1
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He F, Wang J, Yuan D, Liu Y, Liu R, Zong W. Ferric ions release from iron-binding protein: Interaction between acrylamide and human serum transferrin and the underlying mechanisms of their binding. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 847:157583. [PMID: 35882343 DOI: 10.1016/j.scitotenv.2022.157583] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/17/2022] [Accepted: 07/19/2022] [Indexed: 06/15/2023]
Abstract
Acrylamide (ACR) is a surprisingly common chemical due to its widespread use in industry and various other applications. However, its toxicity is a matter of grave concern for public health. Even worse, ACR is frequently detected in numerous fried or baked carbohydrate-rich foods due to the Maillard browning reaction. Herein, this study intends to delineate the underlying molecular mechanisms of Fe ions released from iron-binding protein transferrin (TF) after acrylamide binding by combining multiple methods, including multiple complementary spectroscopic techniques (UV-Vis, fluorescence, and circular dichroism spectroscopy), isothermal titration calorimetry, ICP-MS measurements, and modeling simulations. Results indicated that free Fe was released from TF only under high-dose ACR exposure (>100 μM). Acrylamide binding induced the loosening and unfolding of the backbone and polypeptide chain and destroyed the secondary structure of TF, thereby leading to protein misfolding and denaturation of TF and forming a larger size of TF agglomerates. Of which, H-binding and van der Waals force are the primary driving force during the binding interaction between ACR and TF. Further modeling simulations illustrated that ACR prefers to bind to the hinge region connecting the C-lobe and N-lobe, after that it attaches to the Fe binding sites of this protein, which is the cause of free Fe release from TF. Moreover, ACR interacted with the critical fluorophore residues (Tyr, Trp, and Phe) in the binding pocket, which might explain such a phenomenon of fluorescence sensitization. The two binding sites (Site 2 and Site 3) located around the Fe (III) ions with low-energy conformations are more suitable for ACR binding. Collectively, our study demonstrated that the loss of iron in TF caused by acrylamide-induced structural and conformational changes of transferrin.
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Affiliation(s)
- Falin He
- School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, 72# Jimo Binhai Road, Qingdao, Shandong 266237, PR China
| | - Jinhu Wang
- College of Chemistry, Chemical Engineering and Material Science, Zaozhuang University, Zaozhuang, Shandong 277160, PR China
| | - Dong Yuan
- Department of Chemistry and Chemical Engineering, Qilu Normal University, Jinan 250013, PR China.
| | - Yang Liu
- Department of Chemistry and Chemical Engineering, Qilu Normal University, Jinan 250013, PR China
| | - Rutao Liu
- School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, 72# Jimo Binhai Road, Qingdao, Shandong 266237, PR China.
| | - Wansong Zong
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan, Shandong 250014, PR China
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2
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Ziemianowicz DS, Ng D, Schryvers AB, Schriemer DC. Photo-Cross-Linking Mass Spectrometry and Integrative Modeling Enables Rapid Screening of Antigen Interactions Involving Bacterial Transferrin Receptors. J Proteome Res 2018; 18:934-946. [DOI: 10.1021/acs.jproteome.8b00629] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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3
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Guizzo JA, Chaudhuri S, Prigol SR, Yu RH, Dazzi CC, Balbinott N, Frandoloso GP, Kreutz LC, Frandoloso R, Schryvers AB. The amino acid selected for generating mutant TbpB antigens defective in binding transferrin can compromise the in vivo protective capacity. Sci Rep 2018; 8:7372. [PMID: 29743502 PMCID: PMC5943581 DOI: 10.1038/s41598-018-25685-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/26/2018] [Indexed: 02/08/2023] Open
Abstract
Haemophilus parasuis is the causative agent of the Glässer's disease (GD), one of the most important bacterial diseases that affect young pigs worldwide. GD prevention based on vaccination is a major concern due to the limited cross-protection conferred by the inactivated whole cell vaccines used currently. In this study, vaccines based on two mutant recombinant proteins derived from transferrin binding protein B of H. parasuis (Y167A-TbpB and W176A-TbpB) were formulated and evaluated in terms of protection against lethal challenge using a serovar 7 (SV7) H. parasuis in a high susceptibility pig model. Our results showed that H. parasuis strain 174 (SV7) is highly virulent in conventional and colostrum-deprived pigs. The Y167A-TbpB and W176A-TbpB antigens were immunogenic in pigs, however, differences in terms of antigenicity and functional immune response were observed. In regard to protection, animals immunized with Y167A-TbpB antigen displayed 80% survival whereas the W176A-TbpB protein was not protective. In conjunction with previous studies, our results demonstrate, (a) the importance of testing engineered antigens in an in vivo pig challenge model, and, (b) that the Y167A-TbpB antigen is a promising antigen for developing a broad-spectrum vaccine against H. parasuis infection.
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Affiliation(s)
- João Antônio Guizzo
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil
| | - Somshukla Chaudhuri
- Department of Microbiology & Infectious Diseases, Faculty of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
| | - Simone Ramos Prigol
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil
| | - Rong-Hua Yu
- Department of Microbiology & Infectious Diseases, Faculty of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
| | - Cláudia Cerutti Dazzi
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil
| | - Natalia Balbinott
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil
| | - Gabriela Paraboni Frandoloso
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil
| | - Luiz Carlos Kreutz
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil
| | - Rafael Frandoloso
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil.
| | - Anthony Bernard Schryvers
- Department of Microbiology & Infectious Diseases, Faculty of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada.
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4
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Barasuol BM, Guizzo JA, Fegan JE, Martínez-Martínez S, Rodríguez-Ferri EF, Gutiérrez-Martín CB, Kreutz LC, Schryvers AB, Frandoloso R. New insights about functional and cross-reactive properties of antibodies generated against recombinant TbpBs of Haemophilus parasuis. Sci Rep 2017; 7:10377. [PMID: 28871190 PMCID: PMC5583350 DOI: 10.1038/s41598-017-10627-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 08/10/2017] [Indexed: 12/20/2022] Open
Abstract
Vaccines have become fundamental in the control and elimination of Glässer Disease, a systemic disease of pigs caused by Haemophilus parasuis. The classic vaccines available for prevention of this infection were developed without a robust knowledge about host immunological mechanisms. In this study, we demonstrated the presence of cross-reactive epitopes on both the N-lobe and C-lobe of variants of transferrin binding protein B (TbpBs) expressed on the surface of 6 virulent serovars of H. parasuis. Antibodies against TbpB-derived antigens were capable of increasing the phagocytic capacity of neutrophils and were also capable of blocking porcine transferrin from binding to TbpB. Surprisingly, none of the pig or mice antisera from animals immunized with TbpB-derived antigens mixed with Montanide IMS 2215 VG PR adjuvant were able to activate the classical complement pathway (CCP). In contrast, antisera from mice immunized with TbpB-derived antigens adjuvanted with Freund’s adjuvants or Montanide Gel 01 were able to activate the CCP and kill H. parasuis. Our results demonstrate that the type of adjuvant can modulate the functional response induced by TbpB-derived antigens. Based on these results, we propose that a properly formulated TbpB-based vaccine may elicit a functional protective antibody response with broad cross-reactivity against heterologous strains of H. parasuis.
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Affiliation(s)
- Bibiana Martins Barasuol
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil
| | - João Antônio Guizzo
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil
| | - Jamie Elisabeth Fegan
- Department of Microbiology & Infectious Diseases, Faculty of Medicine, University of Calgary, Calgary, T2N 4N1, Alberta, Canada
| | - Sonia Martínez-Martínez
- Unidad de Microbiología e Inmunología, Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, 24007, León, Spain
| | - Elías Fernando Rodríguez-Ferri
- Unidad de Microbiología e Inmunología, Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, 24007, León, Spain
| | - César Bernardo Gutiérrez-Martín
- Unidad de Microbiología e Inmunología, Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, 24007, León, Spain
| | - Luiz Carlos Kreutz
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil
| | - Anthony Bernard Schryvers
- Department of Microbiology & Infectious Diseases, Faculty of Medicine, University of Calgary, Calgary, T2N 4N1, Alberta, Canada
| | - Rafael Frandoloso
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil.
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5
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Ostan NKH, Yu RH, Ng D, Lai CCL, Pogoutse AK, Sarpe V, Hepburn M, Sheff J, Raval S, Schriemer DC, Moraes TF, Schryvers AB. Lactoferrin binding protein B - a bi-functional bacterial receptor protein. PLoS Pathog 2017; 13:e1006244. [PMID: 28257520 PMCID: PMC5352143 DOI: 10.1371/journal.ppat.1006244] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 03/15/2017] [Accepted: 02/15/2017] [Indexed: 11/18/2022] Open
Abstract
Lactoferrin binding protein B (LbpB) is a bi-lobed outer membrane-bound lipoprotein that comprises part of the lactoferrin (Lf) receptor complex in Neisseria meningitidis and other Gram-negative pathogens. Recent studies have demonstrated that LbpB plays a role in protecting the bacteria from cationic antimicrobial peptides due to large regions rich in anionic residues in the C-terminal lobe. Relative to its homolog, transferrin-binding protein B (TbpB), there currently is little evidence for its role in iron acquisition and relatively little structural and biophysical information on its interaction with Lf. In this study, a combination of crosslinking and deuterium exchange coupled to mass spectrometry, information-driven computational docking, bio-layer interferometry, and site-directed mutagenesis was used to probe LbpB:hLf complexes. The formation of a 1:1 complex of iron-loaded Lf and LbpB involves an interaction between the Lf C-lobe and LbpB N-lobe, comparable to TbpB, consistent with a potential role in iron acquisition. The Lf N-lobe is also capable of binding to negatively charged regions of the LbpB C-lobe and possibly other sites such that a variety of higher order complexes are formed. Our results are consistent with LbpB serving dual roles focused primarily on iron acquisition when exposed to limited levels of iron-loaded Lf on the mucosal surface and effectively binding apo Lf when exposed to high levels at sites of inflammation.
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Affiliation(s)
- Nicholas K. H. Ostan
- Department of Microbiology & Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Rong-Hua Yu
- Department of Microbiology & Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Dixon Ng
- Department of Microbiology & Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | | | | | - Vladimir Sarpe
- Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada
| | - Morgan Hepburn
- Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada
| | - Joey Sheff
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada
| | - Shaunak Raval
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada
| | - David C. Schriemer
- Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada
| | - Trevor F. Moraes
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Anthony B. Schryvers
- Department of Microbiology & Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada
- * E-mail:
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6
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Sarpe V, Rafiei A, Hepburn M, Ostan N, Schryvers AB, Schriemer DC. High Sensitivity Crosslink Detection Coupled With Integrative Structure Modeling in the Mass Spec Studio. Mol Cell Proteomics 2016; 15:3071-80. [PMID: 27412762 DOI: 10.1074/mcp.o116.058685] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Indexed: 01/21/2023] Open
Abstract
The Mass Spec Studio package was designed to support the extraction of hydrogen-deuterium exchange and covalent labeling data for a range of mass spectrometry (MS)-based workflows, to integrate with restraint-driven protein modeling activities. In this report, we present an extension of the underlying Studio framework and provide a plug-in for crosslink (XL) detection. To accommodate flexibility in XL methods and applications, while maintaining efficient data processing, the plug-in employs a peptide library reduction strategy via a presearch of the tandem-MS data. We demonstrate that prescoring linear unmodified peptide tags using a probabilistic approach substantially reduces search space by requiring both crosslinked peptides to generate sparse data attributable to their linear forms. The method demonstrates highly sensitive crosslink peptide identification with a low false positive rate. Integration with a Haddock plug-in provides a resource that can combine multiple sources of data for protein modeling activities. We generated a structural model of porcine transferrin bound to TbpB, a membrane-bound receptor essential for iron acquisition in Actinobacillus pleuropneumoniae Using mutational data and crosslinking restraints, we confirm the mechanism by which TbpB recognizes the iron-loaded form of transferrin, and note the requirement for disparate sources of restraint data for accurate model construction. The software plugin is freely available at www.msstudio.ca.
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Affiliation(s)
- Vladimir Sarpe
- From the ‡Department of Biochemistry and Molecular Biology
| | | | - Morgan Hepburn
- From the ‡Department of Biochemistry and Molecular Biology
| | - Nicholas Ostan
- ¶Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Alberta, T2N 1N4, Canada
| | - Anthony B Schryvers
- From the ‡Department of Biochemistry and Molecular Biology, ¶Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Alberta, T2N 1N4, Canada
| | - David C Schriemer
- From the ‡Department of Biochemistry and Molecular Biology, §Department of Chemistry,
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7
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Barber MF, Kronenberg Z, Yandell M, Elde NC. Antimicrobial Functions of Lactoferrin Promote Genetic Conflicts in Ancient Primates and Modern Humans. PLoS Genet 2016; 12:e1006063. [PMID: 27203426 PMCID: PMC4874600 DOI: 10.1371/journal.pgen.1006063] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 04/27/2016] [Indexed: 01/10/2023] Open
Abstract
Lactoferrin is a multifunctional mammalian immunity protein that limits microbial growth through sequestration of nutrient iron. Additionally, lactoferrin possesses cationic protein domains that directly bind and inhibit diverse microbes. The implications for these dual functions on lactoferrin evolution and genetic conflicts with microbes remain unclear. Here we show that lactoferrin has been subject to recurrent episodes of positive selection during primate divergence predominately at antimicrobial peptide surfaces consistent with long-term antagonism by bacteria. An abundant lactoferrin polymorphism in human populations and Neanderthals also exhibits signatures of positive selection across primates, linking ancient host-microbe conflicts to modern human genetic variation. Rapidly evolving sites in lactoferrin further correspond to molecular interfaces with opportunistic bacterial pathogens causing meningitis, pneumonia, and sepsis. Because microbes actively target lactoferrin to acquire iron, we propose that the emergence of antimicrobial activity provided a pivotal mechanism of adaptation sparking evolutionary conflicts via acquisition of new protein functions. Immunity genes can evolve rapidly in response to antagonism by microbial pathogens, but how the emergence of new protein functions impacts such evolutionary conflicts remains unclear. Here we have traced the evolutionary history of the lactoferrin gene in primates, which in addition to an ancient iron-binding function, acquired antimicrobial peptide activity in mammals. We show that, in contrast to the related gene transferrin, lactoferrin has rapidly evolved at protein domains that mediate iron-independent antimicrobial functions. We also pinpoint signatures of natural selection acting on lactoferrin in human populations, suggesting that lactoferrin genetic diversity has impacted the evolutionary success of both ancient primates and humans. Our work demonstrates how the emergence of new host immune protein functions can drastically alter evolutionary and molecular interactions with microbes.
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Affiliation(s)
- Matthew F Barber
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Zev Kronenberg
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Mark Yandell
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Nels C Elde
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
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8
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Curran DM, Adamiak PJ, Fegan JE, Qian C, Yu RH, Schryvers AB. Sequence and structural diversity of transferrin receptors in Gram-negative porcine pathogens. Vaccine 2015; 33:5700-5707. [PMID: 26263196 DOI: 10.1016/j.vaccine.2015.07.097] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 07/13/2015] [Accepted: 07/25/2015] [Indexed: 10/23/2022]
Abstract
Actinobacillus pleuropneumoniae, Actinobacillus suis, and Haemophilus parasuis are bacterial pathogens from the upper respiratory tract that are responsible for a substantial burden of porcine disease. Although reduction of disease has been accomplished by intensive management practices, immunization remains an important strategy for disease prevention, particularly when intensive management practices are not feasible or suitable. An attractive target for vaccine development is the surface receptor involved in acquiring iron from host transferrin, since it is common to all three pathogenic species and has been shown to be essential for survival and disease causation. It has also recently been demonstrated that an engineered antigen derived from the lipoprotein component of the receptor, transferrin-binding protein B (TbpB), was more effective at preventing infection by H. parasuis than a commercial vaccine product. This study was initiated to explore the genetic and immunogenic diversity of the transferrin receptor system from these species. Nucleic acid sequences were obtained from a geographically and temporally diverse collection of isolates, consisting of 41 A. pleuropneumoniae strains, 30 H. parasuis strains, and 2 A. suis strains. Phylogenetic analyses demonstrated that the receptor protein sequences cluster independently of species, suggesting that there is genetic exchange between these species such that receptor-based vaccines should logically target all three species. To evaluate the cross-reactive response of TbpB-derived antigens, pigs were immunized with the intact TbpB, the TbpB N-lobe and the TbpB C-lobe from A. pleuropneumoniae strain H49 and the resulting sera were tested against a representative panel of TbpBs; demonstrating that the C-lobe induces a broadly cross-reactive response. Overall our results indicate that there is a common reservoir for transferrin receptor antigenic variation amongst these pathogens. While this could present a challenge to future vaccine development, our results suggest a rationally designed TbpB-based vaccine may provide protection against all three pathogens.
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Affiliation(s)
- David M Curran
- Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
| | - Paul J Adamiak
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
| | - Jamie E Fegan
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
| | - Chenzhe Qian
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
| | - Rong-Hua Yu
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
| | - Anthony B Schryvers
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
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9
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Morgenthau A, Pogoutse A, Adamiak P, Moraes TF, Schryvers AB. Bacterial receptors for host transferrin and lactoferrin: molecular mechanisms and role in host–microbe interactions. Future Microbiol 2013; 8:1575-85. [DOI: 10.2217/fmb.13.125] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Iron homeostasis in the mammalian host limits the availability of iron to invading pathogens and is thought to restrict iron availability for microbes inhabiting mucosal surfaces. The presence of surface receptors for the host iron-binding glycoproteins transferrin (Tf) and lactoferrin (Lf) in globally important Gram-negative bacterial pathogens of humans and food production animals suggests that Tf and Lf are important sources of iron in the upper respiratory or genitourinary tracts, where they exclusively reside. Lf receptors have the additional function of protecting against host cationic antimicrobial peptides, suggesting that the bacteria expressing these receptors reside in a niche where exposure is likely. In this review we compare Tf and Lf receptors with respect to their structural and functional features, their role in colonization and infection, and their distribution among pathogenic and commensal bacteria.
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Affiliation(s)
- Ari Morgenthau
- Department of Microbiology, Immunology & Infectious Diseases, Health Sciences Centre, 3330 Hospital Drive Northwest Calgary, Alberta, T2N 4N1, Canada
| | - Anastassia Pogoutse
- Department of Biochemistry, Medical Sciences Building, King’s College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Paul Adamiak
- Department of Microbiology, Immunology & Infectious Diseases, Health Sciences Centre, 3330 Hospital Drive Northwest Calgary, Alberta, T2N 4N1, Canada
| | - Trevor F Moraes
- Department of Biochemistry, Medical Sciences Building, King’s College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Anthony B Schryvers
- Department of Biochemistry & Molecular Biology, Health Sciences Centre, 3330 Hospital Drive Northwest Calgary, Alberta, T2N 4N1, Canada
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10
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Steric and allosteric factors prevent simultaneous binding of transferrin-binding proteins A and B to transferrin. Biochem J 2012; 444:189-97. [DOI: 10.1042/bj20112133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The ability to acquire iron directly from host Tf (transferrin) is an adaptation common to important bacterial pathogens belonging to the Pasteurellaceae, Moraxellaceae and Neisseriaceae families. A surface receptor comprising an integral outer membrane protein, TbpA (Tf-binding protein A), and a surface-exposed lipoprotein, TbpB (Tf-binding protein B), mediates the iron acquisition process. TbpB is thought to extend from the cell surface for capture of Tf to initiate the process and deliver Tf to TbpA. TbpA functions as a gated channel for the passage of iron into the periplasm. In the present study we have mapped the effect of TbpA from Actinobacillus pleuropneumoniae on pTf (porcine Tf) using H/DX-MS (hydrogen/deuterium exchange coupled to MS) and compare it with a previously determined binding site for TbpB. The proposed TbpA footprint is adjacent to and potentially overlapping the TbpB-binding site, and induces a structural instability in the TbpB site. This suggests that simultaneous binding to pTf by both receptors would be hindered. We demonstrate that a recombinant TbpB lacking a portion of its anchor peptide is unable to form a stable ternary TbpA–pTf–TbpB complex. This truncated TbpB does not bind to a preformed Tf–TbpA complex, and TbpA removes pTf from a preformed Tf–TbpB complex. Thus the results of the present study support a model whereby TbpB ‘hands-off’ pTf to TbpA, which completes the iron removal and transport process.
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11
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Calmettes C, Alcantara J, Yu RH, Schryvers AB, Moraes TF. The structural basis of transferrin sequestration by transferrin-binding protein B. Nat Struct Mol Biol 2012; 19:358-60. [PMID: 22343719 PMCID: PMC3981719 DOI: 10.1038/nsmb.2251] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 01/19/2012] [Indexed: 12/14/2022]
Abstract
Neisseria meningitidis, the causative agent of bacterial meningitis, acquires the essential element iron from the host glycoprotein transferrin (Tf) during infection via a surface Tf receptor system composed of proteins TbpA and TbpB. Here in we present the crystal structures of TbpB from N. meningitidis, in its apo form and in complex with human Tf (hTf). The structure reveals how TbpB sequesters hTf and initiates iron release from hTf.
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Affiliation(s)
- Charles Calmettes
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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12
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Morgenthau A, Livingstone M, Adamiak P, Schryvers AB. The role of lactoferrin binding protein B in mediating protection against human lactoferricin. Biochem Cell Biol 2012; 90:417-23. [PMID: 22332888 DOI: 10.1139/o11-074] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Bacteria that inhabit the mucosal surfaces of the respiratory and genitourinary tracts of mammals encounter an iron-deficient environment because of iron sequestration by the host iron-binding proteins transferrin and lactoferrin. Lactoferrin is also present in high concentrations at sites of inflammation where the cationic, antimicrobial peptide lactoferricin is produced by proteolysis of lactoferrin. Several Gram-negative pathogens express a lactoferrin receptor that enables the bacteria to use lactoferrin as an iron source. The receptor is composed of an integral membrane protein, lactoferrin binding protein A (LbpA), and a membrane-bound lipoprotein, lactoferrin binding protein B (LbpB). LbpA is essential for growth with lactoferrin as the sole iron source, whereas the role of LbpB in iron acquisition is not yet known. In this study, we demonstrate that LbpB from 2 different species is capable of providing protection against the killing activity of a human lactoferrin-derived peptide. We investigated the prevalence of lactoferrin receptors in bacteria and examined their sequence diversity. We propose that the protection against the cationic antimicrobial human lactoferrin-derived peptide is associated with clusters of negatively charged amino acids in the C-terminal lobe of LbpB that is a common feature of this protein.
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Affiliation(s)
- Ari Morgenthau
- Department of Microbiology and Infectious Diseases, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
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13
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Arutyunova E, Brooks CL, Beddek A, Mak MW, Schryvers AB, Lemieux MJ. Crystal structure of the N-lobe of lactoferrin binding protein B from Moraxella bovis. Biochem Cell Biol 2012; 90:351-61. [PMID: 22332934 DOI: 10.1139/o11-078] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Lactoferrin (Lf) is a bi-lobed, iron-binding protein found on mucosal surfaces and at sites of inflammation. Gram-negative pathogens from the Neisseriaceae and Moraxellaceae families are capable of using Lf as a source of iron for growth through a process mediated by a bacterial surface receptor that directly binds host Lf. This receptor consists of an integral outer membrane protein, lactoferrin binding protein A (LbpA), and a surface lipoprotein, lactoferrin binding protein B (LbpB). The N-lobe of the homologous transferrin binding protein B, TbpB, has been shown to facilitate transferrin binding in the process of iron acquisition. Currently there is little known about the role of LbpB in iron acquisition or how Lf interacts with the bacterial receptor proteins. No structural information on any LbpB or domain is available. In this study, we express and purify from Escherichia coli the full-length LbpB and the N-lobe of LbpB from the bovine pathogen Moraxella bovis for crystallization trials. We demonstrate that M. bovis LbpB binds to bovine but not human Lf. We also report the crystal structure of the N-terminal lobe of LbpB from M. bovis and compare it with the published structures of TbpB to speculate on the process of Lf mediated iron acquisition.
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Affiliation(s)
- Elena Arutyunova
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
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14
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Noinaj N, Easley NC, Oke M, Mizuno N, Gumbart J, Boura E, Steere AN, Zak O, Aisen P, Tajkhorshid E, Evans RW, Gorringe AR, Mason AB, Steven AC, Buchanan SK. Structural basis for iron piracy by pathogenic Neisseria. Nature 2012; 483:53-8. [PMID: 22327295 PMCID: PMC3292680 DOI: 10.1038/nature10823] [Citation(s) in RCA: 201] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 01/09/2012] [Indexed: 11/20/2022]
Abstract
Neisseria are obligate human pathogens causing bacterial meningitis, septicaemia and gonorrhoea. Neisseria require iron for survival and can extract it directly from human transferrin for transport across the outer membrane. The transport system consists of TbpA, an integral outer membrane protein, and TbpB, a co-receptor attached to the cell surface; both proteins are potentially important vaccine and therapeutic targets. Two key questions driving Neisseria research are how human transferrin is specifically targeted, and how the bacteria liberate iron from transferrin at neutral pH. To address these questions, we solved crystal structures of the TbpA-transferrin complex and of the corresponding co-receptor TbpB. We characterized the TbpB-transferrin complex by small-angle X-ray scattering and the TbpA-TbpB-transferrin complex by electron microscopy. Our studies provide a rational basis for the specificity of TbpA for human transferrin, show how TbpA promotes iron release from transferrin, and elucidate how TbpB facilitates this process.
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Affiliation(s)
- Nicholas Noinaj
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, US National Institutes of Health, Bethesda, Maryland 20892, USA
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15
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Percy AJ, Rey M, Burns KM, Schriemer DC. Probing protein interactions with hydrogen/deuterium exchange and mass spectrometry-a review. Anal Chim Acta 2012; 721:7-21. [PMID: 22405295 DOI: 10.1016/j.aca.2012.01.037] [Citation(s) in RCA: 129] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 01/13/2012] [Accepted: 01/17/2012] [Indexed: 11/17/2022]
Abstract
Assessing the functional outcome of protein interactions in structural terms is a goal of structural biology, however most techniques have a limited capacity for making structure-function determinations with both high resolution and high throughput. Mass spectrometry can be applied as a reader of protein chemistries in order to fill this void, and enable methodologies whereby protein structure-function determinations may be made on a proteome-wide level. Protein hydrogen/deuterium exchange (H/DX) offers a chemical labeling strategy suitable for tracking changes in "dynamic topography" and thus represents a powerful means of monitoring protein structure-function relationships. This review presents the exchange method in the context of interaction analysis. Applications involving interface detection, quantitation of binding, and conformational responses to ligation are discussed, and commentary on recent analytical developments is provided.
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Affiliation(s)
- Andrew J Percy
- Department of Chemistry, University of Calgary, Alberta, Canada
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16
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Yang X, Yu RH, Calmettes C, Moraes TF, Schryvers AB. Anchor peptide of transferrin-binding protein B is required for interaction with transferrin-binding protein A. J Biol Chem 2011; 286:45165-73. [PMID: 22069313 DOI: 10.1074/jbc.m110.214171] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Gram-negative bacterial pathogens belonging to the Pasteurellaceae, Moraxellaceae, and Neisseriaceae families rely on an iron acquisition system that acquires iron directly from host transferrin (Tf). The process is mediated by a surface receptor composed of transferrin-binding proteins A and B (TbpA and TbpB). TbpA is an integral outer membrane protein that functions as a gated channel for the passage of iron into the periplasm. TbpB is a surface-exposed lipoprotein that facilitates the iron uptake process. In this study, we demonstrate that the region encompassing amino acids 7-40 of Actinobacillus pleuropneumoniae TbpB is required for forming a complex with TbpA and that the formation of the complex requires the presence of porcine Tf. These results are consistent with a model in which TbpB is responsible for the initial capture of iron-loaded Tf and subsequently interacts with TbpA through the anchor peptide. We propose that TonB binding to TbpA initiates the formation of the TbpB-TbpA complex and transfer of Tf to TbpA.
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Affiliation(s)
- Xue Yang
- Department of Microbiology and Infectious Diseases, University of Calgary, Calgary T2N 4N1 Alberta, Canada
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