth Graz Austria
| | - Georg Pabst
- Biophysics, Institute of Molecular Biosciences, University of Graz NAWI Graz Graz Austria +43 316 380 4989
- BioTechMed Graz Graz Austria
- Field of Excellence BioHealth Graz Austria
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Srivastava G, Liu M, Ni X, Pu L, Brylinski M. Machine Learning Techniques to Infer Protein Structure and Function from Sequences: A Comprehensive Review. Methods Mol Biol 2025; 2867:79-104. [PMID: 39576576 DOI: 10.1007/978-1-0716-4196-5_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2024]
Abstract
The elucidation of protein structure and function plays a pivotal role in understanding biological processes and facilitating drug discovery. With the exponential growth of protein sequence data, machine learning techniques have emerged as powerful tools for predicting protein characteristics from sequences alone. This review provides a comprehensive overview of the importance and application of machine learning in inferring protein structure and function. We discuss various machine learning approaches, primarily focusing on convolutional neural networks and natural language processing, and their utilization in predicting protein secondary and tertiary structures, residue-residue contacts, protein function, and subcellular localization. Furthermore, we highlight the challenges associated with using machine learning techniques in this context, such as the availability of high-quality training datasets and the interpretability of models. We also delve into the latest progress in the field concerning the advancements made in the development of intricate deep learning architectures. Overall, this review underscores the significance of machine learning in advancing our understanding of protein structure and function, and its potential to revolutionize drug discovery and personalized medicine.
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Affiliation(s)
- Gopal Srivastava
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - Mengmeng Liu
- Division of Electrical and Computer Engineering, Louisiana State University, Baton Rouge, LA, USA
| | - Xialong Ni
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - Limeng Pu
- Center for Computation and Technology, Louisiana State University, Baton Rouge, LA, USA
| | - Michal Brylinski
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA.
- Center for Computation and Technology, Louisiana State University, Baton Rouge, LA, USA.
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6
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Choi SI, Jin Y, Choi Y, Seong BL. Beyond Misfolding: A New Paradigm for the Relationship Between Protein Folding and Aggregation. Int J Mol Sci 2024; 26:53. [PMID: 39795912 PMCID: PMC11720324 DOI: 10.3390/ijms26010053] [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: 11/29/2024] [Revised: 12/19/2024] [Accepted: 12/21/2024] [Indexed: 01/13/2025] Open
Abstract
Aggregation is intricately linked to protein folding, necessitating a precise understanding of their relationship. Traditionally, aggregation has been viewed primarily as a sequential consequence of protein folding and misfolding. However, this conventional paradigm is inherently incomplete and can be deeply misleading. Remarkably, it fails to adequately explain how intrinsic and extrinsic factors, such as charges and cellular macromolecules, prevent intermolecular aggregation independently of intramolecular protein folding and structure. The pervasive inconsistencies between protein folding and aggregation call for a new framework. In all combined reactions of molecules, both intramolecular and intermolecular rate (or equilibrium) constants are mutually independent; accordingly, intrinsic and extrinsic factors independently affect both rate constants. This universal principle, when applied to protein folding and aggregation, indicates that they should be treated as two independent yet interconnected processes. Based on this principle, a new framework provides groundbreaking insights into misfolding, Anfinsen's thermodynamic hypothesis, molecular chaperones, intrinsic chaperone-like activities of cellular macromolecules, intermolecular repulsive force-driven aggregation inhibition, proteome solubility maintenance, and proteinopathies. Consequently, this paradigm shift not only refines our current understanding but also offers a more comprehensive view of how aggregation is coupled to protein folding in the complex cellular milieu.
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Affiliation(s)
- Seong Il Choi
- Department of Pediatrics, Severance Hospital, Institute of Allergy, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
- Vaccine Innovative Technology ALliance (VITAL)-Korea, Seoul 03722, Republic of Korea; (Y.J.); (Y.C.)
| | - Yoontae Jin
- Vaccine Innovative Technology ALliance (VITAL)-Korea, Seoul 03722, Republic of Korea; (Y.J.); (Y.C.)
- Department of Microbiology and Immunology, Institute for Immunology and Immunological Diseases, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Yura Choi
- Vaccine Innovative Technology ALliance (VITAL)-Korea, Seoul 03722, Republic of Korea; (Y.J.); (Y.C.)
- Department of Integrative Biotechnology, Yonsei University, Incheon 21983, Republic of Korea
| | - Baik L. Seong
- Vaccine Innovative Technology ALliance (VITAL)-Korea, Seoul 03722, Republic of Korea; (Y.J.); (Y.C.)
- Department of Microbiology, College of Medicine, Yonsei University, Seoul 03722, Republic of Korea
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Abstract
Covering: from 2000 up to the very early part of 2023S-Adenosyl-L-methionine (SAM) is a naturally occurring trialkyl sulfonium molecule that is typically associated with biological methyltransfer reactions. However, SAM is also known to donate methylene, aminocarboxypropyl, adenosyl and amino moieties during natural product biosynthetic reactions. The reaction scope is further expanded as SAM itself can be modified prior to the group transfer such that a SAM-derived carboxymethyl or aminopropyl moiety can also be transferred. Moreover, the sulfonium cation in SAM has itself been found to be critical for several other enzymatic transformations. Thus, while many SAM-dependent enzymes are characterized by a methyltransferase fold, not all of them are necessarily methyltransferases. Furthermore, other SAM-dependent enzymes do not possess such a structural feature suggesting diversification along different evolutionary lineages. Despite the biological versatility of SAM, it nevertheless parallels the chemistry of sulfonium compounds used in organic synthesis. The question thus becomes how enzymes catalyze distinct transformations via subtle differences in their active sites. This review summarizes recent advances in the discovery of novel SAM utilizing enzymes that rely on Lewis acid/base chemistry as opposed to radical mechanisms of catalysis. The examples are categorized based on the presence of a methyltransferase fold and the role played by SAM within the context of known sulfonium chemistry.
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Affiliation(s)
- Yu-Hsuan Lee
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA.
| | - Daan Ren
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA.
| | - Byungsun Jeon
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA.
| | - Hung-Wen Liu
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA.
- Division of Chemical Biology & Medicinal Chemistry, College of Pharmacy, University of Texas at Austin, Austin, TX 78712, USA
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Beygmoradi A, Homaei A, Hemmati R, Fernandes P. Recombinant protein expression: Challenges in production and folding related matters. Int J Biol Macromol 2023; 233:123407. [PMID: 36708896 DOI: 10.1016/j.ijbiomac.2023.123407] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/13/2023] [Accepted: 01/20/2023] [Indexed: 01/26/2023]
Abstract
Protein folding is a biophysical process by which proteins reach a specific three-dimensional structure. The amino acid sequence of a polypeptide chain contains all the information needed to determine the final three-dimensional structure of a protein. When producing a recombinant protein, several problems can occur, including proteolysis, incorrect folding, formation of inclusion bodies, or protein aggregation, whereby the protein loses its natural structure. To overcome such limitations, several strategies have been developed to address each specific issue. Identification of proper protein refolding conditions can be challenging, and to tackle this high throughput screening for different recombinant protein folding conditions can prove a sound solution. Different approaches have emerged to tackle refolding issues. One particular approach to address folding issues involves molecular chaperones, highly conserved proteins that contribute to proper folding by shielding folding proteins from other proteins that could hinder the process. Proper protein folding is one of the main prerequisites for post-translational modifications. Incorrect folding, if not dealt with, can lead to a buildup of protein misfoldings that damage cells and cause widespread abnormalities. Said post-translational modifications, widespread in eukaryotes, are critical for protein structure, function and biological activity. Incorrect post-translational protein modifications may lead to individual consequences or aggregation of therapeutic proteins. In this review article, we have tried to examine some key aspects of recombinant protein expression. Accordingly, the relevance of these proteins is highlighted, major problems related to the production of recombinant protein and to refolding issues are pinpointed and suggested solutions are presented. An overview of post-translational modification, their biological significance and methods of identification are also provided. Overall, the work is expected to illustrate challenges in recombinant protein expression.
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Affiliation(s)
- Azadeh Beygmoradi
- Department of Marine Biology, Faculty of Marine Science and Technology, University of Hormozgan, Bandar Abbas, Iran
| | - Ahmad Homaei
- Department of Marine Biology, Faculty of Marine Science and Technology, University of Hormozgan, Bandar Abbas, Iran.
| | - Roohullah Hemmati
- Department of Biology, Faculty of Basic Sciences, Shahrekord University, Shahrekord, Iran
| | - Pedro Fernandes
- DREAMS and Faculdade de Engenharia, Universidade Lusófona de Humanidades e Tecnologias, Av. Campo Grande 376, 1749-024 Lisboa, Portugal; iBB-Institute for Bioengineering and Biosciences and Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
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Guo HB, Varaljay VA, Kedziora G, Taylor K, Farajollahi S, Lombardo N, Harper E, Hung C, Gross M, Perminov A, Dennis P, Kelley-Loughnane N, Berry R. Accurate prediction by AlphaFold2 for ligand binding in a reductive dehalogenase and implications for PFAS (per- and polyfluoroalkyl substance) biodegradation. Sci Rep 2023; 13:4082. [PMID: 36906658 PMCID: PMC10008544 DOI: 10.1038/s41598-023-30310-x] [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: 09/12/2022] [Accepted: 02/21/2023] [Indexed: 03/13/2023] Open
Abstract
Despite the success of AlphaFold2 (AF2), it is unclear how AF2 models accommodate for ligand binding. Here, we start with a protein sequence from Acidimicrobiaceae TMED77 (T7RdhA) with potential for catalyzing the degradation of per- and polyfluoroalkyl substances (PFASs). AF2 models and experiments identified T7RdhA as a corrinoid iron-sulfur protein (CoFeSP) which uses a norpseudo-cobalamin (BVQ) cofactor and two Fe4S4 iron-sulfur clusters for catalysis. Docking and molecular dynamics simulations suggest that T7RdhA uses perfluorooctanoic acetate (PFOA) as a substrate, supporting the reported defluorination activity of its homolog, A6RdhA. We showed that AF2 provides processual (dynamic) predictions for the binding pockets of ligands (cofactors and/or substrates). Because the pLDDT scores provided by AF2 reflect the protein native states in complex with ligands as the evolutionary constraints, the Evoformer network of AF2 predicts protein structures and residue flexibility in complex with the ligands, i.e., in their native states. Therefore, an apo-protein predicted by AF2 is actually a holo-protein awaiting ligands.
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Affiliation(s)
- Hao-Bo Guo
- Material and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, 45433, USA
- UES Inc., Dayton, OH, 45432, USA
| | - Vanessa A Varaljay
- Material and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, 45433, USA
| | - Gary Kedziora
- GDIT Inc., Wright-Patterson Air Force Base, Dayton, OH, 45433, USA
| | - Kimberly Taylor
- Material and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, 45433, USA
- UES Inc., Dayton, OH, 45432, USA
| | - Sanaz Farajollahi
- Material and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, 45433, USA
- UES Inc., Dayton, OH, 45432, USA
| | - Nina Lombardo
- Material and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, 45433, USA
- UES Inc., Dayton, OH, 45432, USA
| | - Eric Harper
- Material and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, 45433, USA
| | - Chia Hung
- Material and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, 45433, USA
| | - Marie Gross
- Material and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, 45433, USA
- University of Dayton, Dayton, OH, 45469, USA
| | - Alexander Perminov
- Material and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, 45433, USA
- Miami University, Oxford, OH, 45056, USA
| | - Patrick Dennis
- Material and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, 45433, USA
| | - Nancy Kelley-Loughnane
- Material and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, 45433, USA.
| | - Rajiv Berry
- Material and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, 45433, USA.
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Foroutannejad S, Good LL, Lin C, Carter ZI, Tadesse MG, Lucius AL, Crane BR, Maillard RA. The cofactor-dependent folding mechanism of Drosophila cryptochrome revealed by single-molecule pulling experiments. Nat Commun 2023; 14:1057. [PMID: 36828841 PMCID: PMC9958137 DOI: 10.1038/s41467-023-36701-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 02/10/2023] [Indexed: 02/26/2023] Open
Abstract
The link between cofactor binding and protein activity is well-established. However, how cofactor interactions modulate folding of large proteins remains unknown. We use optical tweezers, clustering and global fitting to dissect the folding mechanism of Drosophila cryptochrome (dCRY), a 542-residue protein that binds FAD, one of the most chemically and structurally complex cofactors in nature. We show that the first dCRY parts to fold are independent of FAD, but later steps are FAD-driven as the remaining polypeptide folds around the cofactor. FAD binds to largely unfolded intermediates, yet with association kinetics above the diffusion-limit. Interestingly, not all FAD moieties are required for folding: whereas the isoalloxazine ring linked to ribitol and one phosphate is sufficient to drive complete folding, the adenosine ring with phosphates only leads to partial folding. Lastly, we propose a dCRY folding model where regions that undergo conformational transitions during signal transduction are the last to fold.
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Affiliation(s)
| | - Lydia L Good
- Department of Chemistry, Georgetown University, Washington, DC, USA
| | - Changfan Lin
- Department of Chemistry & Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Zachariah I Carter
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mahlet G Tadesse
- Department of Mathematics and Statistics, Georgetown University, Washington, DC, USA
| | - Aaron L Lucius
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Brian R Crane
- Department of Chemistry & Chemical Biology, Cornell University, Ithaca, NY, USA
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Li H. Single Molecule Force Spectroscopy Studies on Metalloproteins: Opportunities and Challenges. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:1345-1353. [PMID: 36647634 DOI: 10.1021/acs.langmuir.2c03332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Metalloproteins play important roles in a wide range of biological processes. Elucidating the mechanisms via which metalloproteins fold and constitute their metal centers is critical to the understanding of the functions and dynamics of metalloproteins. Owing to its superior force and length resolution, single-molecule force spectroscopy (SMFS) has evolved into a powerful tool to probe the unfolding and folding mechanisms of metalloproteins at the single level by forcing metalloproteins to unfold and then refold along a reaction coordinate defined by the applied stretching force. The folding of metalloproteins is complex and involves two interwound processes, the folding of the polypeptide chain and the constitution of the metal center. Experimental studies of the folding of metalloproteins are challenging. SMFS studies have allowed researchers to directly probe the folding and unfolding of metalloproteins at the single-molecule level and the effect of metal centers on the folding-unfolding energy landscape of metalloproteins. New mechanistic insights on the folding and unfolding of some metalloproteins have been obtained, demonstrating the power and unique advantages that SMFS techniques may offer. In this Perspective, using calcium-binding proteins and small iron-sulfur proteins as examples, I provide a concise overview of the information and insights that SMFS studies have provided to understand the folding and unfolding of metalloproteins. I also discuss the opportunities and challenges that are present in this fast-progressing area of research.
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Affiliation(s)
- Hongbin Li
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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12
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Kachhawaha K, Singh S, Joshi K, Nain P, Singh SK. Bioprocessing of recombinant proteins from Escherichia coli inclusion bodies: insights from structure-function relationship for novel applications. Prep Biochem Biotechnol 2022; 53:728-752. [PMID: 36534636 DOI: 10.1080/10826068.2022.2155835] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The formation of inclusion bodies (IBs) during expression of recombinant therapeutic proteins using E. coli is a significant hurdle in producing high-quality, safe, and efficacious medicines. The improved understanding of the structure-function relationship of the IBs has resulted in the development of novel biotechnologies that have streamlined the isolation, solubilization, refolding, and purification of the active functional proteins from the bacterial IBs. Together, this overall effort promises to radically improve the scope of experimental biology of therapeutic protein production and expand new prospects in IBs usage. Notably, the IBs are increasingly used for applications in more pristine areas such as drug delivery and material sciences. In this review, we intend to provide a comprehensive picture of the bio-processing of bacterial IBs, including assessing critical gaps that still need to be addressed and potential solutions to overcome them. We expect this review to be a useful resource for those working in the area of protein refolding and therapeutic protein production.
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Affiliation(s)
- Kajal Kachhawaha
- School of Biochemical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Santanu Singh
- School of Biochemical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Khyati Joshi
- School of Biochemical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Priyanka Nain
- Department of Chemical and Bimolecular Engineering, University of Delaware, Newark, DE, USA
| | - Sumit K Singh
- School of Biochemical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
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13
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Hoffnagle AM, Eng VH, Markel U, Tezcan F. Computationally Guided Redesign of a Heme-free Cytochrome with Native-like Structure and Stability. Biochemistry 2022; 61:2063-2072. [PMID: 36106943 PMCID: PMC9949987 DOI: 10.1021/acs.biochem.2c00369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Metals can play key roles in stabilizing protein structures, but ensuring their proper incorporation is a challenge when a metalloprotein is overexpressed in a non-native cellular environment. Here, we have used computational protein design tools to redesign cytochrome b562 (cyt b562), which relies on the binding of its heme cofactor to achieve its proper fold, into a stable, heme-free protein. The resulting protein, ApoCyt, features only four mutations and no metal-ligand or covalent bonds, yet displays improved stability over cyt b562. Mutagenesis studies and X-ray crystal structures reveal that the increase in stability is due to the computationally prescribed mutations, which stabilize the protein fold through a combination of hydrophobic packing interactions, hydrogen bonds, and cation-π interactions. Upon installation of the relevant mutations, ApoCyt is capable of assembling into previously reported, cytochrome-based trimeric and tetrameric assemblies, demonstrating that ApoCyt retains the structure and assembly properties of cyt b562. The successful design of ApoCyt therefore enables further functional diversification of cytochrome-based assemblies and demonstrates that structural metal cofactors can be replaced by a small number of well-designed, non-covalent interactions.
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Affiliation(s)
| | | | | | - F.Akif Tezcan
- Corresponding Author: F. Akif Tezcan, Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States.
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14
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Schnizlein MK, Young VB. Capturing the environment of the Clostridioides difficile infection cycle. Nat Rev Gastroenterol Hepatol 2022; 19:508-520. [PMID: 35468953 DOI: 10.1038/s41575-022-00610-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/21/2022] [Indexed: 12/11/2022]
Abstract
Clostridioides difficile (formerly Clostridium difficile) infection is a substantial health and economic burden worldwide. Great strides have been made over the past several years in characterizing the physiology of C. difficile infection, particularly regarding how gut microorganisms and their host work together to provide colonization resistance. As mammalian hosts and their indigenous gut microbiota have co-evolved, they have formed a complex yet stable relationship that prevents invading microorganisms from establishing themselves. In this Review, we discuss the latest advances in our understanding of C. difficile physiology that have contributed to its success as a pathogen, including its versatile survival factors and ability to adapt to unique niches. Using discoveries regarding microorganism-host and microorganism-microorganism interactions that constitute colonization resistance, we place C. difficile within the fiercely competitive gut environment. A comprehensive understanding of these relationships is required to continue the development of precision medicine-based treatments for C. difficile infection.
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Affiliation(s)
- Matthew K Schnizlein
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Vincent B Young
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA.
- Department of Internal Medicine/Division of Infectious Diseases, University of Michigan Medical School, Ann Arbor, MI, USA.
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15
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Endophytic fungi: a potential source of industrial enzyme producers. 3 Biotech 2022; 12:86. [PMID: 35273898 PMCID: PMC8894535 DOI: 10.1007/s13205-022-03145-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 02/09/2022] [Indexed: 11/01/2022] Open
Abstract
Microbial enzymes have gained interest for their widespread use in various industries and medicine due to their stability, ease of production, and optimization. Endophytic fungi in plant tissues produce a wide range of secondary metabolites and enzymes, which exhibit a variety of biological activities. The present review illustrates promising applications of enzymes produced by endophytic fungi and discusses the characteristic features of the enzymes, application of the endophytic fungal enzymes in therapeutics, agriculture, food, and biofuel industries. Endophytic fungi producing ligninolytic enzymes have possible biotechnological applications in lignocellulosic biorefineries. The global market of industrially important enzymes, challenges, and future prospects are illustrated. However, the commercialization of endophytic fungal enzymes for industrial purposes is yet to be explored. The present review suggests that endophytic fungi can produce various enzymes and may become a novel source for upscaling the production of enzymes of industrial use.
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16
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Ge X, Zhang W, Putnis CV, Wang L. Molecular mechanisms for the humic acid-enhanced formation of the ordered secondary structure of a conserved catalytic domain in phytase. Phys Chem Chem Phys 2022; 24:4493-4503. [PMID: 35113120 DOI: 10.1039/d2cp00054g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Changes in the secondary structure of phytase, particularly the conserved active catalytic domain (ACD, SRHGVRAPHD) are extremely important for the varied catalytic activity during hydrolyzing phytate in the presence of humic acid (HA). However, little is known about the molecular-scale mechanisms of how HA influences the secondary structure of ACD found in phytase. First, in situ surface-enhanced Raman spectroscopy (SERS) results show the secondary structure transformation of ACD from the unordered random coil to the ordered β-sheet structure after treatment with HA. Then, we use an atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS) technique that can in situ directly probe the single-molecule interaction of ACD with HA and underlying changes in ACD secondary structure in the approach-retraction cycles in real time. Based on the SMFS results, we further detect the HA-enhanced formation of H-bonding between amide groups in the ACD backbone after noncovalently interacting with HA in the absence of phytate. Following the addition of phytate, the calculated contour length (Lc) and the free energies (ΔGb) of functional groups within ACD(-1/2) binding to mica/HA collectively demonstrate the formation of the organized intermediate structural state of ACD following its covalent binding to phytate. These spectroscopic and single-molecule determinations provide the molecular-scale understanding regarding the detailed mechanisms of HA-enhancement of the ordered β-sheet secondary structure of ACD through chemical functionalities in ACD noncovalently interacting with HA. Therefore, we suggest that similar studies of the interactions of other soil enzymes and plant nutrients may reveal predominant roles of dissolved organic matter (DOM) in controlling elemental cycling and fate for sustainable agriculture development.
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Affiliation(s)
- Xinfei Ge
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
| | - Wenjun Zhang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
| | - Christine V Putnis
- Institut für Mineralogie, University of Münster, 48149 Münster, Germany.,School of Molecular and Life Science, Curtin University, Perth 6845, Australia
| | - Lijun Wang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
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17
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Curtabbi A, Enríquez JA. The ins and outs of the flavin mononucleotide cofactor of respiratory complex I. IUBMB Life 2022; 74:629-644. [PMID: 35166025 DOI: 10.1002/iub.2600] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 01/23/2022] [Accepted: 01/24/2022] [Indexed: 12/12/2022]
Abstract
The flavin mononucleotide (FMN) cofactor of respiratory complex I occupies a key position in the electron transport chain. Here, the electrons coming from NADH start the sequence of oxidoreduction reactions, which drives the generation of the proton-motive force necessary for ATP synthesis. The overall architecture and the general catalytic proprieties of the FMN site are mostly well established. However, several aspects regarding the complex I flavin cofactor are still unknown. For example, the flavin binding to the N-module, the NADH-oxidizing portion of complex I, lacks a molecular description. The dissociation of FMN from the enzyme is beginning to emerge as an important regulatory mechanism of complex I activity and ROS production. Finally, how mitochondria import and metabolize FMN is still uncertain. This review summarizes the current knowledge on complex I flavin cofactor and discusses the open questions for future research.
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Affiliation(s)
- Andrea Curtabbi
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - José Antonio Enríquez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain.,Centro de Investigación Biomédica en Red en Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
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18
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Bustad HJ, Kallio JP, Vorland M, Fiorentino V, Sandberg S, Schmitt C, Aarsand AK, Martinez A. Acute Intermittent Porphyria: An Overview of Therapy Developments and Future Perspectives Focusing on Stabilisation of HMBS and Proteostasis Regulators. Int J Mol Sci 2021; 22:E675. [PMID: 33445488 PMCID: PMC7827610 DOI: 10.3390/ijms22020675] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 01/02/2021] [Accepted: 01/04/2021] [Indexed: 12/21/2022] Open
Abstract
Acute intermittent porphyria (AIP) is an autosomal dominant inherited disease with low clinical penetrance, caused by mutations in the hydroxymethylbilane synthase (HMBS) gene, which encodes the third enzyme in the haem biosynthesis pathway. In susceptible HMBS mutation carriers, triggering factors such as hormonal changes and commonly used drugs induce an overproduction and accumulation of toxic haem precursors in the liver. Clinically, this presents as acute attacks characterised by severe abdominal pain and a wide array of neurological and psychiatric symptoms, and, in the long-term setting, the development of primary liver cancer, hypertension and kidney failure. Treatment options are few, and therapies preventing the development of symptomatic disease and long-term complications are non-existent. Here, we provide an overview of the disorder and treatments already in use in clinical practice, in addition to other therapies under development or in the pipeline. We also introduce the pathomechanistic effects of HMBS mutations, and present and discuss emerging therapeutic options based on HMBS stabilisation and the regulation of proteostasis. These are novel mechanistic therapeutic approaches with the potential of prophylactic correction of the disease by totally or partially recovering the enzyme functionality. The present scenario appears promising for upcoming patient-tailored interventions in AIP.
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Affiliation(s)
- Helene J. Bustad
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway; (H.J.B.); (J.P.K.)
| | - Juha P. Kallio
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway; (H.J.B.); (J.P.K.)
| | - Marta Vorland
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, 5021 Bergen, Norway; (M.V.); (S.S.)
| | - Valeria Fiorentino
- INSERM U1149, Center for Research on Inflammation (CRI), Université de Paris, 75018 Paris, France; (V.F.); (C.S.)
| | - Sverre Sandberg
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, 5021 Bergen, Norway; (M.V.); (S.S.)
- Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus), Haraldsplass Deaconess Hospital, 5009 Bergen, Norway
| | - Caroline Schmitt
- INSERM U1149, Center for Research on Inflammation (CRI), Université de Paris, 75018 Paris, France; (V.F.); (C.S.)
- Assistance Publique Hôpitaux de Paris (AP-HP), Centre Français des Porphyries, Hôpital Louis Mourier, 92700 Colombes, France
| | - Aasne K. Aarsand
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, 5021 Bergen, Norway; (M.V.); (S.S.)
- Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus), Haraldsplass Deaconess Hospital, 5009 Bergen, Norway
| | - Aurora Martinez
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway; (H.J.B.); (J.P.K.)
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19
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Li J, Li H. Single molecule force spectroscopy reveals that a two-coordinate ferric site is critical for the folding of holo-rubredoxin. NANOSCALE 2020; 12:22564-22573. [PMID: 33169779 DOI: 10.1039/d0nr06275h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Metalloproteins play important roles in a wide range of biological processes. The folding process of metalloproteins is complex due to the synergistic effects of the folding of their polypeptide chains and the incorporation of metal cofactors. The folding mechanism of the simplest iron-sulfur protein rubredoxin, which contains one ferric ion coordinated by four cysteinyl sulfurs, is revealed using optical tweezers for the first time. The folding of the rubredoxin polypeptide chain is rapid and robust, while the reconstitution of the iron-sulfur center is greatly dependent upon the coordination state of the ferric ion on the unfolded polypeptide chain. If the ferric ion is coordinated by two neighboring cysteines, rubredoxin can readily fold with the iron-sulfur center fully reconstituted. However, if the ferric ion is only mono-coordinated, rubredoxin can fold but the iron-sulfur center is not reconstituted. Our results suggested that the folding of holo-rubredoxin follows a novel binding-folding-reconstitution mechanism, which is distinct from the folding mechanisms proposed for the folding of metalloproteins. Our study highlights the critical importance of the two-coordinate ferric site in the folding of holo-rubredoxin, which may have some important implications to our understanding of the folding mechanism of more complex metalloproteins in vivo.
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Affiliation(s)
- Jiayu Li
- Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada.
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20
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Substitution of the Native Zn(II) with Cd(II), Co(II) and Ni(II) Changes the Downhill Unfolding Mechanism of Ros87 to a Completely Different Scenario. Int J Mol Sci 2020; 21:ijms21218285. [PMID: 33167398 PMCID: PMC7663847 DOI: 10.3390/ijms21218285] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 10/30/2020] [Accepted: 11/03/2020] [Indexed: 12/15/2022] Open
Abstract
The structural effects of zinc replacement by xenobiotic metal ions have been widely studied in several eukaryotic and prokaryotic zinc-finger-containing proteins. The prokaryotic zinc finger, that presents a bigger βββαα domain with a larger hydrophobic core with respect to its eukaryotic counterpart, represents a valuable model protein to study metal ion interaction with metallo-proteins. Several studies have been conducted on Ros87, the DNA binding domain of the prokaryotic zinc finger Ros, and have demonstrated that the domain appears to structurally tolerate Ni(II), albeit with important structural perturbations, but not Pb(II) and Hg(II), and it is in vitro functional when the zinc ion is replaced by Cd(II). We have previously shown that Ros87 unfolding is a two-step process in which a zinc binding intermediate converts to the native structure thorough a delicate downhill folding transition. Here, we explore the folding/unfolding behaviour of Ros87 coordinated to Co(II), Ni(II) or Cd(II), by UV-Vis, CD, DSC and NMR techniques. Interestingly, we show how the substitution of the native metal ion results in complete different folding scenarios. We found a two-state unfolding mechanism for Cd-Ros87 whose metal affinity Kd is comparable to the one obtained for the native Zn-Ros87, and a more complex mechanism for Co-Ros87 and Ni-Ros87, that show higher Kd values. Our data outline the complex cross-correlation between the protein-metal ion equilibrium and the folding mechanism proposing such an interplay as a key factor in the proper metal ion selection by a specific metallo-protein.
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21
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Chen C, Park C. Chaperone action of a cofactor in protein folding. Protein Sci 2020; 29:1667-1678. [PMID: 32385904 DOI: 10.1002/pro.3880] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 05/03/2020] [Accepted: 05/05/2020] [Indexed: 11/11/2022]
Abstract
Previously, we have reported that ATP accelerates the folding and unfolding of Escherichia coli glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which is a glycolytic enzyme utilizing NAD+ as a cofactor. Because ATP and NAD+ share the ADP moiety, we hypothesized that NAD+ also accelerates the folding of GAPDH and that the common structural motif between ATP and NAD+ is responsible for the chaperone activity. After confirming that NAD+ indeed accelerates the folding of GAPDH, we examined the chaperone activity of the structural fragments of NAD+ (ADP, AMP, adenosine, and nicotinamide monophosphate). Our finding showed that ADP and AMP significantly speed up the folding of GAPDH, while adenosine and nicotinamide monophosphate do not. ADP and AMP also dramatically speed up the unfolding of GAPDH by selectively stabilizing a transition state in which GAPDH has a partially unfolded conformation. Similar to the previously reported effect of ATP on the equilibrium unfolding of GAPDH, a partially unfolded intermediate also accumulates in the presence of ADP and AMP. Based on the effect of the structural fragments of NAD+ on the folding of GAPDH, we identified that AMP is the structural determinant of the chaperone activity of ATP and NAD+ . Also, we propose a plausible model to explain how NAD+ accelerates the folding of GAPDH through a stepwise development of molecular interactions with the protein.
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Affiliation(s)
- Chen Chen
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, USA
| | - Chiwook Park
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, USA.,Interdisciplinary Life Science Graduate Program, Purdue University, West Lafayette, Indiana, USA.,Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, USA
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22
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Jeoung S, Shin S, Choi M. Copper-binding energetics of amicyanin in different folding states. Metallomics 2020; 12:273-279. [PMID: 31830170 DOI: 10.1039/c9mt00261h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Amicyanin is a type I copper protein that mediates electron transfer between methylamine dehydrogenase and cytochrome c-551i for energy production in Paracoccus denitrificans. Although the Met98 axial ligand of amicyanin has been shown to dictate metal selectivity and specificity during protein folding, the mechanism involved in copper-mediated amicyanin folding is unknown. Here, we kinetically and spectroscopically described reaction steps for incorporating copper into fully and less folded apo-amicyanin and established thermodynamic parameters for two amicyanin folding states. The rate constant for the incorporation of copper into fully folded apo-amicyanin at 25 °C was almost 1.5-fold lower than that for the initial phase of copper addition to the less folded apo-amicyanin. However, the rate constant was 10-fold higher than that of the second phase of copper addition to less folded apo-amicyanin at 25 °C. When overall binding energetic parameters (ΔH° and ΔS°) for the incorporation of copper into fully folded apo-amicyanin were measured by the van't Hoff method and isothermal titration calorimetry, the values were more positive than those determined for less folded apo-amicyanin. This indicates that during amicyanin biogenesis, copper rapidly binds to an unfolded apo-amicyanin active site, inducing protein folding and favorably influencing subsequent organization of copper ligands.
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Affiliation(s)
- Seounghun Jeoung
- Interdisciplinary Program of Bioenergy and Biomaterials Graduate School, College of Engineering, Chonnam National University, Gwangju 61186, Republic of Korea.
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23
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Paul BT, Tesfay L, Winkler CR, Torti FM, Torti SV. Sideroflexin 4 affects Fe-S cluster biogenesis, iron metabolism, mitochondrial respiration and heme biosynthetic enzymes. Sci Rep 2019; 9:19634. [PMID: 31873120 PMCID: PMC6928202 DOI: 10.1038/s41598-019-55907-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 12/03/2019] [Indexed: 12/12/2022] Open
Abstract
Sideroflexin4 (SFXN4) is a member of a family of nuclear-encoded mitochondrial proteins. Rare germline mutations in SFXN4 lead to phenotypic characteristics of mitochondrial disease including impaired mitochondrial respiration and hematopoetic abnormalities. We sought to explore the function of this protein. We show that knockout of SFXN4 has profound effects on Fe-S cluster formation. This in turn diminishes mitochondrial respiratory chain complexes and mitochondrial respiration and causes a shift to glycolytic metabolism. SFXN4 knockdown reduces the stability and activity of cellular Fe-S proteins, affects iron metabolism by influencing the cytosolic aconitase-IRP1 switch, redistributes iron from the cytosol to mitochondria, and impacts heme synthesis by reducing levels of ferrochelatase and inhibiting translation of ALAS2. We conclude that SFXN4 is essential for normal functioning of mitochondria, is necessary for Fe-S cluster biogenesis and iron homeostasis, and plays a critical role in mitochondrial respiration and synthesis of heme.
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Affiliation(s)
- Bibbin T Paul
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, 06030, USA
| | - Lia Tesfay
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, 06030, USA
| | - C R Winkler
- Institute for Critical Technology and Applied Science, Nanoscale Characterization and Fabrication Laboratory, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Frank M Torti
- Department of Medicine, University of Connecticut Health Center, Farmington, CT, 06030, USA
| | - Suzy V Torti
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, 06030, USA.
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24
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Abstract
Copper is a redox-active transition metal ion required for the function of many essential human proteins. For biosynthesis of proteins coordinating copper, the metal may bind before, during or after folding of the polypeptide. If the metal binds to unfolded or partially folded structures of the protein, such coordination may modulate the folding reaction. The molecular understanding of how copper is incorporated into proteins requires descriptions of chemical, thermodynamic, kinetic and structural parameters involved in the formation of protein-metal complexes. Because free copper ions are toxic, living systems have elaborate copper-transport systems that include particular proteins that facilitate efficient and specific delivery of copper ions to target proteins. Therefore, these pathways become an integral part of copper protein folding in vivo. This review summarizes biophysical-molecular in vitro work assessing the role of copper in folding and stability of copper-binding proteins as well as protein-protein copper exchange reactions between human copper transport proteins. We also describe some recent findings about the participation of copper ions and copper proteins in protein misfolding and aggregation reactions in vitro.
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25
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Zhang J, Tang T, Jiang Z, Liu Y, Jiang A. The modification of ovalbumin surface properties treated by pulsed electric field combined with divalent metal ions. Food Chem 2019; 293:455-462. [DOI: 10.1016/j.foodchem.2019.05.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 04/15/2019] [Accepted: 05/02/2019] [Indexed: 11/25/2022]
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26
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Harischandra DS, Ghaisas S, Zenitsky G, Jin H, Kanthasamy A, Anantharam V, Kanthasamy AG. Manganese-Induced Neurotoxicity: New Insights Into the Triad of Protein Misfolding, Mitochondrial Impairment, and Neuroinflammation. Front Neurosci 2019; 13:654. [PMID: 31293375 PMCID: PMC6606738 DOI: 10.3389/fnins.2019.00654] [Citation(s) in RCA: 156] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 06/06/2019] [Indexed: 12/21/2022] Open
Abstract
Occupational or environmental exposure to manganese (Mn) can lead to the development of "Manganism," a neurological condition showing certain motor symptoms similar to Parkinson's disease (PD). Like PD, Mn toxicity is seen in the central nervous system mainly affecting nigrostriatal neuronal circuitry and subsequent behavioral and motor impairments. Since the first report of Mn-induced toxicity in 1837, various experimental and epidemiological studies have been conducted to understand this disorder. While early investigations focused on the impact of high concentrations of Mn on the mitochondria and subsequent oxidative stress, current studies have attempted to elucidate the cellular and molecular pathways involved in Mn toxicity. In fact, recent reports suggest the involvement of Mn in the misfolding of proteins such as α-synuclein and amyloid, thus providing credence to the theory that environmental exposure to toxicants can either initiate or propagate neurodegenerative processes by interfering with disease-specific proteins. Besides manganism and PD, Mn has also been implicated in other neurological diseases such as Huntington's and prion diseases. While many reviews have focused on Mn homeostasis, the aim of this review is to concisely synthesize what we know about its effect primarily on the nervous system with respect to its role in protein misfolding, mitochondrial dysfunction, and consequently, neuroinflammation and neurodegeneration. Based on the current evidence, we propose a 'Mn Mechanistic Neurotoxic Triad' comprising (1) mitochondrial dysfunction and oxidative stress, (2) protein trafficking and misfolding, and (3) neuroinflammation.
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Affiliation(s)
- Dilshan S Harischandra
- Department of Biomedical Sciences, Parkinson's Disorder Research Laboratory, Iowa State University, Ames, IA, United States
| | - Shivani Ghaisas
- Department of Biomedical Sciences, Parkinson's Disorder Research Laboratory, Iowa State University, Ames, IA, United States
| | - Gary Zenitsky
- Department of Biomedical Sciences, Parkinson's Disorder Research Laboratory, Iowa State University, Ames, IA, United States
| | - Huajun Jin
- Department of Biomedical Sciences, Parkinson's Disorder Research Laboratory, Iowa State University, Ames, IA, United States
| | - Arthi Kanthasamy
- Department of Biomedical Sciences, Parkinson's Disorder Research Laboratory, Iowa State University, Ames, IA, United States
| | - Vellareddy Anantharam
- Department of Biomedical Sciences, Parkinson's Disorder Research Laboratory, Iowa State University, Ames, IA, United States
| | - Anumantha G Kanthasamy
- Department of Biomedical Sciences, Parkinson's Disorder Research Laboratory, Iowa State University, Ames, IA, United States
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27
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Domanska B, Fortea E, West MJ, Schwartz JL, Crickmore N. The role of membrane-bound metal ions in toxicity of a human cancer cell-active pore-forming toxin Cry41Aa from Bacillus thuringiensis. Toxicon 2019; 167:123-133. [PMID: 31181295 DOI: 10.1016/j.toxicon.2019.06.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/09/2019] [Accepted: 06/03/2019] [Indexed: 12/30/2022]
Abstract
Bacillus thuringiensis crystal (Cry) proteins, used for decades as insecticidal toxins, are well known to be toxic to certain insects, but not to mammals. A novel group of Cry toxins called parasporins possess a strong cytocidal activity against some human cancer cells. Cry41Aa, or parasporin3, closely resembles commercially used insecticidal toxins and yet is toxic to the human hepatic cancer cell line HepG2, disrupting membranes of susceptible cells, similar to its insecticidal counterparts. In this study, we explore the protective effect that the common divalent metal chelator EGTA exerts on Cry41Aa's activity on HepG2 cells. Our results indicate that rather than interfering with a signalling pathway as a result of chelating cations in the medium, the chelator prevented the toxin's interaction with the membrane, and thus the subsequent steps of membrane damage and p38 phosphorylation, by removing cations bound to plasma membrane components. BAPTA and DTPA also inhibited Cry41Aa toxicity but at higher concentrations. We also show for the first time that Cry41Aa induces pore formation in planar lipid bilayers. This activity is not altered by EGTA, consistent with a biological context of chelation. Salt supplementation assays identified Ca2+, Mn2+ and Zn2+ as being able to reinstate Cry41Aa activity. Our data suggest the existence of one or more metal cation-dependent receptors in the Cry41Aa mechanism of action.
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Affiliation(s)
- Barbara Domanska
- School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK.
| | - Eva Fortea
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Québec, H3C 3J7, Canada; Cornell Graduate School of Medical Sciences, 1300 York Avenue, New York, NY, 10065, USA
| | - Michelle J West
- School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| | - Jean-Louis Schwartz
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Québec, H3C 3J7, Canada
| | - Neil Crickmore
- School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
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28
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Gold‐Ions‐Mediated Diproline Peptide Nanocarpets and Their Inhibition of Bacterial Growth. ChemistrySelect 2019. [DOI: 10.1002/slct.201900847] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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29
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Abstract
Zinc ion binding is a principal event in the achievement of the correct fold in classical zinc finger domains since the motif is largely unfolded in the absence of metal. In the case of a prokaryotic zinc finger, the larger βββαα domain contributes to the folding mechanism with a larger hydrophobic core. For these reasons, following the great amount of attention devoted to unveiling the effect of xenobiotic metal ion replacement in zinc fingers and in zinc-containing proteins in general, the prokaryotic zinc finger domain appears to be an interesting model for studying metal ion interaction with metalloproteins. Here, we explore the binding of Ni(II), Hg(II), and Pb(II) to Ros87, the DNA binding domain of the prokaryotic zinc finger protein Ros. We measured Ros87-metal ion dissociation constants and monitored the effects on the structure and function of the domain. Interestingly, we found that the protein folds in the presence of Ni(II) with important structural perturbations, while in the presence of Pb(II) and Hg(II) it does not appear to be significantly folded. Accordingly, an overall strong reduction in the DNA binding capability is observed for all of the examined proteins. Our data integrate and complement the information collected in the past few years concerning the functional and structural effects of metal ion substitution in classical zinc fingers in order to contribute to a better comprehension of the toxicity of these metals in biological systems.
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30
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Li J, Li H. Mechanical Unfolding Pathway of the High-Potential Iron-Sulfur Protein Revealed by Single-Molecule Atomic Force Microscopy: Toward a General Unfolding Mechanism for Iron-sulfur Proteins. J Phys Chem B 2018; 122:9340-9349. [PMID: 30212202 DOI: 10.1021/acs.jpcb.8b07614] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
High-potential iron-sulfur proteins (HiPIPs) are an important class of metalloproteins with a [4Fe-4S] cluster coordinated by four cysteine residues. Distinct from other iron-sulfur proteins, the cluster in HiPIP has a high reduction potential, making it an essential electron carrier in bacterial photosynthesis. Here, we combined single-molecule atomic force microscopy and protein engineering techniques to investigate the mechanical unfolding mechanism of HiPIP from Chromatium tepidum (cHiPIP). We found that cHiPIP unfolds in a two-step fashion with the protein sequence sequestered by the iron-sulfur center as a stable unfolding intermediate state. The rupture of the iron-sulfur center of cHiPIP proceeds in two distinct parallel pathways; one pathway involves the concurrent rupture of multiple iron-thiolate bonds, and the other one involves the sequential rupture of the iron-thiolate bonds. This mechanistic information was further confirmed by mutational studies. We found that the rupture of the iron-thiolate bonds in reduced and oxidized cHiPIP occurred in the range of 150-180 pN at a pulling speed of 400 nm/s, similar to that measured for iron-thiolate bonds in rubredoxin and ferredoxin. Our results may have important implications for understanding the general unfolding mechanism governing iron-sulfur proteins, as well as the mechanism governing the mechanical rupture of the iron-sulfur center.
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Affiliation(s)
- Jiayu Li
- Department of Chemistry , University of British Columbia , Vancouver , British Columbia V6T 1Z1 , Canada
| | - Hongbin Li
- Department of Chemistry , University of British Columbia , Vancouver , British Columbia V6T 1Z1 , Canada
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31
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Chen S, Campillo-Brocal JC, Berglund P, Humble MS. Characterization of the stability of Vibrio fluvialis JS17 amine transaminase. J Biotechnol 2018; 282:10-17. [PMID: 29906477 DOI: 10.1016/j.jbiotec.2018.06.309] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 06/01/2018] [Accepted: 06/07/2018] [Indexed: 10/14/2022]
Abstract
The amine transaminase from Vibrio fluvialis (Vf-ATA) is an attractive enzyme with applications within Biocatalysis for the preparation of chiral amines. Various catalytic properties of Vf-ATA have been investigated, but a biophysical characterization of its stability has been lacking. Today, the industrial application of Vf-ATA is limited by its low operational stability. In order to enhance the knowledge regarding the structural stability of ATAs, general characterizations of different ATAs are required. In this work, the stability of Vf-ATA was explored. First, the affinity between enzyme and pyridoxal-5'-phosphate (PLP) (KD value of 7.9 μM) was determined. Addition of PLP to enzyme preparations significantly improved the enzyme thermal stability by preventing enzyme unfolding. With the aim to understand if this was due to the PLP phosphate group coordination into the phosphate group binding cup, the effect of phosphate buffer on the enzyme stability was compared to HEPES buffer. Low concentrations of phosphate buffer showed a positive effect on the enzyme initial activity, while higher phosphate buffer concentrations prevented cofactor dissociation. Additionally, the effects of various amine or ketone substrates on the enzyme stability were explored. All tested amines caused a concentration dependent enzyme inactivation, while the corresponding ketones showed no or stabilizing effects. The enzyme inactivation due to the presence of amine can be connected to the formation of PMP, which forms in the presence of amines in the absence of ketone. Since PMP is not covalently bound to the enzyme, it could readily leave the enzyme upon formation. Exploring the different stability effects of cofactor, substrates, additives and buffer system on ATAs seems to be important in order to understand and improve the general performance of ATAs.
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Affiliation(s)
- Shan Chen
- KTH Royal Institute of Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Department of Industrial Biotechnology, AlbaNova University Center, SE-106 91, Stockholm, Sweden
| | - Jonatan C Campillo-Brocal
- KTH Royal Institute of Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Department of Industrial Biotechnology, AlbaNova University Center, SE-106 91, Stockholm, Sweden
| | - Per Berglund
- KTH Royal Institute of Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Department of Industrial Biotechnology, AlbaNova University Center, SE-106 91, Stockholm, Sweden
| | - Maria Svedendahl Humble
- KTH Royal Institute of Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Department of Industrial Biotechnology, AlbaNova University Center, SE-106 91, Stockholm, Sweden; Pharem Biotech AB, Biovation Park, Forskargatan 20 J, SE-151 36, Södertälje, Sweden.
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32
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Hoffmann B, Löhr F, Laguerre A, Bernhard F, Dötsch V. Protein labeling strategies for liquid-state NMR spectroscopy using cell-free synthesis. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2018; 105:1-22. [PMID: 29548364 DOI: 10.1016/j.pnmrs.2017.11.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 11/16/2017] [Indexed: 05/17/2023]
Abstract
Preparation of a protein sample for liquid-state nuclear magnetic resonance (NMR) spectroscopy analysis requires optimization of many parameters. This review describes labeling strategies for obtaining assignments of protein resonances. Particular emphasis is placed on the advantages of cell-free protein production, which enables exclusive labeling of the protein of interest, thereby simplifying downstream processing steps and increasing the availability of different labeling strategies for a target protein. Furthermore, proteins can be synthesized in milligram yields, and the open nature of the cell-free system allows the addition of stabilizers, scrambling inhibitors or hydrophobic solubilization environments directly during the protein synthesis, which is especially beneficial for membrane proteins. Selective amino acid labeling of the protein of interest, the possibility of addressing scrambling issues and avoiding the need for labile amino acid precursors have been key factors in enabling the introduction of new assignment strategies based on different labeling schemes as well as on new pulse sequences. Combinatorial selective labeling methods have been developed to reduce the number of protein samples necessary to achieve a complete backbone assignment. Furthermore, selective labeling helps to decrease spectral overlap and overcome size limitations for solution NMR analysis of larger complexes, oligomers, intrinsically disordered proteins and membrane proteins.
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Affiliation(s)
- Beate Hoffmann
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max-von-Laue Str. 9, 60438 Frankfurt, Germany
| | - Frank Löhr
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max-von-Laue Str. 9, 60438 Frankfurt, Germany
| | - Aisha Laguerre
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max-von-Laue Str. 9, 60438 Frankfurt, Germany
| | - Frank Bernhard
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max-von-Laue Str. 9, 60438 Frankfurt, Germany
| | - Volker Dötsch
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max-von-Laue Str. 9, 60438 Frankfurt, Germany.
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33
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Malla S, Gummadi SN. Thermal stability of xylose reductase from Debaryomyces nepalensis NCYC 3413: deactivation kinetics and structural studies. Process Biochem 2018. [DOI: 10.1016/j.procbio.2018.01.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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34
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Arai M. Unified understanding of folding and binding mechanisms of globular and intrinsically disordered proteins. Biophys Rev 2018; 10:163-181. [PMID: 29307002 PMCID: PMC5899706 DOI: 10.1007/s12551-017-0346-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 11/13/2017] [Indexed: 12/18/2022] Open
Abstract
Extensive experimental and theoretical studies have advanced our understanding of the mechanisms of folding and binding of globular proteins, and coupled folding and binding of intrinsically disordered proteins (IDPs). The forces responsible for conformational changes and binding are common in both proteins; however, these mechanisms have been separately discussed. Here, we attempt to integrate the mechanisms of coupled folding and binding of IDPs, folding of small and multi-subdomain proteins, folding of multimeric proteins, and ligand binding of globular proteins in terms of conformational selection and induced-fit mechanisms as well as the nucleation–condensation mechanism that is intermediate between them. Accumulating evidence has shown that both the rate of conformational change and apparent rate of binding between interacting elements can determine reaction mechanisms. Coupled folding and binding of IDPs occurs mainly by induced-fit because of the slow folding in the free form, while ligand binding of globular proteins occurs mainly by conformational selection because of rapid conformational change. Protein folding can be regarded as the binding of intramolecular segments accompanied by secondary structure formation. Multi-subdomain proteins fold mainly by the induced-fit (hydrophobic collapse) mechanism, as the connection of interacting segments enhances the binding (compaction) rate. Fewer hydrophobic residues in small proteins reduce the intramolecular binding rate, resulting in the nucleation–condensation mechanism. Thus, the folding and binding of globular proteins and IDPs obey the same general principle, suggesting that the coarse-grained, statistical mechanical model of protein folding is promising for a unified theoretical description of all mechanisms.
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Affiliation(s)
- Munehito Arai
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo, 153-8902, Japan.
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35
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The soluble loop BC region guides, but not dictates, the assembly of the transmembrane cytochrome b6. PLoS One 2017; 12:e0189532. [PMID: 29240839 PMCID: PMC5730185 DOI: 10.1371/journal.pone.0189532] [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: 07/06/2017] [Accepted: 11/27/2017] [Indexed: 11/19/2022] Open
Abstract
Studying folding and assembly of naturally occurring α-helical transmembrane proteins can inspire the design of membrane proteins with defined functions. Thus far, most studies have focused on the role of membrane-integrated protein regions. However, to fully understand folding pathways and stabilization of α–helical membrane proteins, it is vital to also include the role of soluble loops. We have analyzed the impact of interhelical loops on folding, assembly and stability of the heme-containing four-helix bundle transmembrane protein cytochrome b6 that is involved in charge transfer across biomembranes. Cytochrome b6 consists of two transmembrane helical hairpins that sandwich two heme molecules. Our analyses strongly suggest that the loop connecting the helical hairpins is not crucial for positioning the two protein “halves” for proper folding and assembly of the holo-protein. Furthermore, proteolytic removal of any of the remaining two loops, which connect the two transmembrane helices of a hairpin structure, appears to also not crucially effect folding and assembly. Overall, the transmembrane four-helix bundle appears to be mainly stabilized via interhelical interactions in the transmembrane regions, while the soluble loop regions guide assembly and stabilize the holo-protein. The results of this study might steer future strategies aiming at designing heme-binding four-helix bundle structures, involved in transmembrane charge transfer reactions.
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36
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37
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Mushtaq AU, Park JS, Bae SH, Kim HY, Yeo KJ, Hwang E, Lee KY, Jee JG, Cheong HK, Jeon YH. Ligand-Mediated Folding of the OmpA Periplasmic Domain from Acinetobacter baumannii. Biophys J 2017; 112:2089-2098. [PMID: 28538146 DOI: 10.1016/j.bpj.2017.04.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 03/10/2017] [Accepted: 04/13/2017] [Indexed: 11/27/2022] Open
Abstract
The periplasmic domain of OmpA from Acinetobacter baumannii (AbOmpA-PD) binds to diaminopimelate and anchors the outer membrane to the peptidoglycan layer in the cell wall. Although the crystal structure of AbOmpA-PD with its ligands has been reported, the mechanism of ligand-mediated folding of AbOmpA remains elusive. Here, we report that in vitro refolded apo-AbOmpA-PD in the absence of ligand exists as a mixture of two partially folded forms in solution: mostly unfolded (apo-state I) and hololike (apo-state II) states. Binding of the diaminopimelate or glycine ligand induced complete folding of AbOmpA-PD. The apo-state I was highly flexible and contained some secondary structural elements, whereas the apo-state II closely resembled the holo-state in terms of both structure and backbone dynamics, except for the ligand-binding region. 15N-relaxation-dispersion analyses for apo-state II revealed substantial motion on a millisecond timescale of residues in the H3 helix near the ligand-binding site, with this motion disappearing upon ligand binding. These results provide an insight into the ligand-mediated folding mechanism of AbOmpA-PD in solution.
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Affiliation(s)
- Ameeq Ul Mushtaq
- College of Pharmacy, Korea University, Sejong-ro, Sejong, Republic of Korea
| | - Jeong Soon Park
- Division of Bioconvergence Analysis, Korea Basic Science Institute, Ochang, Chungbuk, Republic of Korea; CKD Research Institute, Giheung-gu, Yongin-si, Gyeonggi-do, Republic of Korea; College of Pharmacy, Kyungpook National University, Buk-gu, Daegu, Republic of Korea
| | - Sung-Hun Bae
- CKD Research Institute, Giheung-gu, Yongin-si, Gyeonggi-do, Republic of Korea
| | - Hye-Yeon Kim
- Division of Bioconvergence Analysis, Korea Basic Science Institute, Ochang, Chungbuk, Republic of Korea; Center for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, Daejeon, South Korea
| | - Kwon Joo Yeo
- College of Pharmacy, Korea University, Sejong-ro, Sejong, Republic of Korea; Division of Bioconvergence Analysis, Korea Basic Science Institute, Ochang, Chungbuk, Republic of Korea
| | - Eunha Hwang
- Division of Bioconvergence Analysis, Korea Basic Science Institute, Ochang, Chungbuk, Republic of Korea
| | - Ki Yong Lee
- College of Pharmacy, Korea University, Sejong-ro, Sejong, Republic of Korea
| | - Jun-Goo Jee
- College of Pharmacy, Kyungpook National University, Buk-gu, Daegu, Republic of Korea
| | - Hae-Kap Cheong
- Division of Bioconvergence Analysis, Korea Basic Science Institute, Ochang, Chungbuk, Republic of Korea.
| | - Young Ho Jeon
- College of Pharmacy, Korea University, Sejong-ro, Sejong, Republic of Korea.
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38
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Yamaguchi T, Nihei Y, Sutherland DEK, Stillman MJ, Kohzuma T. Stabilization of protein structure through π-π interaction in the second coordination sphere of pseudoazurin. Protein Sci 2017; 26:1921-1931. [PMID: 28691165 DOI: 10.1002/pro.3226] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 07/01/2017] [Accepted: 07/04/2017] [Indexed: 11/11/2022]
Abstract
Noncovalent, weak interactions in the second coordination sphere of the copper active site of Pseudoazurin (PAz) from Achromobacter cycloclastes were examined using a series of Met16X variants. In this study, the differences in protein stability due to the changes in the nature of the 16th amino acid (Met, Phe, Val, Ile) were investigated by electrospray ionization mass spectrometry (ESI-MS) and far-UV circular dichroism (CD) as a result of acid denaturation. The percentage of native states (folded holo forms) of Met16Phe variants was estimated to be 75% at pH 2.9 although the wild-type (WT), Met16Val and Met16Ile PAz, became completely unfolded. The high stability under acidic conditions is correlated with the result of the active site being stabilized by the aromatic substitution of the Met16 residue. The π-π interaction in the second coordination sphere makes a significant contribution to the stability of active site and the protein matrix.
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Affiliation(s)
- Takahide Yamaguchi
- Graduate School of Science and Engineering, Institute of Quantum Beam Science, Ibaraki University, Mito, Ibaraki, 310-8512, Japan
| | - Yuko Nihei
- Graduate School of Science and Engineering, Institute of Quantum Beam Science, Ibaraki University, Mito, Ibaraki, 310-8512, Japan
| | - Duncan E K Sutherland
- Department of Biology, The University of Western Ontario, London, Ontario, Canada.,Department of Chemistry, The University of Western Ontario, London, Ontario, Canada
| | - Martin J Stillman
- Department of Biology, The University of Western Ontario, London, Ontario, Canada.,Department of Chemistry, The University of Western Ontario, London, Ontario, Canada
| | - Takamitsu Kohzuma
- Graduate School of Science and Engineering, Institute of Quantum Beam Science, Ibaraki University, Mito, Ibaraki, 310-8512, Japan
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39
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Lei H, Guo Y, Hu X, Hu C, Hu X, Li H. Reversible Unfolding and Folding of the Metalloprotein Ferredoxin Revealed by Single-Molecule Atomic Force Microscopy. J Am Chem Soc 2017; 139:1538-1544. [DOI: 10.1021/jacs.6b11371] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hai Lei
- State
Key Laboratory of Precision Measurements Technology and Instruments,
School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, People’s Republic of China
- Department
of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Yabin Guo
- Department
of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Xiaodong Hu
- State
Key Laboratory of Precision Measurements Technology and Instruments,
School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Chunguang Hu
- State
Key Laboratory of Precision Measurements Technology and Instruments,
School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Xiaotang Hu
- State
Key Laboratory of Precision Measurements Technology and Instruments,
School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, People’s Republic of China
| | - Hongbin Li
- State
Key Laboratory of Precision Measurements Technology and Instruments,
School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, People’s Republic of China
- Department
of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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40
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Amyloid-like aggregates formation by bovine apo-carbonic anhydrase in various alcohols: A comparative study. Int J Biol Macromol 2016; 92:573-580. [DOI: 10.1016/j.ijbiomac.2016.07.083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 07/11/2016] [Accepted: 07/24/2016] [Indexed: 12/31/2022]
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41
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Churchfield LA, Medina-Morales A, Brodin JD, Perez A, Tezcan FA. De Novo Design of an Allosteric Metalloprotein Assembly with Strained Disulfide Bonds. J Am Chem Soc 2016; 138:13163-13166. [PMID: 27649076 DOI: 10.1021/jacs.6b08458] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A major goal in metalloprotein design is to build protein scaffolds from scratch that allow precise control over metal coordination. A particular challenge in this regard is the construction of allosteric systems in which metal coordination equilibria are coupled to other chemical events that take place elsewhere in the protein scaffold. We previously developed a metal-templated self-assembly strategy (MeTIR) to build supramolecular protein complexes with tailorable interfaces from monomeric building blocks. Here, using this strategy, we have incorporated multiple disulfide bonds into the interfaces of a Zn-templated cytochrome cb562 assembly in order to create mechanical strain on the quaternary structural level. Structural and biophysical analyses indicate that this strain leads to an allosteric system in which Zn2+ binding and dissociation are remotely coupled to the formation and breakage of a disulfide bond over a distance of >14 Å. The breakage of this strained bond upon Zn2+ dissociation occurs in the absence of any reductants, apparently through a hydrolytic mechanism that generates a sulfenic acid/thiol pair.
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Affiliation(s)
- Lewis A Churchfield
- Department of Chemistry and Biochemistry, University of California, San Diego , La Jolla, California 92093-0356, United States
| | - Annette Medina-Morales
- Department of Chemistry and Biochemistry, University of California, San Diego , La Jolla, California 92093-0356, United States
| | - Jeffrey D Brodin
- Department of Chemistry and Biochemistry, University of California, San Diego , La Jolla, California 92093-0356, United States
| | - Alfredo Perez
- Department of Chemistry and Biochemistry, University of California, San Diego , La Jolla, California 92093-0356, United States
| | - F Akif Tezcan
- Department of Chemistry and Biochemistry, University of California, San Diego , La Jolla, California 92093-0356, United States
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42
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De Geyter J, Tsirigotaki A, Orfanoudaki G, Zorzini V, Economou A, Karamanou S. Protein folding in the cell envelope of Escherichia coli. Nat Microbiol 2016; 1:16107. [PMID: 27573113 DOI: 10.1038/nmicrobiol.2016.107] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 06/02/2016] [Indexed: 11/09/2022]
Abstract
While the entire proteome is synthesized on cytoplasmic ribosomes, almost half associates with, localizes in or crosses the bacterial cell envelope. In Escherichia coli a variety of mechanisms are important for taking these polypeptides into or across the plasma membrane, maintaining them in soluble form, trafficking them to their correct cell envelope locations and then folding them into the right structures. The fidelity of these processes must be maintained under various environmental conditions including during stress; if this fails, proteases are called in to degrade mislocalized or aggregated proteins. Various soluble, diffusible chaperones (acting as holdases, foldases or pilotins) and folding catalysts are also utilized to restore proteostasis. These responses can be general, dealing with multiple polypeptides, with functional overlaps and operating within redundant networks. Other chaperones are specialized factors, dealing only with a few exported proteins. Several complex machineries have evolved to deal with binding to, integration in and crossing of the outer membrane. This complex protein network is responsible for fundamental cellular processes such as cell wall biogenesis; cell division; the export, uptake and degradation of molecules; and resistance against exogenous toxic factors. The underlying processes, contributing to our fundamental understanding of proteostasis, are a treasure trove for the development of novel antibiotics, biopharmaceuticals and vaccines.
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Affiliation(s)
- Jozefien De Geyter
- KU Leuven-University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Molecular Bacteriology, B-3000 Leuven, Belgium
| | - Alexandra Tsirigotaki
- KU Leuven-University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Molecular Bacteriology, B-3000 Leuven, Belgium
| | - Georgia Orfanoudaki
- Institute of Molecular Biology and Biotechnology, FORTH and Department of Biology, University of Crete, PO Box 1385, GR-711 10 Iraklio, Crete, Greece
| | - Valentina Zorzini
- KU Leuven-University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Molecular Bacteriology, B-3000 Leuven, Belgium
| | - Anastassios Economou
- KU Leuven-University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Molecular Bacteriology, B-3000 Leuven, Belgium.,Institute of Molecular Biology and Biotechnology, FORTH and Department of Biology, University of Crete, PO Box 1385, GR-711 10 Iraklio, Crete, Greece
| | - Spyridoula Karamanou
- KU Leuven-University of Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Molecular Bacteriology, B-3000 Leuven, Belgium
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43
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Affiliation(s)
- Pernilla Wittung-Stafshede
- Department of Biology and Biological Engineering; Chalmers University of Technology; 41296 Gothenburg Sweden
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44
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Montagner C, Nigen M, Jacquin O, Willet N, Dumoulin M, Karsisiotis AI, Roberts GCK, Damblon C, Redfield C, Matagne A. The Role of Active Site Flexible Loops in Catalysis and of Zinc in Conformational Stability of Bacillus cereus 569/H/9 β-Lactamase. J Biol Chem 2016; 291:16124-37. [PMID: 27235401 DOI: 10.1074/jbc.m116.719005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Indexed: 11/06/2022] Open
Abstract
Metallo-β-lactamases catalyze the hydrolysis of most β-lactam antibiotics and hence represent a major clinical concern. The development of inhibitors for these enzymes is complicated by the diversity and flexibility of their substrate-binding sites, motivating research into their structure and function. In this study, we examined the conformational properties of the Bacillus cereus β-lactamase II in the presence of chemical denaturants using a variety of biochemical and biophysical techniques. The apoenzyme was found to unfold cooperatively, with a Gibbs free energy of stabilization (ΔG(0)) of 32 ± 2 kJ·mol(-1) For holoBcII, a first non-cooperative transition leads to multiple interconverting native-like states, in which both zinc atoms remain bound in an apparently unaltered active site, and the protein displays a well organized compact hydrophobic core with structural changes confined to the enzyme surface, but with no catalytic activity. Two-dimensional NMR data revealed that the loss of activity occurs concomitantly with perturbations in two loops that border the enzyme active site. A second cooperative transition, corresponding to global unfolding, is observed at higher denaturant concentrations, with ΔG(0) value of 65 ± 1.4 kJ·mol(-1) These combined data highlight the importance of the two zinc ions in maintaining structure as well as a relatively well defined conformation for both active site loops to maintain enzymatic activity.
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Affiliation(s)
- Caroline Montagner
- From the Laboratoire d'Enzymologie et Repliement des Protéines, Centre d'Ingénierie des Protéines, and
| | - Michaël Nigen
- From the Laboratoire d'Enzymologie et Repliement des Protéines, Centre d'Ingénierie des Protéines, and
| | - Olivier Jacquin
- From the Laboratoire d'Enzymologie et Repliement des Protéines, Centre d'Ingénierie des Protéines, and
| | - Nicolas Willet
- From the Laboratoire d'Enzymologie et Repliement des Protéines, Centre d'Ingénierie des Protéines, and
| | - Mireille Dumoulin
- From the Laboratoire d'Enzymologie et Repliement des Protéines, Centre d'Ingénierie des Protéines, and
| | - Andreas Ioannis Karsisiotis
- the School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, United Kingdom
| | - Gordon C K Roberts
- the Henry Wellcome Laboratories of Structural Biology, Department of Biochemistry, University of Leicester, Leicester LE1 9HN, United Kingdom, and
| | - Christian Damblon
- Département de Chimie, Université de Liège, Institut de Chimie B6, 4000 Liège (Sart Tilman), Belgium
| | - Christina Redfield
- the Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - André Matagne
- From the Laboratoire d'Enzymologie et Repliement des Protéines, Centre d'Ingénierie des Protéines, and
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45
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Designed protein reveals structural determinants of extreme kinetic stability. Proc Natl Acad Sci U S A 2015; 112:14605-10. [PMID: 26554002 DOI: 10.1073/pnas.1510748112] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The design of stable, functional proteins is difficult. Improved design requires a deeper knowledge of the molecular basis for design outcomes and properties. We previously used a bioinformatics and energy function method to design a symmetric superfold protein composed of repeating structural elements with multivalent carbohydrate-binding function, called ThreeFoil. This and similar methods have produced a notably high yield of stable proteins. Using a battery of experimental and computational analyses we show that despite its small size and lack of disulfide bonds, ThreeFoil has remarkably high kinetic stability and its folding is specifically chaperoned by carbohydrate binding. It is also extremely stable against thermal and chemical denaturation and proteolytic degradation. We demonstrate that the kinetic stability can be predicted and modeled using absolute contact order (ACO) and long-range order (LRO), as well as coarse-grained simulations; the stability arises from a topology that includes many long-range contacts which create a large and highly cooperative energy barrier for unfolding and folding. Extensive data from proteomic screens and other experiments reveal that a high ACO/LRO is a general feature of proteins with strong resistances to denaturation and degradation. These results provide tractable approaches for predicting resistance and designing proteins with sufficient topological complexity and long-range interactions to accommodate destabilizing functional features as well as withstand chemical and proteolytic challenge.
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Giannotti MI, Cabeza de Vaca I, Artés JM, Sanz F, Guallar V, Gorostiza P. Direct Measurement of the Nanomechanical Stability of a Redox Protein Active Site and Its Dependence upon Metal Binding. J Phys Chem B 2015; 119:12050-8. [DOI: 10.1021/acs.jpcb.5b06382] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marina I. Giannotti
- Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid 28029, Spain
- Physical
Chemistry Department, Universitat de Barcelona, Barcelona 08028, Spain
- Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 15-21, Barcelona 08028, Spain
| | - Israel Cabeza de Vaca
- Joint
BSC-CRG-IRB Research Program in Computational Biology, Barcelona Supercomputing Center, Jordi Girona 29, Barcelona 08034, Spain
| | - Juan M. Artés
- Physical
Chemistry Department, Universitat de Barcelona, Barcelona 08028, Spain
- Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 15-21, Barcelona 08028, Spain
| | - Fausto Sanz
- Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid 28029, Spain
- Physical
Chemistry Department, Universitat de Barcelona, Barcelona 08028, Spain
- Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 15-21, Barcelona 08028, Spain
| | - Victor Guallar
- Joint
BSC-CRG-IRB Research Program in Computational Biology, Barcelona Supercomputing Center, Jordi Girona 29, Barcelona 08034, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona 08010, Spain
| | - Pau Gorostiza
- Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid 28029, Spain
- Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 15-21, Barcelona 08028, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona 08010, Spain
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Roccatano D. Structure, dynamics, and function of the monooxygenase P450 BM-3: insights from computer simulations studies. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:273102. [PMID: 26061496 DOI: 10.1088/0953-8984/27/27/273102] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The monooxygenase P450 BM-3 is a NADPH-dependent fatty acid hydroxylase enzyme isolated from soil bacterium Bacillus megaterium. As a pivotal member of cytochrome P450 superfamily, it has been intensely studied for the comprehension of structure-dynamics-function relationships in this class of enzymes. In addition, due to its peculiar properties, it is also a promising enzyme for biochemical and biomedical applications. However, despite the efforts, the full understanding of the enzyme structure and dynamics is not yet achieved. Computational studies, particularly molecular dynamics (MD) simulations, have importantly contributed to this endeavor by providing new insights at an atomic level regarding the correlations between structure, dynamics, and function of the protein. This topical review summarizes computational studies based on MD simulations of the cytochrome P450 BM-3 and gives an outlook on future directions.
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Affiliation(s)
- Danilo Roccatano
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany
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Hamdane D, Bou-Nader C, Cornu D, Hui-Bon-Hoa G, Fontecave M. Flavin-Protein Complexes: Aromatic Stacking Assisted by a Hydrogen Bond. Biochemistry 2015; 54:4354-64. [PMID: 26120776 DOI: 10.1021/acs.biochem.5b00501] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Enzyme-catalyzed reactions often rely on a noncovalently bound cofactor whose reactivity is tuned by its immediate environment. Flavin cofactors, the most versatile catalyst encountered in biology, are often maintained within the protein throughout numbers of complex ionic and aromatic interactions. Here, we have investigated the role of π-π stacking and hydrogen bond interactions between a tyrosine and the isoalloxazine moiety of the flavin adenine dinucleotide (FAD) in an FAD-dependent RNA methyltransferase. Combining several static and time-resolved spectroscopies as well as biochemical approaches, we showed that aromatic stacking is assisted by a hydrogen bond between the phenol group and the amide of an adjacent active site loop. A mechanism of recognition and binding of the redox cofactor is proposed.
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Affiliation(s)
- Djemel Hamdane
- †Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège De France, France 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
| | - Charles Bou-Nader
- †Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège De France, France 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
| | - David Cornu
- ‡INSERM U779, 78 Rue du Général Leclerc, 94275 Le Kremlin-Bicêtre, France
| | - Gaston Hui-Bon-Hoa
- §Plateforme IMAGIF, Centre de Recherche de Gif, Centre National de la Recherche Scientifique, 1 avenue de le terrasse, 91191 Gif Sur Yvette, France
| | - Marc Fontecave
- †Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège De France, France 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
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Miletti T, Di Trani J, Jr Levros LC, Mittermaier A. Conformational plasticity surrounding the active site of NADH oxidase from Thermus thermophilus. Protein Sci 2015; 24:1114-28. [PMID: 25970557 PMCID: PMC4500311 DOI: 10.1002/pro.2693] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 04/26/2015] [Indexed: 11/08/2022]
Abstract
Biotechnological applications of enzymes can involve the use of these molecules under nonphysiological conditions. Thus, it is of interest to understand how environmental variables affect protein structure and dynamics and how this ultimately modulates enzyme function. NADH oxidase (NOX) from Thermus thermophilus exemplifies how enzyme activity can be tuned by reaction conditions, such as temperature, cofactor substitution, and the addition of cosolutes. This enzyme catalyzes the oxidation of reduced NAD(P)H to NAD(P)(+) with the concurrent reduction of O2 to H2O2, with relevance to biosensing applications. It is thermophilic, with an optimum temperature of approximately 65°C and sevenfold lower activity at 25°C. Moderate concentrations (≈1M) of urea and other chaotropes increase NOX activity by up to a factor of 2.5 at room temperature. Furthermore, it is a flavoprotein that accepts either FMN or the much larger FAD as cofactor. We have used nuclear magnetic resonance (NMR) titration and (15)N spin relaxation experiments together with isothermal titration calorimetry to study how NOX structure and dynamics are affected by changes in temperature, the addition of urea and the substitution of the FMN cofactor with FAD. The majority of signals from NOX are quite insensitive to changes in temperature, cosolute addition, and cofactor substitution. However, a small cluster of residues surrounding the active site shows significant changes. These residues are implicated in coupling changes in the solution conditions of the enzyme to changes in catalytic activity.
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Affiliation(s)
- Teresa Miletti
- Department of Chemistry, McGill UniversityMontreal, Quebec, H3A 0B8
| | - Justin Di Trani
- Department of Chemistry, McGill UniversityMontreal, Quebec, H3A 0B8
| | - Louis-Charles Jr Levros
- Laboratoire de biologie moléculaire, Département des Sciences Biologiques, Centre BioMed, Université du Québec à MontréalMontréal, Québec, H3C 3P8
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Li W, Wang J, Zhang J, Wang W. Molecular simulations of metal-coupled protein folding. Curr Opin Struct Biol 2015; 30:25-31. [DOI: 10.1016/j.sbi.2014.11.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 11/24/2014] [Accepted: 11/24/2014] [Indexed: 01/22/2023]
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