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Giraud A, Imbert L, Favier A, Henot F, Duffieux F, Samson C, Frances O, Crublet E, Boisbouvier J. Enabling site-specific NMR investigations of therapeutic Fab using a cell-free based isotopic labeling approach: application to anti-LAMP1 Fab. JOURNAL OF BIOMOLECULAR NMR 2024; 78:73-86. [PMID: 38546905 DOI: 10.1007/s10858-023-00433-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 12/22/2023] [Indexed: 06/15/2024]
Abstract
Monoclonal antibodies (mAbs) are biotherapeutics that have achieved outstanding success in treating many life-threatening and chronic diseases. The recognition of an antigen is mediated by the fragment antigen binding (Fab) regions composed by four different disulfide bridge-linked immunoglobulin domains. NMR is a powerful method to assess the integrity, the structure and interaction of Fabs, but site specific analysis has been so far hampered by the size of the Fabs and the lack of approaches to produce isotopically labeled samples. We proposed here an efficient in vitro method to produce [15N, 13C, 2H]-labeled Fabs enabling high resolution NMR investigations of these powerful therapeutics. As an open system, the cell-free expression mode enables fine-tuned control of the redox potential in presence of disulfide bond isomerase to enhance the formation of native disulfide bonds. Moreover, inhibition of transaminases in the S30 cell-free extract offers the opportunity to produce perdeuterated Fab samples directly in 1H2O medium, without the need for a time-consuming and inefficient refolding process. This specific protocol was applied to produce an optimally labeled sample of a therapeutic Fab, enabling the sequential assignment of 1HN, 15N, 13C', 13Cα, 13Cβ resonances of a full-length Fab. 90% of the backbone resonances of a Fab domain directed against the human LAMP1 glycoprotein were assigned successfully, opening new opportunities to study, at atomic resolution, Fabs' higher order structures, dynamics and interactions, using solution-state NMR.
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Affiliation(s)
- Arthur Giraud
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), 71, Avenue des Martyrs, 38044, Grenoble, France
- Sanofi Research & Development, 94403, Vitry-sur-Seine, France
- NMR-Bio, 5 place Robert Schuman, 38025, Grenoble, France
| | - Lionel Imbert
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), 71, Avenue des Martyrs, 38044, Grenoble, France
| | - Adrien Favier
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), 71, Avenue des Martyrs, 38044, Grenoble, France
| | - Faustine Henot
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), 71, Avenue des Martyrs, 38044, Grenoble, France
- Sanofi Research & Development, 94403, Vitry-sur-Seine, France
| | | | - Camille Samson
- Sanofi Research & Development, 94403, Vitry-sur-Seine, France
| | - Oriane Frances
- Sanofi Research & Development, 94403, Vitry-sur-Seine, France.
| | - Elodie Crublet
- NMR-Bio, 5 place Robert Schuman, 38025, Grenoble, France.
| | - Jérôme Boisbouvier
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), 71, Avenue des Martyrs, 38044, Grenoble, France.
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2
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Quaye JA, Wood KE, Snelgrove C, Ouedraogo D, Gadda G. An active site mutation induces oxygen reactivity in D-arginine dehydrogenase: A case of superoxide diverting protons. J Biol Chem 2024; 300:107381. [PMID: 38762175 PMCID: PMC11193025 DOI: 10.1016/j.jbc.2024.107381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/09/2024] [Accepted: 05/13/2024] [Indexed: 05/20/2024] Open
Abstract
Enzymes are potent catalysts that increase biochemical reaction rates by several orders of magnitude. Flavoproteins are a class of enzymes whose classification relies on their ability to react with molecular oxygen (O2) during catalysis using ionizable active site residues. Pseudomonas aeruginosa D-arginine dehydrogenase (PaDADH) is a flavoprotein that oxidizes D-arginine for P. aeruginosa survival and biofilm formation. The crystal structure of PaDADH reveals the interaction of the glutamate 246 (E246) side chain with the substrate and at least three other active site residues, establishing a hydrogen bond network in the active site. Additionally, E246 likely ionizes to facilitate substrate binding during PaDADH catalysis. This study aimed to investigate how replacing the E246 residue with leucine affects PaDADH catalysis and its ability to react with O2 using steady-state kinetics coupled with pH profile studies. The data reveal a gain of O2 reactivity in the E246L variant, resulting in a reduced flavin semiquinone species and superoxide (O2•-) during substrate oxidation. The O2•- reacts with active site protons, resulting in an observed nonstoichiometric slope of 1.5 in the enzyme's log (kcat/Km) pH profile with D-arginine. Adding superoxide dismutase results in an observed correction of the slope to 1.0. This study demonstrates how O2•- can alter the slopes of limbs in the pH profiles of flavin-dependent enzymes and serves as a model for correcting nonstoichiometric slopes in elucidating reaction mechanisms of flavoproteins.
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Affiliation(s)
- Joanna A Quaye
- Department of Chemistry, Georgia State University, Atlanta, Georgia, USA
| | - Kendall E Wood
- Biology Department, Morehouse College, Atlanta, Georgia, USA
| | - Claire Snelgrove
- The Gwinnett School of Mathematics, Science, and Technology, Lawrenceville, Georgia, USA
| | - Daniel Ouedraogo
- Department of Chemistry, Georgia State University, Atlanta, Georgia, USA
| | - Giovanni Gadda
- Department of Chemistry, Georgia State University, Atlanta, Georgia, USA; Department of Biology, Georgia State University, Atlanta, Georgia, USA; Department of the Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia, USA.
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3
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Méndez AAE, Argüello JM, Soncini FC, Checa SK. Scs system links copper and redox homeostasis in bacterial pathogens. J Biol Chem 2024; 300:105710. [PMID: 38309504 PMCID: PMC10907172 DOI: 10.1016/j.jbc.2024.105710] [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: 08/11/2023] [Revised: 01/09/2024] [Accepted: 01/16/2024] [Indexed: 02/05/2024] Open
Abstract
The bacterial envelope is an essential compartment involved in metabolism and metabolites transport, virulence, and stress defense. Its roles become more evident when homeostasis is challenged during host-pathogen interactions. In particular, the presence of free radical groups and excess copper in the periplasm causes noxious reactions, such as sulfhydryl group oxidation leading to enzymatic inactivation and protein denaturation. In response to this, canonical and accessory oxidoreductase systems are induced, performing quality control of thiol groups, and therefore contributing to restoring homeostasis and preserving survival under these conditions. Here, we examine recent advances in the characterization of the Dsb-like, Salmonella-specific Scs system. This system includes the ScsC/ScsB pair of Cu+-binding proteins with thiol-oxidoreductase activity, an alternative ScsB-partner, the membrane-linked ScsD, and a likely associated protein, ScsA, with a role in peroxide resistance. We discuss the acquisition of the scsABCD locus and its integration into a global regulatory pathway directing envelope response to Cu stress during the evolution of pathogens that also harbor the canonical Dsb systems. The evidence suggests that the canonical Dsb systems cannot satisfy the extra demands that the host-pathogen interface imposes to preserve functional thiol groups. This resulted in the acquisition of the Scs system by Salmonella. We propose that the ScsABCD complex evolved to connect Cu and redox stress responses in this pathogen as well as in other bacterial pathogens.
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Affiliation(s)
- Andrea A E Méndez
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Rosario, Argentina
| | - José M Argüello
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Fernando C Soncini
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Rosario, Argentina
| | - Susana K Checa
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Rosario, Argentina.
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4
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Palma A, Rettenbacher LA, Moilanen A, Saaranen M, Gasser B, Ruddock LW. Komagataella phaffii Erp41 is a protein disulfide isomerase with unprecedented disulfide bond catalyzing activity when coupled to glutathione. J Biol Chem 2024; 300:105746. [PMID: 38354787 PMCID: PMC10938136 DOI: 10.1016/j.jbc.2024.105746] [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: 01/02/2024] [Revised: 02/05/2024] [Accepted: 02/07/2024] [Indexed: 02/16/2024] Open
Abstract
In the methylotrophic yeast Komagataella phaffii, we identified an endoplasmic reticulum-resident protein disulfide isomerase (PDI) family member, Erp41, with a peculiar combination of active site motifs. Like fungal ERp38, it has two thioredoxin-like domains which contain active site motifs (a and a'), followed by an alpha-helical ERp29c C-terminal domain (c domain). However, while the a domain has a typical PDI-like active site motif (CGHC), the a' domain instead has CGYC, a glutaredoxin-like motif which confers to the protein an exceptional affinity for GSH/GSSG. This combination of active site motifs has so far been unreported in PDI-family members. Homology searches revealed ERp41 is present in the genome of some plants, fungal parasites, and a few nonconventional yeasts, among which are Komagataella spp. and Yarrowia lipolytica. These yeasts are both used for the production of secreted recombinant proteins. Here, we analyzed the activity of K. phaffii Erp41. We report that it is nonessential in K. phaffii, and that it can catalyze disulfide bond formation in partnership with the sulfhydryl oxidase Ero1 in vitro with higher turnover rates than the canonical PDI from K. phaffii, Pdi1, but slower activation times. We show how Erp41 has unusually fast glutathione-coupled oxidation activity and relate it to its unusual combination of active sites in its thioredoxin-like domains. We further describe how this determines its unusually efficient catalysis of dithiol oxidation in peptide and protein substrates.
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Affiliation(s)
- Arianna Palma
- Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria; Austrian Centre of Industrial Biotechnology, Vienna, Austria
| | - Lukas A Rettenbacher
- School of Biosciences, University of Kent, Canterbury, UK; Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Antti Moilanen
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Mirva Saaranen
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Brigitte Gasser
- Department of Biotechnology, Institute of Microbiology and Microbial Biotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria; Austrian Centre of Industrial Biotechnology, Vienna, Austria
| | - Lloyd W Ruddock
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.
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West JD. Experimental Approaches for Investigating Disulfide-Based Redox Relays in Cells. Chem Res Toxicol 2022; 35:1676-1689. [PMID: 35771680 DOI: 10.1021/acs.chemrestox.2c00123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Reversible oxidation of cysteine residues within proteins occurs naturally during normal cellular homeostasis and can increase during oxidative stress. Cysteine oxidation often leads to the formation of disulfide bonds, which can impact protein folding, stability, and function. Work in both prokaryotic and eukaryotic models over the past five decades has revealed several multiprotein systems that use thiol-dependent oxidoreductases to mediate disulfide bond reduction, formation, and/or rearrangement. Here, I provide an overview of how these systems operate to carry out disulfide exchange reactions in different cellular compartments, with a focus on their roles in maintaining redox homeostasis, transducing redox signals, and facilitating protein folding. Additionally, I review thiol-independent and thiol-dependent approaches for interrogating what proteins partner together in such disulfide-based redox relays. While the thiol-independent approaches rely either on predictive measures or standard procedures for monitoring protein-protein interactions, the thiol-dependent approaches include direct disulfide trapping methods as well as thiol-dependent chemical cross-linking. These strategies may prove useful in the systematic characterization of known and newly discovered disulfide relay mechanisms and redox switches involved in oxidant defense, protein folding, and cell signaling.
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Affiliation(s)
- James D West
- Biochemistry & Molecular Biology Program, Departments of Biology and Chemistry, The College of Wooster, Wooster, Ohio 44691, United States
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6
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Kleinberg A, Joseph R, Mao Y, Li N. Ultrasensitive disulfide scrambling analysis of mAbs by LC-MS with post-column reduction and glycine signal enhancement. Anal Biochem 2022; 653:114773. [PMID: 35688259 DOI: 10.1016/j.ab.2022.114773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 05/20/2022] [Accepted: 05/31/2022] [Indexed: 11/15/2022]
Abstract
Explicitly confirming the complete disulfide bond linkage pattern of a monoclonal antibody (mAb) presents a challenge in the biopharmaceutical industry. Although proper native disulfide connections are in high abundance for analytical purposes within a peptide mapping digest under non-reducing conditions, disulfide scrambling can also exist but be difficult to detect, let alone characterize, particularly at low levels. Here, we developed an ultrasensitive high-confidence method for identifying explicit disulfide connectivity in mAbs. By applying a post-column addition of tris (2-carboxyethyl)phosphine hydrochloride (TCEP) to the liquid chromatography (LC) eluent of a non-reduced mAb digest, partial reduction of disulfide peptides is achieved after the initial peptide separation, allowing both the parent disulfide and its reduced daughter peptides to co-elute for simultaneous mass spectrometry (MS) detection. Combining this concept with the recently discovered ability of glycine to enhance MS signal when added to the LC eluent, we demonstrate a method for detecting, characterizing and quantifying low-abundance disulfide scrambling in mAbs.
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Affiliation(s)
- Andrew Kleinberg
- Analytical Chemistry, Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY, 10591, United States
| | - Rachel Joseph
- Analytical Chemistry, Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY, 10591, United States
| | - Yuan Mao
- Analytical Chemistry, Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY, 10591, United States.
| | - Ning Li
- Analytical Chemistry, Regeneron Pharmaceuticals, Inc., 777 Old Saw Mill River Road, Tarrytown, NY, 10591, United States
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7
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Soon JW, Oohora K, Hayashi T. A disulphide bond-mediated hetero-dimer of a hemoprotein and a fluorescent protein exhibiting efficient energy transfer †. RSC Adv 2022; 12:28519-28524. [PMID: 36320522 PMCID: PMC9535469 DOI: 10.1039/d2ra05249k] [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: 08/21/2022] [Accepted: 09/22/2022] [Indexed: 11/07/2022] Open
Abstract
Artificial protein hetero-dimerization is one of the promising strategies to construct protein-based chemical tools. In this work, cytochrome b562, an electron transfer hemoprotein, and green fluorescent protein (GFP) mutants with cysteine residues added to their surfaces were conjugated via a pyridyl disulphide-based thiol–disulfide exchange reaction. The eight hetero-dimers, which have cysteine residues at different positions to form the disulphide bonds, were obtained and characterized by gel-electrophoresis, mass spectrometry and size exclusion chromatography. The fluorescence properties of the hetero-dimers were evaluated by fluorescence spectroscopy and fluorescence lifetime measurements. Efficient photoinduced energy transfer from the GFP chromophore to the heme cofactor was observed in each of the hetero-dimers. The energy transfer efficiency is strongly dependent on the cross-linking residues, reaching 96%. Furthermore, the estimated Förster distance and the structure-based maximum possible distances of the donor and acceptor suggest that one of the hetero-dimers has a rigid protein–protein structure with favourable properties for energy transfer. The disulphide bond-mediated protein hetero-dimerization is useful for screening functional protein systems towards further developments. Hetero-dimerization of a hemoprotein and green fluorescent protein via a thiol–disulphide exchange reaction is achieved. The heterodimer has suitable cross-linking points and displays efficient energy transfer.![]()
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Affiliation(s)
- Julian Wong Soon
- Department of Applied Chemistry, Graduate School of Engineering, Osaka UniversitySuita565-0871Japan
| | - Koji Oohora
- Department of Applied Chemistry, Graduate School of Engineering, Osaka UniversitySuita565-0871Japan
| | - Takashi Hayashi
- Department of Applied Chemistry, Graduate School of Engineering, Osaka UniversitySuita565-0871Japan
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8
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Sandberg MW, Bunkenborg J, Thyssen S, Villadsen M, Kofoed T. Characterization of a novel + 70 Da modification in rhGM-CSF expressed in E. coli using chemical assays in combination with mass spectrometry. Amino Acids 2021; 54:601-613. [PMID: 34453584 PMCID: PMC9117350 DOI: 10.1007/s00726-021-03004-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 05/11/2021] [Indexed: 10/26/2022]
Abstract
Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a cytokine and a white blood cell growth factor that has found usage as a therapeutic protein. During analysis of different fermentation batches of GM-CSF recombinantly expressed in E. coli, a covalent modification was identified on the protein by intact mass spectrometry. The modification gave a mass shift of + 70 Da and peptide mapping analysis demonstrated that it located to the protein N-terminus and lysine side chains. The chemical composition of C4H6O was found to be the best candidate by peptide fragmentation using tandem mass spectrometry. The modification likely contains a carbonyl group, since the mass of the modification increased by 2 Da by reduction with borane pyridine complex and it reacted with 2,4-dinitrophenylhydrazine. On the basis of chemical and tandem mass spectrometry fragmentation behavior, the modification could be attributed to crotonaldehyde, a reactive compound formed during lipid peroxidation. A low recorded oxygen pressure in the reactor during protein expression could be linked to the formation of this compound. This study shows the importance of maintaining full control over all reaction parameters during recombinant protein production.
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Li Y, Noro J, Martins M, Jing S, Silva C, Cavaco-Paulo A. Changing the shape of wool yarns via laccase-mediated grafting of tyrosine. J Biotechnol 2021; 339:73-80. [PMID: 34364924 DOI: 10.1016/j.jbiotec.2021.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 07/08/2021] [Accepted: 08/03/2021] [Indexed: 10/20/2022]
Abstract
The shape of wool yarns was changed by laccase-assisted grafting of tyrosine. Prior to tyrosine grafting a cysteine pre-treatment was optimized aiming to increase the amount of thiol reaction groups available. The best operational conditions for laccase-assisted tyrosine grafting were: i) pre-treatment with cysteine (2.2 mM) in a solution of 20 % ethanol, 15 % propylene glycol and 0.5 % benzyl alcohol, pH = 10, 40 °C; ii) tyrosine grafting with 3.0 mM tyrosine, 18 U/mL laccase, pH = 5, 40 °C. The shape modification was evaluated by number of curly twists determination on the grafted yarn samples. The thermal and mechanical properties of the grafted wool yarns was evaluated by TGA, DSC and breaking strength determination. The amount of free thiols and weight gain were assessed aiming to infer the role of the cysteine pre-treatment on the final tyrosine grafting and shape modification. The laccase-assisted grafting of tyrosine onto wool yarns have influenced the thermal and mechanical properties of the yarns however without compromising their structural integrity for the final application purposes. The developed methodology to impart new shape to wool yarns is presented herein as an environmentally friendly alternative to chemical methods. The new findings revealed great potentialities for application in similar fibers like hair.
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Affiliation(s)
- Yu Li
- Jiangsu Engineering Technology Research Centre of Functional Textiles, Jiangnan University, 214122, Wuxi, China; Key Laboratory of Eco-textiles, Jiangnan University, Ministry of Education, China; International Joint Research Laboratory for Textile and Fiber Bioprocesses, Jiangnan University, 214122, Wuxi, China
| | - Jennifer Noro
- Center of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Madalena Martins
- Center of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Su Jing
- Jiangsu Engineering Technology Research Centre of Functional Textiles, Jiangnan University, 214122, Wuxi, China; Key Laboratory of Eco-textiles, Jiangnan University, Ministry of Education, China; International Joint Research Laboratory for Textile and Fiber Bioprocesses, Jiangnan University, 214122, Wuxi, China
| | - Carla Silva
- Center of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
| | - Artur Cavaco-Paulo
- Jiangsu Engineering Technology Research Centre of Functional Textiles, Jiangnan University, 214122, Wuxi, China; Key Laboratory of Eco-textiles, Jiangnan University, Ministry of Education, China; International Joint Research Laboratory for Textile and Fiber Bioprocesses, Jiangnan University, 214122, Wuxi, China; Center of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
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10
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Wang YP, Wu EJ, Lurwanu Y, Ding JP, He DC, Waheed A, Nkurikiyimfura O, Liu ST, Li WY, Wang ZH, Yang L, Zhan J. Evidence for a synergistic effect of post-translational modifications and genomic composition of eEF-1α on the adaptation of Phytophthora infestans. Ecol Evol 2021; 11:5484-5496. [PMID: 34026022 PMCID: PMC8131795 DOI: 10.1002/ece3.7442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 02/19/2021] [Accepted: 02/21/2021] [Indexed: 12/18/2022] Open
Abstract
Genetic variation plays a fundamental role in pathogen's adaptation to environmental stresses. Pathogens with low genetic variation tend to survive and proliferate more poorly due to their lack of genotypic/phenotypic polymorphisms in responding to fluctuating environments. Evolutionary theory hypothesizes that the adaptive disadvantage of genes with low genomic variation can be compensated for structural diversity of proteins through post-translation modification (PTM) but this theory is rarely tested experimentally and its implication to sustainable disease management is hardly discussed. In this study, we analyzed nucleotide characteristics of eukaryotic translation elongation factor-1α (eEF-lα) gene from 165 Phytophthora infestans isolates and the physical and chemical properties of its derived proteins. We found a low sequence variation of eEF-lα protein, possibly attributable to purifying selection and a lack of intra-genic recombination rather than reduced mutation. In the only two isoforms detected by the study, the major one accounted for >95% of the pathogen collection and displayed a significantly higher fitness than the minor one. High lysine representation enhances the opportunity of the eEF-1α protein to be methylated and the absence of disulfide bonds is consistent with the structural prediction showing that many disordered regions are existed in the protein. Methylation, structural disordering, and possibly other PTMs ensure the ability of the protein to modify its functions during biological, cellular and biochemical processes, and compensate for its adaptive disadvantage caused by sequence conservation. Our results indicate that PTMs may function synergistically with nucleotide codes to regulate the adaptive landscape of eEF-1α, possibly as well as other housekeeping genes, in P. infestans. Compensatory evolution between pre- and post-translational phase in eEF-1α could enable pathogens quickly adapting to disease management strategies while efficiently maintaining critical roles of the protein playing in biological, cellular, and biochemical activities. Implications of these results to sustainable plant disease management are discussed.
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Affiliation(s)
- Yan-Ping Wang
- Key lab for Bio pesticide and Chemical Biology Ministry of Education Fujian Agriculture and Forestry University Fuzhou China
| | - E-Jiao Wu
- Key lab for Bio pesticide and Chemical Biology Ministry of Education Fujian Agriculture and Forestry University Fuzhou China
| | - Yahuza Lurwanu
- Key lab for Bio pesticide and Chemical Biology Ministry of Education Fujian Agriculture and Forestry University Fuzhou China
- Department of Crop Protection Bayero University Kano Kano Nigeria
| | - Ji-Peng Ding
- Key lab for Bio pesticide and Chemical Biology Ministry of Education Fujian Agriculture and Forestry University Fuzhou China
| | - Dun-Chun He
- School of Economics and Trade Fujian Jiangxia University Fuzhou China
| | - Abdul Waheed
- Key lab for Bio pesticide and Chemical Biology Ministry of Education Fujian Agriculture and Forestry University Fuzhou China
| | - Oswald Nkurikiyimfura
- Key lab for Bio pesticide and Chemical Biology Ministry of Education Fujian Agriculture and Forestry University Fuzhou China
| | - Shi-Ting Liu
- Key lab for Bio pesticide and Chemical Biology Ministry of Education Fujian Agriculture and Forestry University Fuzhou China
| | - Wen-Yang Li
- Key lab for Bio pesticide and Chemical Biology Ministry of Education Fujian Agriculture and Forestry University Fuzhou China
| | - Zong-Hua Wang
- Fujian University Key Laboratory for Plant-Microbe Interaction College of Life Sciences Fujian Agriculture and Forestry University Fuzhou China
- Institute of Oceanography Minjiang University Fuzhou China
| | - Lina Yang
- Key lab for Bio pesticide and Chemical Biology Ministry of Education Fujian Agriculture and Forestry University Fuzhou China
- Institute of Oceanography Minjiang University Fuzhou China
| | - Jiasui Zhan
- Department of Forest Mycology and Plant Pathology Swedish University of Agricultural Sciences Uppsala Sweden
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11
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Zhang B, Zhao H, Wu X, Zhang LQ. The Oxidoreductase DsbA1 negatively influences 2,4-diacetylphloroglucinol biosynthesis by interfering the function of Gcd in Pseudomonas fluorescens 2P24. BMC Microbiol 2020; 20:39. [PMID: 32093646 PMCID: PMC7041245 DOI: 10.1186/s12866-020-1714-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 01/27/2020] [Indexed: 02/03/2023] Open
Abstract
Background The polyketide antibiotic 2,4-diacetylphloroglucinol (2,4-DAPG), produced by Pseudomonas fluorescens 2P24, is positively regulated by the GacS-GacA two-component system. Results Here we reported on the characterization of DsbA1 (disulfide oxidoreductase) as novel regulator of biocontrol activity in P. fluorescens. Our data showed that mutation of dsbA1 caused the accumulation of 2,4-DAPG in a GacA-independent manner. Further analysis indicated that DsbA1 interacts with membrane-bound glucose dehydrogenase Gcd, which positively regulates the production of 2,4-DAPG. Mutation of cysteine (C)-235, C275, and C578 of Gcd, significantly reduced the interaction with DsbA1, enhanced the activity of Gcd and increased 2,4-DAPG production. Conclusions Our results suggest that DsbA1 regulates the 2,4-DAPG concentration via fine-tuning the function of Gcd in P. fluorescens 2P24.
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Affiliation(s)
- Bo Zhang
- College of Agriculture, Guangxi University, Nanning, 530004, China
| | - Hui Zhao
- College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Xiaogang Wu
- College of Agriculture, Guangxi University, Nanning, 530004, China.
| | - Li-Qun Zhang
- College of Plant Protection, China Agricultural University, Beijing, 100193, China.
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12
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Siddiquee R, Choi SSC, Lam SS, Wang P, Qi R, Otting G, Sunde M, Kwan AHY. Cell-free expression of natively folded hydrophobins. Protein Expr Purif 2020; 170:105591. [PMID: 32032769 DOI: 10.1016/j.pep.2020.105591] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 01/28/2020] [Accepted: 01/30/2020] [Indexed: 01/07/2023]
Abstract
Hydrophobins are a family of cysteine-rich proteins unique to filamentous fungi. The proteins are produced in a soluble form but self-assemble into organised amphipathic layers at hydrophilic:hydrophobic interfaces. These layers contribute to transitions between wet and dry environments, spore dispersal and attachment to surfaces for growth and infection. Hydrophobins are characterised by four disulphide bonds that are critical to their structure and function. Thus, obtaining correctly folded, soluble and functional hydrophobins directly from bacterial recombinant expression is challenging and in most cases, initial denaturation from inclusion bodies followed by oxidative refolding are required to obtain folded proteins. Here, we report the use of cell-free expression with E. coli cell lysate to directly obtain natively folded hydrophobins. All six of the hydrophobins tested could be expressed after optimisation of redox conditions. For some hydrophobins, the inclusion of the disulfide isomerase DsbC further enhanced expression levels. We are able to achieve a yield of up to 1 mg of natively folded hydrophobin per mL of reaction. This has allowed the confirmation of the correct folding of hydrophobins with the use of 15N-cysteine and 15N-1H nuclear magnetic resonance experiments within 24 h of starting from plasmid stocks.
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Affiliation(s)
- Rezwan Siddiquee
- The University of Sydney, School of Life and Environmental Sciences and SydneyNano, Australia
| | - Samuel Sung-Chan Choi
- The University of Sydney, School of Life and Environmental Sciences and SydneyNano, Australia
| | - Shirley Siuley Lam
- The University of Sydney, School of Life and Environmental Sciences and SydneyNano, Australia
| | - Patrick Wang
- The University of Sydney, School of Life and Environmental Sciences and SydneyNano, Australia
| | - Ruhu Qi
- Australian National University, Research School of Chemistry, Australia
| | - Gottfried Otting
- Australian National University, Research School of Chemistry, Australia
| | - Margaret Sunde
- The University of Sydney, School of Medical Sciences and SydneyNano, Australia
| | - Ann Hau-Yu Kwan
- The University of Sydney, School of Life and Environmental Sciences and SydneyNano, Australia.
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13
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Horváth D, Taricska N, Keszei E, Stráner P, Farkas V, Tóth GK, Perczel A. Compactness of Protein Folds Alters Disulfide-Bond Reducibility by Three Orders of Magnitude: A Comprehensive Kinetic Case Study on the Reduction of Differently Sized Tryptophan Cage Model Proteins. Chembiochem 2019; 21:681-695. [PMID: 31475422 PMCID: PMC7079008 DOI: 10.1002/cbic.201900470] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Indexed: 12/12/2022]
Abstract
A new approach to monitor disulfide-bond reduction in the vicinity of aromatic cluster(s) has been derived by using the near-UV range (λ=266-293 nm) of electronic circular dichroism (ECD) spectra. By combining the results from NMR and ECD spectroscopy, the 3D fold characteristics and associated reduction rate constants (k) of E19_SS, which is a highly thermostable, disulfide-bond reinforced 39-amino acid long exenatide mimetic, and its N-terminally truncated derivatives have been determined under different experimental conditions. Single disulfide bond reduction of the E19_SS model (with an 18-fold excess of tris(2-carboxyethyl)phosphine, pH 7, 37 °C) takes hours, which is 20-30 times longer than that expected, and thus, would not reach completion by applying commonly used reduction protocols. It is found that structural, steric, and electrostatic factors influence the reduction rate, resulting in orders of magnitude differences in reduction half-lives (900>t1/2 >1 min) even for structurally similar, well-folded derivatives of a small model protein.
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Affiliation(s)
- Dániel Horváth
- Laboratory of Structural Chemistry and Biology and, MTA-ELTE Protein Modeling Research Group at the Institute of Chemistry, Eötvös Loránd University, 112, P. O. Box 32, 1518, Budapest, Hungary
| | - Nóra Taricska
- Laboratory of Structural Chemistry and Biology and, MTA-ELTE Protein Modeling Research Group at the Institute of Chemistry, Eötvös Loránd University, 112, P. O. Box 32, 1518, Budapest, Hungary
| | - Ernő Keszei
- Chemical Kinetics Laboratory, Institute of Chemistry, Eötvös Loránd University, 112, P. O. Box 32, 1518, Budapest, Hungary
| | - Pál Stráner
- Laboratory of Structural Chemistry and Biology and, MTA-ELTE Protein Modeling Research Group at the Institute of Chemistry, Eötvös Loránd University, 112, P. O. Box 32, 1518, Budapest, Hungary
| | - Viktor Farkas
- Laboratory of Structural Chemistry and Biology and, MTA-ELTE Protein Modeling Research Group at the Institute of Chemistry, Eötvös Loránd University, 112, P. O. Box 32, 1518, Budapest, Hungary
| | - Gábor K Tóth
- Department of Medical Chemistry, Faculty of General Medicine, University of Szeged, Szeged Dóm tér 8, H-6720, Szeged, Hungary
| | - András Perczel
- Laboratory of Structural Chemistry and Biology and, MTA-ELTE Protein Modeling Research Group at the Institute of Chemistry, Eötvös Loránd University, 112, P. O. Box 32, 1518, Budapest, Hungary
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14
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Abstract
The formation of disulfide bonds is critical to the folding of many extracytoplasmic proteins in all domains of life. With the discovery in the early 1990s that disulfide bond formation is catalyzed by enzymes, the field of oxidative folding of proteins was born. Escherichia coli played a central role as a model organism for the elucidation of the disulfide bond-forming machinery. Since then, many of the enzymatic players and their mechanisms of forming, breaking, and shuffling disulfide bonds have become understood in greater detail. This article summarizes the discoveries of the past 3 decades, focusing on disulfide bond formation in the periplasm of the model prokaryotic host E. coli.
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15
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Exploring Castellaniella defragrans Linalool (De)hydratase-Isomerase for Enzymatic Hydration of Alkenes. Molecules 2019; 24:molecules24112092. [PMID: 31159367 PMCID: PMC6600392 DOI: 10.3390/molecules24112092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 05/30/2019] [Accepted: 05/31/2019] [Indexed: 01/08/2023] Open
Abstract
Acyclic monoterpenes constitute a large and highly abundant class of secondary plant metabolites and are, therefore, attractive low-cost raw materials for the chemical industry. To date, numerous biocatalysts for their transformation are known, giving access to highly sought-after monoterpenoids. In view of the high selectivity associated with many of these reactions, the demand for enzymes generating commercially important target molecules is unabated. Here, linalool (de)hydratase-isomerase (Ldi, EC 4.2.1.127) from Castellaniella defragrans was examined for the regio- and stereoselective hydration of the acyclic monoterpene β-myrcene to (S)-(+)-linalool. Expression of the native enzyme in Escherichia coli allowed for identification of bottlenecks limiting enzyme activity, which were investigated by mutating selected residues implied in enzyme assembly and function. Combining these analyses with the recently published 3D structures of Ldi highlighted the precisely coordinated reduction-oxidation state of two cysteine pairs in correct oligomeric assembly and the catalytic mechanism, respectively. Subcellular targeting studies upon fusion of Ldi to different signal sequences revealed the significance of periplasmic localization of the mature enzyme in the heterologous expression host. This study provides biochemical and mechanistic insight into the hydration of β-myrcene, a nonfunctionalized terpene, and emphasizes its potential for access to scarcely available but commercially interesting tertiary alcohols.
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Ruano-Gallego D, Fraile S, Gutierrez C, Fernández LÁ. Screening and purification of nanobodies from E. coli culture supernatants using the hemolysin secretion system. Microb Cell Fact 2019; 18:47. [PMID: 30857538 PMCID: PMC6410518 DOI: 10.1186/s12934-019-1094-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 02/25/2019] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND The hemolysin (Hly) secretion system of E. coli allows the one-step translocation of hemolysin A (HlyA) from the bacterial cytoplasm to the extracellular medium, without a periplasmic intermediate. In this work, we investigate whether the Hly secretion system of E. coli is competent to secrete a repertoire of functional single-domain VHH antibodies (nanobodies, Nbs), facilitating direct screening of VHH libraries and the purification of selected Nb from the extracellular medium. RESULTS We employed a phagemid library of VHHs obtained by immunization of a dromedary with three protein antigens from enterohemorrhagic E. coli (EHEC), namely, the extracellular secreted protein A (EspA), the extracellular C-terminal region of Intimin (Int280), and the translocated intimin receptor middle domain (TirM). VHH clones binding each antigen were enriched and amplified by biopanning, and subsequently fused to the C-terminal secretion signal of HlyA to be expressed and secreted in a E. coli strain carrying the Hly export machinery (HlyB, HlyD and TolC). Individual E. coli clones were grown and induced in 96-well microtiter plates, and the supernatants of the producing cultures directly used in ELISA for detection of Nbs binding EspA, Int280 and TirM. A set of Nb sequences specifically binding each of these antigens were identified, indicating that the Hly system is able to secrete a diversity of functional Nbs. We performed thiol alkylation assays demonstrating that Nbs are correctly oxidized upon secretion, forming disulphide bonds between cysteine pairs despite the absence of a periplasmic intermediate. In addition, we show that the secreted Nb-HlyA fusions can be directly purified from the supernatant of E. coli cultures, avoiding cell lysis and in a single affinity chromatography step. CONCLUSIONS Our data demonstrate the Hly secretion system of E. coli can be used as an expression platform for screening and purification of Nb binders from VHH repertories.
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Affiliation(s)
- David Ruano-Gallego
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Campus UAM-Cantoblanco, 28049 Madrid, Spain
| | - Sofía Fraile
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Campus UAM-Cantoblanco, 28049 Madrid, Spain
| | - Carlos Gutierrez
- Research Institute of Biomedical and Health Sciences, Veterinary Faculty, Universidad de Las Palmas de Gran Canaria (UPGC), 35413 Arucas, Las Palmas, Canary Islands Spain
| | - Luis Ángel Fernández
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Campus UAM-Cantoblanco, 28049 Madrid, Spain
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Chiu J, Hogg PJ. Allosteric disulfides: Sophisticated molecular structures enabling flexible protein regulation. J Biol Chem 2019; 294:2949-2960. [PMID: 30635401 DOI: 10.1074/jbc.rev118.005604] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Protein disulfide bonds link pairs of cysteine residues in polypeptide chains. Many of these bonds serve a purely structural or energetic role, but a growing subset of cleavable disulfide bonds has been shown to control the function of the mature protein in which they reside. These allosteric disulfides and the factors that cleave these bonds are being identified across biological systems and life forms and have been shown to control hemostasis, the immune response, and viral infection in mammals. The discovery of these functional disulfides and a rationale for their facile nature has been aided by the emergence of a conformational signature for allosteric bonds. This post-translational modification mostly occurs extracellularly, making these chemical events prime drug targets. Indeed, a membrane-impermeable inhibitor of one of the cleaving factors is currently being trialed as an antithrombotic agent in cancer patients. Allosteric disulfides are firmly established as a sophisticated means by which a protein's shape and function can be altered; however, the full scope of this biological regulation will not be realized without new tools and techniques to study this regulation and innovative ways of targeting it.
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Affiliation(s)
- Joyce Chiu
- From the Centenary Institute, National Health and Medical Research Council Clinical Trials Centre, Sydney Medical School, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - Philip J Hogg
- From the Centenary Institute, National Health and Medical Research Council Clinical Trials Centre, Sydney Medical School, University of Sydney, Camperdown, New South Wales 2006, Australia
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18
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Du P, Liu W, Cao H, Zhao H, Huang CH. Oxidation of amino acids by peracetic acid: Reaction kinetics, pathways and theoretical calculations. WATER RESEARCH X 2018; 1:100002. [PMID: 31367703 PMCID: PMC6646862 DOI: 10.1016/j.wroa.2018.09.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 09/14/2018] [Accepted: 09/15/2018] [Indexed: 05/28/2023]
Abstract
Peracetic acid (PAA) is a sanitizer with increasing use in food, medical and water treatment industries. Amino acids are important components in targeted foods for PAA treatment and ubiquitous in natural waterbodies and wastewater effluents as the primary form of dissolved organic nitrogen. To better understand the possible reactions, this work investigated the reaction kinetics and transformation pathways of selected amino acids towards PAA. Experimental results demonstrated that most amino acids showed sluggish reactivity to PAA except cysteine (CYS), methionine (MET), and histidine (HIS). CYS showed the highest reactivity with a very rapid reaction rate. Reactions of MET and HIS with PAA followed second-order kinetics with rate constants of 4.6 ± 0.2, and 1.8 ± 0.1 M-1⋅s-1 at pH 7, respectively. The reactions were faster at pH 5 and 7 than at pH 9 due to PAA speciation. Low concentrations of H2O2 coexistent with PAA contributed little to the oxidation of amino acids. The primary oxidation products of amino acids with PAA were [O] addition compounds on the reactive sites at thiol, thioether and imidazole groups. Theoretical calculations were applied to predict the reactivity and regioselectivity of PAA electrophilic attacks on amino acids and improved mechanistic understanding. As an oxidative disinfectant, the reaction of PAA with organics to form byproducts is inevitable; however, this study shows that PAA exhibits lower and more selective reactivity towards biomolecules such as amino acids than other common disinfectants, causing less concern of toxic disinfection byproducts. This attribute may allow greater stability and more targeted actions of PAA in various applications.
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Affiliation(s)
- Penghui Du
- Beijing Engineering Research Center of Process Pollution Control, Division of Environment Technology and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wen Liu
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Science and Engineering, Peking University, Beijing 100871, China
| | - Hongbin Cao
- Beijing Engineering Research Center of Process Pollution Control, Division of Environment Technology and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - He Zhao
- Beijing Engineering Research Center of Process Pollution Control, Division of Environment Technology and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Ching-Hua Huang
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States
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19
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Khoshtinat Nikkhoi S, Rahbarizadeh F, Ahmadvand D, Moghimi SM. Multivalent targeting and killing of HER2 overexpressing breast carcinoma cells with methotrexate-encapsulated tetra-specific non-overlapping variable domain heavy chain anti-HER2 antibody-PEG-liposomes: In vitro proof-of-concept. Eur J Pharm Sci 2018; 122:42-50. [DOI: 10.1016/j.ejps.2018.06.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 06/09/2018] [Accepted: 06/18/2018] [Indexed: 12/17/2022]
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20
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Large-Scale Generation of Recombinant Granulin Peptides in E. coli. Methods Mol Biol 2018; 1806:51-64. [PMID: 29956268 DOI: 10.1007/978-1-4939-8559-3_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Generating milligram quantities of correctly folded granulin molecules with properly formed disulfide bonds and biologically relevant activities may represent a considerable challenge. Here I describe a protocol for obtaining well-folded human granulins A, C, and F by expressing them as thioredoxin fusion proteins in Origami (DE3) Escherichia coli cells promoting disulfide bond formation in the cytoplasm environment. The thioredoxin tag is removed by proteolytic cleavage with enterokinase and granulins which are purified by reversed-phase HPLC. Well-folded disulfide species display lower retention time than misfolded species and therefore can be readily purified.
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21
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Barage SH, Deobagkar DD, Baladhye VB. Characterization of structural and functional role of selenocysteine in selenoprotein H and its impact on DNA binding. Amino Acids 2018; 50:593-607. [DOI: 10.1007/s00726-018-2543-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 02/15/2018] [Indexed: 12/13/2022]
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22
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Phosphatidylserine-Induced Conformational Modulation of Immune Cell Exhaustion-Associated Receptor TIM3. Sci Rep 2017; 7:13579. [PMID: 29051586 PMCID: PMC5648779 DOI: 10.1038/s41598-017-14064-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 10/05/2017] [Indexed: 01/25/2023] Open
Abstract
In the face of chronic cancers and protracted viral infections, human immune cells are known to adopt an exhausted state in which their effector functions are lost. In recent years, a number of inhibitory receptors have been connected to the immune cell exhaustion phenotype; furthermore, ligands capable of activating these receptors have been discovered. The molecular mechanisms by which these ligands affect the exhausted states of immune cells, however, are largely unknown. Here, we present the results of molecular dynamics simulations of one potential exhaustion-associated system: the complex of human inhibitory receptor TIM3 (hTIM3) and its ligand phosphatidylserine (PSF). We find that PSF fundamentally alters the electrostatic environment within hTIM3's Ca2+ binding site, facilitating the formation of a salt bridge and freeing a tyrosine-containing strand. This liberated tyrosine then collapses into a nearby hydrophobic pocket, anchoring a modified conformational ensemble typified by a β-strand rearrangement. The "electrostatic switching/hydrophobic anchoring" mechanism of conformational modulation reported here suggests a new type of process by which TIM3 activation might be achieved. This work also highlights strategies by which PSF-mediated conformational change could be controlled, either through administration of small molecules, execution of mutations, or modification of receptor phosphorylation states.
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23
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Park H, Kim YT, Choi C, Kim S. Tripodal Lipoprotein Variants with C-Terminal Hydrophobic Residues Allosterically Modulate Activity of the DegP Protease. J Mol Biol 2017; 429:3090-3101. [PMID: 28923470 DOI: 10.1016/j.jmb.2017.09.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 08/17/2017] [Accepted: 09/11/2017] [Indexed: 01/10/2023]
Abstract
DegP, a member of the highly conserved HtrA family of proteases, performs a regulated proteolysis of toxic misfolded proteins in the periplasm of Gram-negative bacteria. The allosteric switch between inactive and active conformations is a central mechanism to carefully control proteolytic activity of DegP and to maintain the optimal cellular fitness, but few other molecules than substrates are known to allosterically control DegP activity. Here, we demonstrate that a mutant variant of an outer-membrane lipoprotein, Lpp+Leu, can function as a novel allosteric effector that changes the dynamic range of DegP activity. The three leucines at the C-termini of trimeric Lpp+Leu are central components for activity modulation. Selection experiments with Lpp variant libraries show that Lpp variants with diverse sequences at or near C-termini, in particular those with hydrophobic residues at C-termini, function similarly to Lpp+Leu. Interestingly, Lpp variants carrying different residues at C-terminal, penultimate, or antepenultimate positions display dramatically different patterns of activation and inhibition effects, suggesting that their interactions with DegP differentially stabilize distinct inactive or active conformations. We propose that the tripodal structure with three hydrophobic ends that mimics Lpp+Leu is a novel platform for allosteric effectors, which may be useful in developing new antibiotics against DegP or homologous HtrA proteases.
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Affiliation(s)
- Hyojin Park
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Yurie T Kim
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Chulwon Choi
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Seokhee Kim
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea.
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24
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Ren GX, Guo XP, Sun YC. HmsC Controls Yersinia pestis Biofilm Formation in Response to Redox Environment. Front Cell Infect Microbiol 2017; 7:355. [PMID: 28848715 PMCID: PMC5550408 DOI: 10.3389/fcimb.2017.00355] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Accepted: 07/25/2017] [Indexed: 11/25/2022] Open
Abstract
Yersinia pestis biofilm formation, controlled by intracellular levels of the second messenger molecule cyclic diguanylate (c-di-GMP), is important for blockage-dependent plague transmission from fleas to mammals. HmsCDE is a tripartite signaling system that modulates intracellular c-di-GMP levels to regulate biofilm formation in Y. pestis. Previously, we found that Y. pestis biofilm formation is stimulated in reducing environments in an hmsCDE-dependent manner. However, the mechanism by which HmsCDE senses the redox state remains elusive. Using a dsbA mutant and the addition of Cu2+ to simulate reducing and oxidizing periplasmic environments, we found that HmsC protein levels are decreased and the HmsC-HmsD protein-protein interaction is weakened in a reducing environment. In addition, we revealed that intraprotein disulphide bonds are critical for HmsC since breakage lowers protein stability and diminishes the interaction with HmsD. Our results suggest that HmsC might play a major role in sensing the environmental changes.
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Affiliation(s)
- Gai-Xian Ren
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing, China
| | - Xiao-Peng Guo
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing, China
| | - Yi-Cheng Sun
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing, China
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25
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Abstract
Biofilms are communities of microbial cells that are encapsulated within a self-produced polymeric matrix. The matrix is critical to the success of biofilms in diverse habitats; however, many details of the composition, structure, and function remain enigmatic. Biofilms formed by the Gram-positive bacterium Bacillus subtilis depend on the production of the secreted film-forming protein BslA. Here, we show that a gradient of electron acceptor availability through the depth of the biofilm gives rise to two distinct functional roles for BslA and that these roles can be genetically separated through targeted amino acid substitutions. We establish that monomeric BslA is necessary and sufficient to give rise to complex biofilm architecture, whereas dimerization of BslA is required to render the community hydrophobic. Dimerization of BslA, mediated by disulfide bond formation, depends on two conserved cysteine residues located in the C-terminal region. Our findings demonstrate that bacteria have evolved multiple uses for limited elements in the matrix, allowing for alternative responses in a complex, changing environment.
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26
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Lim JK, Jung HC, Kang SG, Lee HS. Redox regulation of SurR by protein disulfide oxidoreductase in Thermococcus onnurineus NA1. Extremophiles 2017; 21:491-498. [PMID: 28251348 DOI: 10.1007/s00792-017-0919-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 02/13/2017] [Indexed: 01/22/2023]
Abstract
Protein disulfide oxidoreductases are redox enzymes that catalyze thiol-disulfide exchange reactions. These enzymes include thioredoxins, glutaredoxins, protein disulfide isomerases, disulfide bond formation A (DsbA) proteins, and Pyrococcus furiosus protein disulfide oxidoreductase (PfPDO) homologues. In the genome of a hyperthermophilic archaeon, Thermococcus onnurineus NA1, the genes encoding one PfPDO homologue (TON_0319, Pdo) and three more thioredoxin- or glutaredoxin-like proteins (TON_0470, TON_0472, TON_0834) were identified. All except TON_0470 were recombinantly expressed and purified. Three purified proteins were reduced by a thioredoxin reductase (TrxR), indicating that each protein can form redox complex with TrxR. SurR, a transcription factor involved in the sulfur response, was tested for a protein target of a TrxR-redoxin system and only Pdo was identified to be capable of catalyzing the reduction of SurR. Electromobility shift assay demonstrated that SurR reduced by the TrxR-Pdo system could bind to the DNA probe with the SurR-binding motif, GTTttgAAC. In this study, we present the TrxR-Pdo couple as a redox-regulator for SurR in T. onnurineus NA1.
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Affiliation(s)
- Jae Kyu Lim
- Marine Biotechnology Research Division, Korea Institute of Ocean Science and Technology, Ansan, 15627, Republic of Korea.,Department of Marine Biotechnology, Korea University of Science and Technology, Daejeon, 34113, Republic of Korea
| | - Hae-Chang Jung
- Marine Biotechnology Research Division, Korea Institute of Ocean Science and Technology, Ansan, 15627, Republic of Korea.,Department of Marine Biotechnology, Korea University of Science and Technology, Daejeon, 34113, Republic of Korea
| | - Sung Gyun Kang
- Marine Biotechnology Research Division, Korea Institute of Ocean Science and Technology, Ansan, 15627, Republic of Korea. .,Department of Marine Biotechnology, Korea University of Science and Technology, Daejeon, 34113, Republic of Korea.
| | - Hyun Sook Lee
- Marine Biotechnology Research Division, Korea Institute of Ocean Science and Technology, Ansan, 15627, Republic of Korea. .,Department of Marine Biotechnology, Korea University of Science and Technology, Daejeon, 34113, Republic of Korea.
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27
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Yuen CYL, Shek R, Kang BH, Matsumoto K, Cho EJ, Christopher DA. Arabidopsis protein disulfide isomerase-8 is a type I endoplasmic reticulum transmembrane protein with thiol-disulfide oxidase activity. BMC PLANT BIOLOGY 2016; 16:181. [PMID: 27549196 PMCID: PMC4994283 DOI: 10.1186/s12870-016-0869-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 08/08/2016] [Indexed: 05/26/2023]
Abstract
BACKGROUND In eukaryotes, classical protein disulfide isomerases (PDIs) facilitate the oxidative folding of nascent secretory proteins in the endoplasmic reticulum by catalyzing the formation, breakage, and rearrangement of disulfide bonds. Terrestrial plants encode six structurally distinct subfamilies of PDIs. The novel PDI-B subfamily is unique to terrestrial plants, and in Arabidopsis is represented by a single member, PDI8. Unlike classical PDIs, which lack transmembrane domains (TMDs), PDI8 is unique in that it has a C-terminal TMD and a single N-terminal thioredoxin domain (instead of two). No PDI8 isoforms have been experimentally characterized to date. Here we describe the characterization of the membrane orientation, expression, sub-cellular localization, and biochemical function of this novel member of the PDI family. RESULTS Histochemical staining of plants harboring a PDI8 promoter:β-glucuronidase (GUS) fusion revealed that the PDI8 promoter is highly active in young, expanding leaves, the guard cells of cotyledons, and in the vasculature of several organs, including roots, leaves, cotyledons, and flowers. Immunoelectron microscopy studies using a PDI8-specific antibody on root and shoot apical cells revealed that PDI8 localizes to the endoplasmic reticulum (ER). Transient expression of two PDI8 fusions to green fluorescent protein (spGFP-PDI8 and PDI8-GFP-KKED) in leaf mesophyll protoplasts also resulted in labeling of the ER. Protease-protection immunoblot analysis indicated that PDI8 is a type I membrane protein, with its catalytic domain facing the ER lumen. The lumenal portion of PDI8 was able to functionally complement the loss of the prokaryotic protein foldase, disulfide oxidase (DsbA), as demonstrated by the reconstitution of periplasmic alkaline phosphatase in Escherichia coli. CONCLUSION The results indicate that PDI8 is a type I transmembrane protein with its catalytic domain facing the lumen of the ER and functions in the oxidation of cysteines to produce disulfide bonds. It likely plays a role in folding newly-synthesized secretory proteins as they translocate across the ER membrane into the lumen. These foundational results open the door to identifying the substrates of PDI8 to enable a more thorough understanding of its function in plants.
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Affiliation(s)
- Christen Y. L. Yuen
- Department of Molecular Biosciences and Bioengineering, University of Hawaii, 1955 East-West Rd., Ag. Science Rm 218, Honolulu, HI 96822 USA
| | - Roger Shek
- Department of Molecular Biosciences and Bioengineering, University of Hawaii, 1955 East-West Rd., Ag. Science Rm 218, Honolulu, HI 96822 USA
| | - Byung-Ho Kang
- The Chinese University of Hong Kong, School of Life Sciences, Shatin, Hong Kong, SAR China
| | - Kristie Matsumoto
- Department of Molecular Biosciences and Bioengineering, University of Hawaii, 1955 East-West Rd., Ag. Science Rm 218, Honolulu, HI 96822 USA
| | - Eun Ju Cho
- Department of Molecular Biosciences and Bioengineering, University of Hawaii, 1955 East-West Rd., Ag. Science Rm 218, Honolulu, HI 96822 USA
| | - David A. Christopher
- Department of Molecular Biosciences and Bioengineering, University of Hawaii, 1955 East-West Rd., Ag. Science Rm 218, Honolulu, HI 96822 USA
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28
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Rollauer SE, Sooreshjani MA, Noinaj N, Buchanan SK. Outer membrane protein biogenesis in Gram-negative bacteria. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2015.0023. [PMID: 26370935 DOI: 10.1098/rstb.2015.0023] [Citation(s) in RCA: 158] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Gram-negative bacteria contain a double membrane which serves for both protection and for providing nutrients for viability. The outermost of these membranes is called the outer membrane (OM), and it contains a host of fully integrated membrane proteins which serve essential functions for the cell, including nutrient uptake, cell adhesion, cell signalling and waste export. For pathogenic strains, many of these outer membrane proteins (OMPs) also serve as virulence factors for nutrient scavenging and evasion of host defence mechanisms. OMPs are unique membrane proteins in that they have a β-barrel fold and can range in size from 8 to 26 strands, yet can still serve many different functions for the cell. Despite their essential roles in cell survival and virulence, the exact mechanism for the biogenesis of these OMPs into the OM has remained largely unknown. However, the past decade has witnessed significant progress towards unravelling the pathways and mechanisms necessary for moulding a nascent polypeptide into a functional OMP within the OM. Here, we will review some of these recent discoveries that have advanced our understanding of the biogenesis of OMPs in Gram-negative bacteria, starting with synthesis in the cytoplasm to folding and insertion into the OM.
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Affiliation(s)
- Sarah E Rollauer
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Moloud A Sooreshjani
- Markey Center for Structural Biology, Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Nicholas Noinaj
- Markey Center for Structural Biology, Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Susan K Buchanan
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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29
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Yang L, Lu Y, Soto RJ, Shah A, Ahonen MJR, Schoenfisch MH. S-Nitrosothiol-modified hyperbranched polyesters. Polym Chem 2016. [DOI: 10.1039/c6py01516f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
S-Nitrosothiol-modified hyperbranched polyesters as a novel biodegradable nitric oxide-releasing scaffold.
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Affiliation(s)
- Lei Yang
- Department of Chemistry
- University of North Carolina – Chapel Hill
- Chapel Hill
- USA
| | - Yuan Lu
- Department of Chemistry
- University of North Carolina – Chapel Hill
- Chapel Hill
- USA
| | - Robert J. Soto
- Department of Chemistry
- University of North Carolina – Chapel Hill
- Chapel Hill
- USA
| | - Anand Shah
- Department of Chemistry
- University of North Carolina – Chapel Hill
- Chapel Hill
- USA
| | | | - Mark H. Schoenfisch
- Department of Chemistry
- University of North Carolina – Chapel Hill
- Chapel Hill
- USA
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30
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Co-expression of disulfide oxidoreductases DsbA/DsbC markedly enhanced soluble and functional expression of reteplase in Escherichia coli. J Biotechnol 2015; 192 Pt A:197-203. [PMID: 25449110 DOI: 10.1016/j.jbiotec.2014.10.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Revised: 10/18/2014] [Accepted: 10/21/2014] [Indexed: 11/24/2022]
Abstract
Reteplase is the third generation of thrombolytic medicine and has many advantages over commercial t-PA. However, over-expressing recombinant reteplase in E. coli always accumulates as inclusion bodies due to nine pairs of disulfide bonds formation that is the main obstacle for correct folding. In this paper, in order to enhance soluble expression of recombinant reteplase in E. coli, DsbA/DsbC foldases were used to introduce disulfide bonds into the reduced polypeptide chain and catalyze their isomerization to the native disulfide linkage during the folding process. Firstly multiple E. coli protein expression systems, i.e. DsbA, DsbC and DsbA/DsbC co-expression were constructed. Subsequently, IPTG and l-arabinose were added to induce expression of foldases and reteplase accordingly, and experimental parameters such as culture temperature and inducer concentration were optimized. As a result, the co-expression system markedly enhanced soluble expression of recombinant reteplase, and up to 60% of reteplase achieved soluble expression especially for the DsbC co-expression system. The fibrin plate method for active reteplase quantification showed that ∼70 mg soluble reteplase per liter fermentation broth was obtained with 2.35 × 105 IU/mg thrombolytic activity. Finally, fluorescence spectra indicated that the structural conformation of soluble reteplase was identical to its native state. The soluble expression of recombinant reteplase in E. coli was accomplished by co-expression with DsbA/DsbC, which contributes to further research in clinical application and folding mechanism, and provides guidance for production of other proteins with disulfide bonds.
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31
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Wimmer MR, Woods CN, Adamczak KJ, Glasgow EM, Novak WRP, Grilley DP, Weaver TM. Sequential unfolding of the hemolysin two-partner secretion domain from Proteus mirabilis. Protein Sci 2015; 24:1841-55. [PMID: 26350294 DOI: 10.1002/pro.2791] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 08/19/2015] [Accepted: 08/20/2015] [Indexed: 01/07/2023]
Abstract
Protein secretion is a major contributor to Gram-negative bacterial virulence. Type Vb or two-partner secretion (TPS) pathways utilize a membrane bound β-barrel B component (TpsB) to translocate large and predominantly virulent exoproteins (TpsA) through a nucleotide independent mechanism. We focused our studies on a truncated TpsA member termed hemolysin A (HpmA265), a structurally and functionally characterized TPS domain from Proteus mirabilis. Contrary to the expectation that the TPS domain of HpmA265 would denature in a single cooperative transition, we found that the unfolding follows a sequential model with three distinct transitions linking four states. The solvent inaccessible core of HpmA265 can be divided into two different regions. The C-proximal region contains nonpolar residues and forms a prototypical hydrophobic core as found in globular proteins. The N-proximal region of the solvent inaccessible core, however, contains polar residues. To understand the contributions of the hydrophobic and polar interiors to overall TPS domain stability, we conducted unfolding studies on HpmA265 and site-specific mutants of HpmA265. By correlating the effect of individual site-specific mutations with the sequential unfolding results we were able to divide the HpmA265 TPS domain into polar core, nonpolar core, and C-terminal subdomains. Moreover, the unfolding studies provide quantitative evidence that the folding free energy for the polar core subdomain is more favorable than for the nonpolar core and C-terminal subdomains. This study implicates the hydrogen bonds shared among these conserved internal residues as a primary means for stabilizing the N-proximal polar core subdomain.
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Affiliation(s)
- Megan R Wimmer
- Department of Chemistry and Biochemistry, University Wisconsin - La Crosse, La Crosse, Wisconsin, 54601
| | - Christopher N Woods
- Department of Chemistry and Biochemistry, University Wisconsin - La Crosse, La Crosse, Wisconsin, 54601
| | - Kyle J Adamczak
- Department of Chemistry and Biochemistry, University Wisconsin - La Crosse, La Crosse, Wisconsin, 54601
| | - Evan M Glasgow
- Department of Chemistry and Biochemistry, University Wisconsin - La Crosse, La Crosse, Wisconsin, 54601
| | - Walter R P Novak
- Department of Chemistry, Wabash College, Crawfordsville, Indiana, 47933
| | - Daniel P Grilley
- Department of Chemistry and Biochemistry, University Wisconsin - La Crosse, La Crosse, Wisconsin, 54601
| | - Todd M Weaver
- Department of Chemistry and Biochemistry, University Wisconsin - La Crosse, La Crosse, Wisconsin, 54601
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32
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Um SH, Kim JS, Song S, Kim NA, Jeong SH, Ha NC. Crystal Structure of DsbA from Corynebacterium diphtheriae and Its Functional Implications for CueP in Gram-Positive Bacteria. Mol Cells 2015; 38:715-22. [PMID: 26082031 PMCID: PMC4546943 DOI: 10.14348/molcells.2015.0099] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 05/07/2015] [Accepted: 05/11/2015] [Indexed: 01/31/2023] Open
Abstract
In Gram-negative bacteria in the periplasmic space, the dimeric thioredoxin-fold protein DsbC isomerizes and reduces incorrect disulfide bonds of unfolded proteins, while the monomeric thioredoxin-fold protein DsbA introduces disulfide bonds in folding proteins. In the Gram-negative bacteria Salmonella enterica serovar Typhimurium, the reduced form of CueP scavenges the production of hydroxyl radicals in the copper-mediated Fenton reaction, and DsbC is responsible for keeping CueP in the reduced, active form. Some DsbA proteins fulfill the functions of DsbCs, which are not present in Gram-positive bacteria. In this study, we identified a DsbA homologous protein (CdDsbA) in the Corynebacterium diphtheriae genome and determined its crystal structure in the reduced condition at 1.5 Å resolution. CdDsbA consists of a monomeric thioredoxin-like fold with an inserted helical domain and unique N-terminal extended region. We confirmed that CdDsbA has disulfide bond isomerase/reductase activity, and we present evidence that the N-terminal extended region is not required for this activity and folding of the core DsbA-like domain. Furthermore, we found that CdDsbA could reduce CueP from C. diphtheriae.
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Affiliation(s)
- Si-Hyeon Um
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 151-921, Korea
| | - Jin-Sik Kim
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 151-921, Korea
| | - Saemee Song
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 151-921, Korea
| | - Nam Ah Kim
- College of Pharmacy, Dongguk University-Seoul, Goyang 410-820, Korea
| | - Seong Hoon Jeong
- College of Pharmacy, Dongguk University-Seoul, Goyang 410-820, Korea
| | - Nam-Chul Ha
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 151-921, Korea
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33
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Loh Q, Leong SW, Tye GJ, Choong YS, Lim TS. Improved Fab presentation on phage surface with the use of molecular chaperone coplasmid system. Anal Biochem 2015; 477:56-61. [PMID: 25769419 DOI: 10.1016/j.ab.2015.02.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 02/24/2015] [Accepted: 02/24/2015] [Indexed: 11/29/2022]
Abstract
The low presentation efficiency of Fab (fragment antigen binding) fragments during phage display is largely due to the complexity of disulphide bond formation. This can result in the presentation of Fab fragments devoid of a light chain during phage display. Here we propose the use of a coplasmid system encoding several molecular chaperones (DsbA, DsbC, FkpA, and SurA) to improve Fab packaging. A comparison was done using the Fab fragment from IgG and IgD. We found that the use of the coplasmid during phage packaging was able to improve the presentation efficiency of the Fab fragment on phage surfaces. A modified version of panning using the coplasmid system was evaluated and was successful at enriching Fab binders. Therefore, the coplasmid system would be an attractive alternative for improved Fab presentation for phage display.
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Affiliation(s)
- Qiuting Loh
- Institute for Research in Molecular Medicine, University Sains Malaysia, 11800 Penang, Malaysia
| | - Siew Wen Leong
- Institute for Research in Molecular Medicine, University Sains Malaysia, 11800 Penang, Malaysia
| | - Gee Jun Tye
- Institute for Research in Molecular Medicine, University Sains Malaysia, 11800 Penang, Malaysia
| | - Yee Siew Choong
- Institute for Research in Molecular Medicine, University Sains Malaysia, 11800 Penang, Malaysia
| | - Theam Soon Lim
- Institute for Research in Molecular Medicine, University Sains Malaysia, 11800 Penang, Malaysia.
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34
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Patil NA, Tailhades J, Hughes RA, Separovic F, Wade JD, Hossain MA. Cellular disulfide bond formation in bioactive peptides and proteins. Int J Mol Sci 2015; 16:1791-805. [PMID: 25594871 PMCID: PMC4307334 DOI: 10.3390/ijms16011791] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/02/2015] [Indexed: 11/16/2022] Open
Abstract
Bioactive peptides play important roles in metabolic regulation and modulation and many are used as therapeutics. These peptides often possess disulfide bonds, which are important for their structure, function and stability. A systematic network of enzymes--a disulfide bond generating enzyme, a disulfide bond donor enzyme and a redox cofactor--that function inside the cell dictates the formation and maintenance of disulfide bonds. The main pathways that catalyze disulfide bond formation in peptides and proteins in prokaryotes and eukaryotes are remarkably similar and share several mechanistic features. This review summarizes the formation of disulfide bonds in peptides and proteins by cellular and recombinant machinery.
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Affiliation(s)
- Nitin A Patil
- Florey Institute of Neuroscience and Mental Health, the University of Melbourne, Victoria 3010, Australia.
| | - Julien Tailhades
- Florey Institute of Neuroscience and Mental Health, the University of Melbourne, Victoria 3010, Australia.
| | - Richard Anthony Hughes
- Department of Pharmacology and Therapeutics, the University of Melbourne, Victoria 3010, Australia.
| | - Frances Separovic
- School of Chemistry, the University of Melbourne, Victoria 3010, Australia.
| | - John D Wade
- Florey Institute of Neuroscience and Mental Health, the University of Melbourne, Victoria 3010, Australia.
| | - Mohammed Akhter Hossain
- Florey Institute of Neuroscience and Mental Health, the University of Melbourne, Victoria 3010, Australia.
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35
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Hemmis CW, Wright NT, Majumdar A, Schildbach JF. Chemical shift assignments of a reduced N-terminal truncation mutant of the disulfide bond isomerase TrbB from plasmid F, TrbBΔ29. BIOMOLECULAR NMR ASSIGNMENTS 2014; 8:435-438. [PMID: 24771093 PMCID: PMC4268134 DOI: 10.1007/s12104-013-9533-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Accepted: 12/12/2013] [Indexed: 06/03/2023]
Abstract
TrbB from the conjugative plasmid F is a 181-residue disulfide bond isomerase that plays a role in the correct folding and maintenance of disulfide bonds within F plasmid encoded proteins in the bacterial periplasm. As a member of the thioredoxin-like superfamily, TrbB has a predicted thioredoxin-like fold that contains a C-X-X-C active site required for performing specific redox chemistries on protein substrates. Here we report the sequence-specific assignments of the reduced form of the N-terminally truncated TrbB construct, TrbBΔ29.
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Affiliation(s)
- Casey W. Hemmis
- Department of Biology, The Johns Hopkins University, Baltimore, Maryland 21218
| | - Nathan T. Wright
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia 22807
| | - Ananya Majumdar
- Department of Biology, The Johns Hopkins University, Baltimore, Maryland 21218
| | - Joel F. Schildbach
- Department of Biology, The Johns Hopkins University, Baltimore, Maryland 21218
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36
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The disulfide bonding system suppresses CsgD-independent cellulose production in Escherichia coli. J Bacteriol 2014; 196:3690-9. [PMID: 25112475 DOI: 10.1128/jb.02019-14] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The bacterial extracellular matrix encases cells and protects them from host-related and environmental insults. The Escherichia coli master biofilm regulator CsgD is required for the production of the matrix components curli and cellulose. CsgD activates the diguanylate cyclase AdrA, which in turn stimulates cellulose production through cyclic di-GMP (c-di-GMP). Here, we identified and characterized a CsgD- and AdrA-independent cellulose production pathway that was maximally active when cultures were grown under reducing conditions or when the disulfide bonding system (DSB) was compromised. The CsgD-independent cellulose activation pathway was dependent on a second diguanylate cyclase, called YfiN. c-di-GMP production by YfiN was repressed by the periplasmic protein YfiR, and deletion of yfiR promoted CsgD-independent cellulose production. Conversely, when YfiR was overexpressed, cellulose production was decreased. Finally, we found that YfiR was oxidized by DsbA and that intraprotein YfiR disulfide bonds stabilized YfiR in the periplasm. Altogether, we showed that reducing conditions and mutations in the DSB system caused hyperactivation of YfiN and subsequent CsgD-independent cellulose production.
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37
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Van Gerven N, Goyal P, Vandenbussche G, De Kerpel M, Jonckheere W, De Greve H, Remaut H. Secretion and functional display of fusion proteins through the curli biogenesis pathway. Mol Microbiol 2014; 91:1022-35. [PMID: 24417346 DOI: 10.1111/mmi.12515] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/09/2014] [Indexed: 01/04/2023]
Abstract
Curli are functional amyloids expressed as fibres on the surface of Enterobacteriaceae. Contrary to the protein misfolding events associated with pathogenic amyloidosis, curli are the result of a dedicated biosynthetic pathway. A specialized transporter in the outer membrane, CsgG, operates in conjunction with the two accessory proteins CsgE and CsgF to secrete curlin subunits to the extracellular surface, where they nucleate into cross-beta strand fibres. Here we investigate the substrate tolerance of the CsgG transporter and the capability of heterologous sequences to be built into curli fibres. Non-native polypeptides ranging up to at least 260 residues were exported when fused to the curli subunit CsgA. Secretion efficiency depended on the folding properties of the passenger sequences, with substrates exceeding an approximately 2 nm transverse diameter blocking passage through the transport channel. Secretion of smaller passengers was compatible with prior DsbA-mediated disulphide bridge formation in the fusion partner, indicating that CsgG is capable of translocating non-linear polypeptide stretches. Using fusions we further demonstrate the exported or secreted heterologous passenger proteins can attain their native, active fold, establishing curli biogenesis pathway as a platform for the secretion and surface display of small heterologous proteins.
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Affiliation(s)
- Nani Van Gerven
- Structural & Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050, Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
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38
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Israel BA, Kodali VK, Thorpe C. Going through the barrier: coupled disulfide exchange reactions promote efficient catalysis in quiescin sulfhydryl oxidase. J Biol Chem 2013; 289:5274-84. [PMID: 24379406 DOI: 10.1074/jbc.m113.536219] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The quiescin sulfhydryl oxidase (QSOX) family of enzymes generates disulfide bonds in peptides and proteins with the reduction of oxygen to hydrogen peroxide. Determination of the potentials of the redox centers in Trypanosoma brucei QSOX provides a context for understanding catalysis by this facile oxidant of protein thiols. The CXXC motif of the thioredoxin domain is comparatively oxidizing (E'0 of -144 mV), consistent with an ability to transfer disulfide bonds to a broad range of thiol substrates. In contrast, the proximal CXXC disulfide in the ERV (essential for respiration and vegetative growth) domain of TbQSOX is strongly reducing (E'0 of -273 mV), representing a major apparent thermodynamic barrier to overall catalysis. Reduction of the oxidizing FAD cofactor (E'0 of -153 mV) is followed by the strongly favorable reduction of molecular oxygen. The role of a mixed disulfide intermediate between thioredoxin and ERV domains was highlighted by rapid reaction studies in which the wild-type CGAC motif in the thioredoxin domain of TbQSOX was replaced by the more oxidizing CPHC or more reducing CGPC sequence. Mixed disulfide bond formation is accompanied by the generation of a charge transfer complex with the flavin cofactor. This provides thermodynamic coupling among the three redox centers of QSOX and avoids the strongly uphill mismatch between the formal potentials of the thioredoxin and ERV disulfides. This work identifies intriguing mechanistic parallels between the eukaryotic QSOX enzymes and the DsbA/B system catalyzing disulfide bond generation in the bacterial periplasm and suggests that the strategy of linked disulfide exchanges may be exploited in other catalysts of oxidative protein folding.
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Affiliation(s)
- Benjamin A Israel
- From the Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716
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Góngora-Benítez M, Tulla-Puche J, Albericio F. Multifaceted Roles of Disulfide Bonds. Peptides as Therapeutics. Chem Rev 2013; 114:901-26. [DOI: 10.1021/cr400031z] [Citation(s) in RCA: 388] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Miriam Góngora-Benítez
- Institute
for Research in Biomedicine (IRB Barcelona), Barcelona, 08028 Spain
- CIBER-BBN, Barcelona Science
Park, Barcelona, 08028 Spain
| | - Judit Tulla-Puche
- Institute
for Research in Biomedicine (IRB Barcelona), Barcelona, 08028 Spain
- CIBER-BBN, Barcelona Science
Park, Barcelona, 08028 Spain
| | - Fernando Albericio
- Institute
for Research in Biomedicine (IRB Barcelona), Barcelona, 08028 Spain
- CIBER-BBN, Barcelona Science
Park, Barcelona, 08028 Spain
- Department
of Organic Chemistry, University of Barcelona, Barcelona, 08028 Spain
- School of Chemistry & Physics, University of KwaZulu-Natal, 4001 Durban, South Africa
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40
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Souza GS, do Nascimento VV, de Carvalho LP, de Melo EJT, Fernandes KV, Machado OLT, Retamal CA, Gomes VM, Carvalho ADO. Activity of recombinant and natural defensins from Vigna unguiculata seeds against Leishmania amazonensis. Exp Parasitol 2013; 135:116-25. [DOI: 10.1016/j.exppara.2013.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 05/27/2013] [Accepted: 06/12/2013] [Indexed: 01/18/2023]
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41
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Jalalirad R. Selective and efficient extraction of recombinant proteins from the periplasm of Escherichia coli using low concentrations of chemicals. J Ind Microbiol Biotechnol 2013; 40:1117-29. [PMID: 23864192 DOI: 10.1007/s10295-013-1307-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Accepted: 06/19/2013] [Indexed: 11/28/2022]
Abstract
Experiments were conducted to determine chemicals at low concentrations, which can be utilized for selective release of periplasmic proteins. It was revealed that 80-100 % of the activity of alpha-amylase, beta-lactamase, and Fab D1.3 was retained in the presence of 0.05 and 0.1 % Triton X-100, 0.1 % Tween 20, 0.1 % DOC, 0.01 % BAC, 0.01 % CTAB, 10 mM EDTA, 1 mM and 10 mM DEA, 10 mM NTA, 0.1 and 1 % SHMP, 200 mM urea, 100-500 mM GndCl, and 1 % solvents (hexane, xylene, toluene, benzene, pyridine and isoamyl alcohol). Performance of these chemicals, recognized as generally safe, for selective release of proteins from the periplasm of Escherichia coli was investigated. DOC was a general and very efficient agent, and at concentrations as low as 0.05, 0.1, and 0.025 %, released beta-lactamase, alpha-amylase, and Fab D1.3 selectively with yield factors of 2.7, 2.3, and 3.6 times greater than osmotic shock procedure, respectively. EDTA (1 and 10 mM) discharged Fab D1.3 with efficiency more than osmotic shock (target protein yield of 110 and 138 %, correspondingly). Isoamyl alcohol (10 % v/v) was effective for periplasmic release of alpha-amylase and particularly Fab D1.3, with target protein yields of 75 and 168 %, respectively.
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Affiliation(s)
- Reza Jalalirad
- School of Chemical Engineering, College of Engineering and Physical Sciences, The University of Birmingham, Edgbaston, B15 2TT, UK,
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Hemmis CW, Schildbach JF. Thioredoxin-like proteins in F and other plasmid systems. Plasmid 2013; 70:168-89. [PMID: 23721857 DOI: 10.1016/j.plasmid.2013.05.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 05/12/2013] [Accepted: 05/13/2013] [Indexed: 11/29/2022]
Abstract
Bacterial conjugation is the process by which a conjugative plasmid transfers from donor to recipient bacterium. During this process, single-stranded plasmid DNA is actively and specifically transported from the cytoplasm of the donor, through a large membrane-spanning assembly known as the pore complex, and into the cytoplasm of the recipient. In Gram negative bacteria, construction of the pore requires localization of a subset of structural and catalytically active proteins to the bacterial periplasm. Unlike the cytoplasm, the periplasm contains proteins that promote disulfide bond formation within or between cysteine-containing proteins. To ensure proper protein folding and assembly, bacteria employ periplasmic redox systems for thiol oxidation, disulfide bond/sulfenic acid reduction, and disulfide bond isomerization. Recent data suggest that plasmid-based proteins belonging to the disulfide bond formation family play an integral role in the conjugative process by serving as mediators in folding and/or assembly of pore complex proteins. Here we report the identification of 165 thioredoxin-like family members across 89 different plasmid systems. Using phylogenetic analysis, all but nine family members were categorized into thioredoxin-like subfamilies. In addition, we discuss the diversity, conservation, and putative roles of thioredoxin-like proteins in plasmid systems, which include homologs of DsbA, DsbB, DsbC, DsbD, DsbG, and CcmG from Escherichia coli, TlpA from Bradyrhizobium japonicum, Com1 from Coxiella burnetii, as well as TrbB and TraF from plasmid F, and the absolute conservation of a disulfide isomerase in plasmids containing homologs of the transfer proteins TraH, TraN, and TraU.
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Affiliation(s)
- Casey W Hemmis
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
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Abstract
Protein action in nature is largely controlled by the level of expression and by post-translational modifications. Post-translational modifications result in a proteome that is at least two orders of magnitude more diverse than the genome. There are three basic types of post-translational modifications: covalent modification of an amino acid side chain, hydrolytic cleavage or isomerization of a peptide bond, and reductive cleavage of a disulfide bond. This review addresses the modification of disulfide bonds. Protein disulfide bonds perform either a structural or a functional role, and there are two types of functional disulfide: the catalytic and allosteric bonds. The allosteric disulfide bonds control the function of the mature protein in which they reside by triggering a change when they are cleaved. The change can be in ligand binding, substrate hydrolysis, proteolysis, or oligomer formation. The allosteric disulfides are cleaved by oxidoreductases or by thiol/disulfide exchange, and the configurations of the disulfides and the secondary structures that they link share some recurring features. How these bonds are being identified using bioinformatics and experimental screens and what the future holds for this field of research are also discussed.
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Affiliation(s)
- Kristina M Cook
- Lowy Cancer Research Centre and Prince of Wales Clinical School, University of New South Wales, Sydney NSW2052, Australia
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Production of functional antibody fragments in a vesicle-based eukaryotic cell-free translation system. J Biotechnol 2012; 164:220-31. [PMID: 22982167 DOI: 10.1016/j.jbiotec.2012.08.020] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 08/15/2012] [Accepted: 08/30/2012] [Indexed: 12/17/2022]
Abstract
Cell-free protein synthesis is of increasing interest for the rapid and high-throughput synthesis of many proteins, in particular also antibody fragments. In this study, we present a novel strategy for the production of single chain antibody fragments (scFv) in a eukaryotic in vitro translation system. This strategy comprises the cell-free expression, isolation and label-free interaction analysis of a model antibody fragment synthesized in two differently prepared insect cell lysates. These lysates contain translocationally active microsomal structures derived from the endoplasmic reticulum (ER), allowing for posttranslational modifications of cell-free synthesized proteins. Both types of these insect cell lysates enable the synthesis and translocation of scFv into ER-derived vesicles. However, only the one that has a specifically adapted redox potential yields functional active antibody fragments. We have developed a new methodology for the isolation of functional target proteins based on the translocation of cell-free produced scFv into microsomal structures and subsequent collection of protein-enriched vesicles. Antibody fragments that have been released from these vesicles are shown to be well suited for label-free binding studies. Altogether, these results show the potential of insect cell lysates for the production, purification and selection of antibody fragments in an easy-to-handle and time-saving manner.
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Haque SJ, Majumdar T, Barik S. Redox-assisted protein folding systems in eukaryotic parasites. Antioxid Redox Signal 2012; 17:674-83. [PMID: 22122448 PMCID: PMC3373220 DOI: 10.1089/ars.2011.4433] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
SIGNIFICANCE The cysteine (Cys) residues of proteins play two fundamentally important roles. They serve as sites of post-translational redox modifications as well as influence the conformation of the protein through the formation of disulfide bonds. RECENT ADVANCES Redox-related and redox-associated protein folding in protozoan parasites has been found to be a major mode of regulation, affecting myriad aspects of the parasitic life cycle, host-parasite interactions, and the disease pathology. Available genome sequences of various parasites have begun to complement the classical biochemical and enzymological studies of these processes. In this article, we summarize the reversible Cys disulfide (S-S) bond formation in various classes of strategically important parasitic proteins, and its structural consequence and functional relevance. CRITICAL ISSUES Molecular mechanisms of folding remain under-studied and often disconnected from functional relevance. FUTURE DIRECTIONS The clinical benefit of redox research will require a comprehensive characterization of the various isoforms and paralogs of the redox enzymes and their concerted effect on the structure and function of the specific parasitic client proteins.
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Affiliation(s)
- Saikh Jaharul Haque
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
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Malojčić G, Geertsma ER, Brozzo MS, Glockshuber R. Mechanism of the Prokaryotic Transmembrane Disulfide Reduction Pathway and Its In Vitro Reconstitution from Purified Components. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201201337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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47
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Entzminger KC, Chang C, Myhre RO, McCallum KC, Maynard JA. The Skp chaperone helps fold soluble proteins in vitro by inhibiting aggregation. Biochemistry 2012; 51:4822-34. [PMID: 22650963 DOI: 10.1021/bi300412y] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The periplasmic seventeen kilodalton protein (Skp) chaperone has been characterized primarily for its role in outer membrane protein (OMP) biogenesis, during which the jellyfish-like trimeric protein encapsulates partially folded OMPs, protecting them from the aqueous environment until delivery to the BAM outer membrane protein insertion complex. However, Skp is increasingly recognized as a chaperone that also assists in folding soluble proteins in the bacterial periplasm. In this capacity, Skp coexpression increases the active yields of many recombinant proteins and bacterial virulence factors. Using a panel of single-chain antibodies and a single-chain T-cell receptor (collectively termed scFvs) possessing varying stabilities and biophysical characteristics, we performed in vivo expression and in vitro folding and aggregation assays in the presence or absence of Skp. For Skp-sensitive scFvs, the presence of Skp during in vitro refolding assays reduced aggregation but did not alter the observed folding rates, resulting in a higher overall yield of active protein. Of the proteins analyzed, Skp sensitivity in all assays correlated with the presence of folding intermediates, as observed with urea denaturation studies. These results are consistent with Skp acting as a holdase, sequestering partially folded intermediates and thereby preventing aggregation. Because not all soluble proteins are sensitive to Skp coexpression, we hypothesize that the presence of a long-lived protein folding intermediate renders a protein sensitive to Skp. Improved understanding of the bacterial periplasmic protein folding machinery may assist in high-level recombinant protein expression and may help identify novel approaches to block bacterial virulence.
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Affiliation(s)
- Kevin C Entzminger
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
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Malojčić G, Geertsma ER, Brozzo MS, Glockshuber R. Mechanism of the prokaryotic transmembrane disulfide reduction pathway and its in vitro reconstitution from purified components. Angew Chem Int Ed Engl 2012; 51:6900-3. [PMID: 22674494 DOI: 10.1002/anie.201201337] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Indexed: 01/23/2023]
Abstract
Making your (Dsb) connection: the redox pathway bringing reducing equivalents from bacterial cytoplasm, across the inner membrane, to the three reductive Dsb pathways in the otherwise oxidizing periplasm (see scheme; TR=thioredoxin reductase, Trx=thioredoxin) is reconstituted from purified components. Transfer of reducing equivalents across the membrane is demonstrated and underlying mechanistic details are revealed.
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Affiliation(s)
- Goran Malojčić
- Institute for Molecular Biology and Biophysics, ETH Zurich, Switzerland.
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49
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Steiner AM, Woycechowsky KJ, Olivera BM, Bulaj G. Reagentless Oxidative Folding of Disulfide-Rich Peptides Catalyzed by an Intramolecular Diselenide. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201200062] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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50
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Steiner AM, Woycechowsky KJ, Olivera BM, Bulaj G. Reagentless oxidative folding of disulfide-rich peptides catalyzed by an intramolecular diselenide. Angew Chem Int Ed Engl 2012; 51:5580-4. [PMID: 22454362 DOI: 10.1002/anie.201200062] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 03/03/2012] [Indexed: 11/08/2022]
Affiliation(s)
- Andrew M Steiner
- Department of Medicinal Chemistry, University of Utah, 421 Wakara Way, Suite 360, Salt Lake City, UT 84108, USA
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