1
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Lenza MP, Oyenarte I, Diercks T, Quintana JI, Gimeno A, Coelho H, Diniz A, Peccati F, Delgado S, Bosch A, Valle M, Millet O, Abrescia NGA, Palazón A, Marcelo F, Jiménez‐Osés G, Jiménez‐Barbero J, Ardá A, Ereño‐Orbea J. Structural Characterization of N-Linked Glycans in the Receptor Binding Domain of the SARS-CoV-2 Spike Protein and their Interactions with Human Lectins. Angew Chem Int Ed Engl 2020; 59:23763-23771. [PMID: 32915505 PMCID: PMC7894318 DOI: 10.1002/anie.202011015] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/08/2020] [Indexed: 01/17/2023]
Abstract
The glycan structures of the receptor binding domain of the SARS-CoV2 spike glycoprotein expressed in human HEK293F cells have been studied by using NMR. The different possible interacting epitopes have been deeply analysed and characterized, providing evidence of the presence of glycan structures not found in previous MS-based analyses. The interaction of the RBD 13 C-labelled glycans with different human lectins, which are expressed in different organs and tissues that may be affected during the infection process, has also been evaluated by NMR. In particular, 15 N-labelled galectins (galectins-3, -7 and -8 N-terminal), Siglecs (Siglec-8, Siglec-10), and C-type lectins (DC-SIGN, MGL) have been employed. Complementary experiments from the glycoprotein perspective or from the lectin's point of view have permitted to disentangle the specific interacting epitopes in each case. Based on these findings, 3D models of the interacting complexes have been proposed.
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Affiliation(s)
- Maria Pia Lenza
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
| | - Iker Oyenarte
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
| | - Tammo Diercks
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
| | - Jon Imanol Quintana
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
| | - Ana Gimeno
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
| | - Helena Coelho
- UCIBIOREQUIMTEDepartamento de QuímicaFaculdade de Ciências e TecnologiaUniversidade NOVA de Lisboa2829-516CaparicaPortugal
| | - Ana Diniz
- UCIBIOREQUIMTEDepartamento de QuímicaFaculdade de Ciências e TecnologiaUniversidade NOVA de Lisboa2829-516CaparicaPortugal
| | - Francesca Peccati
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
| | - Sandra Delgado
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
| | - Alexandre Bosch
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
| | - Mikel Valle
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
| | - Oscar Millet
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
| | - Nicola G. A. Abrescia
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
- Ikerbasque, Basque Foundation for Science48013BilbaoSpain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd)Instituto de Salud Carlos IIIMadridSpain
| | - Asís Palazón
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
- Ikerbasque, Basque Foundation for Science48013BilbaoSpain
| | - Filipa Marcelo
- UCIBIOREQUIMTEDepartamento de QuímicaFaculdade de Ciências e TecnologiaUniversidade NOVA de Lisboa2829-516CaparicaPortugal
| | - Gonzalo Jiménez‐Osés
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
| | - Jesús Jiménez‐Barbero
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
- Ikerbasque, Basque Foundation for Science48013BilbaoSpain
- Department of Organic Chemistry IIUniversity of the Basque CountryUPV/EHU48940LeioaSpain
| | - Ana Ardá
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
| | - June Ereño‐Orbea
- CIC bioGUNEBasque Research and Technology AllianceBRTABizkaia Technology Park48162DerioSpain
- Ikerbasque, Basque Foundation for Science48013BilbaoSpain
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2
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Lenza MP, Oyenarte I, Diercks T, Quintana JI, Gimeno A, Coelho H, Diniz A, Peccati F, Delgado S, Bosch A, Valle M, Millet O, Abrescia NGA, Palazón A, Marcelo F, Jiménez‐Osés G, Jiménez‐Barbero J, Ardá A, Ereño‐Orbea J. Structural Characterization of N‐Linked Glycans in the Receptor Binding Domain of the SARS‐CoV‐2 Spike Protein and their Interactions with Human Lectins. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202011015] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Maria Pia Lenza
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
| | - Iker Oyenarte
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
| | - Tammo Diercks
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
| | - Jon Imanol Quintana
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
| | - Ana Gimeno
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
| | - Helena Coelho
- UCIBIO REQUIMTE Departamento de Química Faculdade de Ciências e Tecnologia Universidade NOVA de Lisboa 2829-516 Caparica Portugal
| | - Ana Diniz
- UCIBIO REQUIMTE Departamento de Química Faculdade de Ciências e Tecnologia Universidade NOVA de Lisboa 2829-516 Caparica Portugal
| | - Francesca Peccati
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
| | - Sandra Delgado
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
| | - Alexandre Bosch
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
| | - Mikel Valle
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
| | - Oscar Millet
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
| | - Nicola G. A. Abrescia
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
- Ikerbasque, Basque Foundation for Science 48013 Bilbao Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) Instituto de Salud Carlos III Madrid Spain
| | - Asís Palazón
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
- Ikerbasque, Basque Foundation for Science 48013 Bilbao Spain
| | - Filipa Marcelo
- UCIBIO REQUIMTE Departamento de Química Faculdade de Ciências e Tecnologia Universidade NOVA de Lisboa 2829-516 Caparica Portugal
| | - Gonzalo Jiménez‐Osés
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
| | - Jesús Jiménez‐Barbero
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
- Ikerbasque, Basque Foundation for Science 48013 Bilbao Spain
- Department of Organic Chemistry II University of the Basque Country UPV/EHU 48940 Leioa Spain
| | - Ana Ardá
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
| | - June Ereño‐Orbea
- CIC bioGUNE Basque Research and Technology Alliance BRTA Bizkaia Technology Park 48162 Derio Spain
- Ikerbasque, Basque Foundation for Science 48013 Bilbao Spain
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3
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Unione L, Lenza M, Ardá A, Urquiza P, Laín A, Falcón-Pérez JM, Jiménez-Barbero J, Millet O. Glycoprofile Analysis of an Intact Glycoprotein As Inferred by NMR Spectroscopy. ACS CENTRAL SCIENCE 2019; 5:1554-1561. [PMID: 31572782 PMCID: PMC6764210 DOI: 10.1021/acscentsci.9b00540] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Indexed: 05/10/2023]
Abstract
Protein N-glycosylation stands out for its intrinsic and functionally related heterogeneity. Despite its biomedical interest, Glycoprofile analysis still remains a major scientific challenge. Here, we present an NMR-based strategy to delineate the N-glycan composition in intact glycoproteins and under physiological conditions. The employed methodology allowed dissecting the glycan pattern of the IgE high-affinity receptor (FcεRIα) expressed in human HEK 293 cells, identifying the presence and relative abundance of specific glycan epitopes. Chemical shifts and differences in the signal line-broadening between the native and the unfolded states were integrated to build a structural model of FcεRIα that was able to identify intramolecular interactions between high-mannose N-glycans and the protein surface. In turn, complex type N-glycans reflect a large solvent accessibility, suggesting a functional role as interaction sites for receptors. The interaction between intact FcεRIα and the lectin hGal3, also studied here, confirms this hypothesis and opens new avenues for the detection of specific N-glycan epitopes and for the studies of glycoprotein-receptor interactions mediated by N-glycans.
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Affiliation(s)
- Luca Unione
- CIC
bioGUNE, Bizkaia Technology Park, Bld 800, 48170 Derio, Spain
- E-mail:
| | - Maria
Pia Lenza
- CIC
bioGUNE, Bizkaia Technology Park, Bld 800, 48170 Derio, Spain
| | - Ana Ardá
- CIC
bioGUNE, Bizkaia Technology Park, Bld 800, 48170 Derio, Spain
| | - Pedro Urquiza
- CIC
bioGUNE, Bizkaia Technology Park, Bld 800, 48170 Derio, Spain
| | - Ana Laín
- CIC
bioGUNE, Bizkaia Technology Park, Bld 800, 48170 Derio, Spain
| | - Juan Manuel Falcón-Pérez
- CIC
bioGUNE, Bizkaia Technology Park, Bld 800, 48170 Derio, Spain
- Basque
Foundation for Science IKERBASQUE, 48009 Bilbao, Spain
| | - Jesús Jiménez-Barbero
- CIC
bioGUNE, Bizkaia Technology Park, Bld 800, 48170 Derio, Spain
- Basque
Foundation for Science IKERBASQUE, 48009 Bilbao, Spain
- Dept.
Organic Chemistry II, Faculty of Science and Technology, University of the Basque Country, 48940 Leioa, Spain
- E-mail:
| | - Oscar Millet
- CIC
bioGUNE, Bizkaia Technology Park, Bld 800, 48170 Derio, Spain
- E-mail:
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4
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Asselstine V, Miglior F, Suárez-Vega A, Fonseca PAS, Mallard B, Karrow N, Islas-Trejo A, Medrano JF, Cánovas A. Genetic mechanisms regulating the host response during mastitis. J Dairy Sci 2019; 102:9043-9059. [PMID: 31421890 DOI: 10.3168/jds.2019-16504] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 06/05/2019] [Indexed: 12/21/2022]
Abstract
Mastitis is a very costly and common disease in the dairy industry. The study of the transcriptome from healthy and mastitic milk somatic cell samples using RNA-Sequencing technology can provide measurements of transcript levels associated with the immune response to the infection. The objective of this study was to characterize the Holstein milk somatic cell transcriptome from 6 cows to determine host response to intramammary infections. RNA-Sequencing was performed on 2 samples from each cow from 2 separate quarters, one classified as healthy (n = 6) and one as mastitic (n = 6). In total, 449 genes were differentially expressed between the healthy and mastitic quarters (false discovery rate <0.05, fold change >±2). Among the differentially expressed genes, the most expressed genes based on reads per kilobase per million mapped reads (RPKM) in the healthy group were associated with milk components (CSN2 and CSN3), and in the mastitic group they were associated with immunity (B2M and CD74). In silico functional analysis was performed using the list of 449 differentially expressed genes, which identified 36 significantly enriched metabolic pathways (false discovery rate <0.01), some of which were associated with the immune system, such as cytokine-cytokine interaction and cell adhesion molecules. Seven functional candidate genes were selected, based on the criteria of being highly differentially expressed between healthy and mastitic groups and significantly enriched in metabolic pathways that are relevant to the inflammatory process (GLYCAM1, B2M, CD74, BoLA-DRA, FCER1G, SDS, and NFKBIA). Last, we identified the differentially expressed genes that are located in quantitative trait locus regions previously known to be associated with mastitis, specifically clinical mastitis, somatic cell count, and somatic cell score. It was concluded that multiple genes within quantitative trait locus regions could potentially affect host response to mastitis-causing agents, making some cows more susceptible to intramammary infections. The identification of potential candidate genes with functional, statistical, biological, and positional relevance associated with host defense to infection will contribute to a better understanding of the underlying genetic architecture associated with mastitis. This in turn will improve the sustainability of agricultural practices by facilitating the selection of cows with improved host defense leading to increased resistance to mastitis.
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Affiliation(s)
- V Asselstine
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
| | - F Miglior
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
| | - A Suárez-Vega
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
| | - P A S Fonseca
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
| | - B Mallard
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
| | - N Karrow
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
| | - A Islas-Trejo
- Department of Animal Science, University of California-Davis, Davis 95616
| | - J F Medrano
- Department of Animal Science, University of California-Davis, Davis 95616
| | - A Cánovas
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada, N1G 2W1.
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5
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Sutton BJ, Davies AM. Structure and dynamics of IgE-receptor interactions: FcεRI and CD23/FcεRII. Immunol Rev 2015; 268:222-35. [DOI: 10.1111/imr.12340] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Brian J. Sutton
- Randall Division of Cell and Molecular Biophysics; King's College London; London UK
- Medical Research Council & Asthma UK Centre in Allergic Mechanisms of Asthma; London UK
| | - Anna M. Davies
- Randall Division of Cell and Molecular Biophysics; King's College London; London UK
- Medical Research Council & Asthma UK Centre in Allergic Mechanisms of Asthma; London UK
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6
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Caaveiro JMM, Kiyoshi M, Tsumoto K. Structural analysis of Fc/FcγR complexes: a blueprint for antibody design. Immunol Rev 2015; 268:201-21. [DOI: 10.1111/imr.12365] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Jose M. M. Caaveiro
- Department of Bioengineering; School of Engineering; The University of Tokyo; Tokyo Japan
| | - Masato Kiyoshi
- Department of Bioengineering; School of Engineering; The University of Tokyo; Tokyo Japan
- Division of Biological Chemistry and Biologicals; National Institute of Health Sciences; Tokyo Japan
| | - Kouhei Tsumoto
- Department of Bioengineering; School of Engineering; The University of Tokyo; Tokyo Japan
- Institute of Medical Science; The University of Tokyo; Tokyo Japan
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7
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Pushparaj PN, Rasool M, Naseer MI, Damiati LA, Kothandaraman N, Gauthaman K, Bhalas S, Manikandan J. Disease associated cellular machinery in anaphylaxis - And the de novo paradigm shift. Bioinformation 2015; 11:43-6. [PMID: 25780280 PMCID: PMC4349939 DOI: 10.6026/97320630011043] [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: 12/25/2014] [Accepted: 01/13/2015] [Indexed: 11/23/2022] Open
Abstract
Anaphylaxis is a sudden immune reaction against an allergen that can potentially lead to Anaphylactic Shock (AS). This immune
reaction is characterized by an increase in Immunoglobulin-E (IgE) type of antibodies that bind with FcεRI receptors on mast cells
to release inflammatory mediators. Various intracellular signaling molecules downstream of IgE/ FcεRI axis play a potential role in
cytokine, chemokine and eicosanoid secretion as well as degranulation of immune cells causing vasodilation, vascular
permeability, and reduction of intravascular volume leading to cardiovascular collapse. Here, we discuss the cellular machinery of
anaphylaxis and the de novo paradigm shift in the cellular aspects of AS.
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Affiliation(s)
- Peter Natesan Pushparaj
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Kingdom of Saudi Arabia
| | - Mahmood Rasool
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Kingdom of Saudi Arabia
| | - Muhammad Imran Naseer
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Kingdom of Saudi Arabia
| | - Laila Abdullah Damiati
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Kingdom of Saudi Arabia
| | - Narasimhan Kothandaraman
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Kingdom of Saudi Arabia
| | - Kalamegam Gauthaman
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Kingdom of Saudi Arabia
| | - Sami Bhalas
- Department of Internal Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Kingdom of Saudi Arabia
| | - Jayapal Manikandan
- Faculty of Life and Physical Sciences, The University of Western Australia (M011), 35 Stirling Highway, Crawley, WA 6009, Australia
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8
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Recombinant canine IgE Fc and an IgE Fc-TRAIL fusion protein bind to neoplastic canine mast cells. Vet Immunol Immunopathol 2014; 159:29-40. [DOI: 10.1016/j.vetimm.2014.02.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 02/03/2014] [Accepted: 02/25/2014] [Indexed: 11/22/2022]
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9
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Development of small molecules to target the IgE:FcεRI protein-protein interaction in allergies. Future Med Chem 2014; 5:1423-35. [PMID: 23919552 DOI: 10.4155/fmc.13.112] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The protein-protein interaction (PPI) between IgE and its high-affinity receptor (FcεRI) is a key component of the allergic response. Inhibiting the IgE:FcεRI PPI is an attractive strategy for therapeutic intervention and the development of allergy treatments. This PPI has been validated as a viable target by the monoclonal anti-IgE antibody omalizumab (Xolair(®)), which has demonstrated clinical efficacy when prescribed to treat moderate-to-severe asthma and hay fever, but small molecules would be a more convenient form of treatment. Cyclic peptides, small proteins and a natural product have all been developed to target the IgE:FcεRI PPI, and these will be discussed in this review. Targeting the IgE:FcεRI complex with small molecules presents various challenges, some of which are inherent in all PPI targets but some of which are unique to this system, which presents great opportunities for the development of new therapeutics for the treatment of allergies.
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10
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Potaczek DP, Kabesch M. Current concepts of IgE regulation and impact of genetic determinants. Clin Exp Allergy 2013; 42:852-71. [PMID: 22909159 DOI: 10.1111/j.1365-2222.2011.03953.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Immunoglobulin E (IgE) mediated immune responses seem to be directed against parasites and neoplasms, but are best known for their involvement in allergies. The IgE network is tightly controlled at different levels as outlined in this review. Genetic determinants were suspected to influence IgE regulation and IgE levels considerably for many years. Linkage and candidate gene studies suggested a number of loci and genes to correlate with total serum IgE levels, and recently genome-wide association studies (GWAS) provided the power to identify genetic determinants for total serum IgE levels: 1q23 (FCER1A), 5q31 (RAD50, IL13, IL4), 12q13 (STAT6), 6p21.3 (HLA-DRB1) and 16p12 (IL4R, IL21R). In this review, we analyse the potential role of these GWAS hits in the IgE network and suggest mechanisms of how genes and genetic variants in these loci may influence IgE regulation.
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Affiliation(s)
- D P Potaczek
- Department of Pediatric Pneumology, Allergy and Neonatology, Hannover Medical School, Hannover, Germany
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11
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Kim B, Tarchevskaya SS, Eggel A, Vogel M, Jardetzky TS. A time-resolved fluorescence resonance energy transfer assay suitable for high-throughput screening for inhibitors of immunoglobulin E-receptor interactions. Anal Biochem 2012; 431:84-9. [PMID: 22995065 DOI: 10.1016/j.ab.2012.09.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 09/09/2012] [Indexed: 11/19/2022]
Abstract
The interaction of immunoglobulin E (IgE) antibodies with the high-affinity receptor, FcεRI, plays a central role in initiating most allergic reactions. The IgE-receptor interaction has been targeted for treatment of allergic diseases, and many high-affinity macromolecular inhibitors have been identified. Small molecule inhibitors would offer significant advantages over current anti-IgE treatment, but no candidate compounds have been identified and fully validated. Here, we report the development of a time-resolved fluorescence resonance energy transfer (TR-FRET) assay for monitoring the IgE-receptor interaction. The TR-FRET assay measures an increase in fluorescence intensity as a donor lanthanide fluorophore is recruited into complexes of site-specific Alexa Fluor 488-labeled IgE-Fc and His-tagged FcεRIα proteins. The assay can readily monitor classic competitive inhibitors that bind either IgE-Fc or FcεRIα in equilibrium competition binding experiments. Furthermore, the TR-FRET assay can also be used to follow the kinetics of IgE-Fc-FcεRIα dissociation and identify inhibitory ligands that accelerate the dissociation of preformed complexes, as demonstrated for an engineered DARPin (designed ankyrin repeat protein) inhibitor. The TR-FRET assay is suitable for high-throughput screening (HTS), as shown by performing a pilot screen of the National Institutes of Health (NIH) Clinical Collection Library in a 384-well plate format.
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Affiliation(s)
- Beomkyu Kim
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
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12
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Wurzburg BA, Kim B, Tarchevskaya SS, Eggel A, Vogel M, Jardetzky TS. An engineered disulfide bond reversibly traps the IgE-Fc3-4 in a closed, nonreceptor binding conformation. J Biol Chem 2012; 287:36251-7. [PMID: 22948141 DOI: 10.1074/jbc.m112.407502] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
IgE antibodies interact with the high affinity IgE Fc receptor, FcεRI, and activate inflammatory pathways associated with the allergic response. The IgE-Fc region, comprising the C-terminal domains of the IgE heavy chain, binds FcεRI and can adopt different conformations ranging from a closed form incompatible with receptor binding to an open, receptor-bound state. A number of intermediate states are also observed in different IgE-Fc crystal forms. To further explore this apparent IgE-Fc conformational flexibility and to potentially trap a closed, inactive state, we generated a series of disulfide bond mutants. Here we describe the structure and biochemical properties of an IgE-Fc mutant that is trapped in the closed, non-receptor binding state via an engineered disulfide at residue 335 (Cys-335). Reduction of the disulfide at Cys-335 restores the ability of IgE-Fc to bind to its high affinity receptor, FcεRIα. The structure of the Cys-335 mutant shows that its conformation is within the range of previously observed, closed form IgE-Fc structures and that it retains the hydrophobic pocket found in the hinge region of the closed conformation. Locking the IgE-Fc into the closed state with the Cys-335 mutation does not affect binding of two other IgE-Fc ligands, omalizumab and DARPin E2_79, demonstrating selective blocking of the high affinity receptor binding.
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Affiliation(s)
- Beth A Wurzburg
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305, USA
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13
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Manikandan J, Kothandaraman N, Hande MP, Pushparaj PN. Deciphering the structure and function of FcεRI/mast cell axis in the regulation of allergy and anaphylaxis: a functional genomics paradigm. Cell Mol Life Sci 2012; 69:1917-29. [PMID: 22146792 PMCID: PMC11114762 DOI: 10.1007/s00018-011-0886-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Revised: 10/27/2011] [Accepted: 11/07/2011] [Indexed: 10/14/2022]
Abstract
Allergy and anaphylaxis are inflammatory disorders caused by immune reactions mainly induced by immunoglobulin-E that signal through the high-affinity FcεRI receptor to release the inflammatory mediators from innate immune cells. The FcεRI/mast cell axis is potently involved in triggering various intracellular signaling molecules to induce calcium release from the internal stores, induction of transcription factors such as NF-kB, secretion of various cytokines as well as lipid mediators, and degranulation, resulting in the induction of allergy and anaphylaxis. In this review, we discuss various cellular and molecular mechanisms triggered through FcεRI/mast cell axis in allergy and anaphylaxis with a special emphasis on the functional genomics paradigm.
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Affiliation(s)
- Jayapal Manikandan
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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14
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Xi J, Zhang GP, Qiao SL, Guo JQ, Wang XN, Yang YY, Zhang LN, Miao XW, Zhao D, Zhi YB, Cai SJ, Luo J, Deng RG. Increased survival and reduced renal injury in MRL/lpr mice treated with a human Fcγ receptor II (CD32) peptide. Immunology 2012; 136:46-53. [PMID: 22236212 DOI: 10.1111/j.1365-2567.2012.03553.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Systemic lupus erythematosus (SLE) is a multisystem chronic inflammatory disease affecting many organs. The deposition in kidney tissue of immune complexes and their interaction with macrophages is thought to trigger the inflammatory response leading to glomerulonephritis. It has been demonstrated that inhibition of this interaction in murine models can alleviate the disease. Six synthetic peptides were derived from the membrane-proximal extracellular domain (EC2) of human Fcγ receptor II (huFcγRII). Of these, one peptide, huRII6, was shown to be a potent competitive inhibitor of IgG binding to recombinant FcγRII in vitro. To examine the possible therapeutic impact of huRII6 in vivo, this peptide, or a control, was given by subcutaneous injection to female MRL/lpr mice from weeks 7 to 36, resulting in an enhanced survival rate compared with control-treated animals and a reduction of proteinuria. Histopathological examination of the kidneys showed a reduction in deposition of immune complexes and preservation of structure. Such a functional peptide should prove useful for examining the role of IgG-FcγR interactions in experimental models of disease and may provide for the development of FcR-targeting drugs to treat autoimmune disorders.
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Affiliation(s)
- Jun Xi
- School of Food Science and Technology, Henan University of Technology, Zhengzhou, China.
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15
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Offermann DA, McKendrick JE, Sejberg JJP, Mo B, Holdom MD, Helm BA, Leatherbarrow RJ, Beavil AJ, Sutton BJ, Spivey AC. Synthesis and incorporation into cyclic peptides of tolan amino acids and their hydrogenated congeners: construction of an array of A-B-loop mimetics of the Cε3 domain of human IgE. J Org Chem 2012; 77:3197-214. [PMID: 22397517 DOI: 10.1021/jo202604q] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The disruption of the human immunolobulin E-high affinity receptor I (IgE-FcεRI) protein-protein interaction (PPI) is a validated strategy for the development of anti asthma therapeutics. Here, we describe the synthesis of an array of conformationally constrained cyclic peptides based on an epitope of the A-B loop within the Cε3 domain of IgE. The peptides contain various tolan (i.e., 1,2-biarylethyne) amino acids and their fully and partially hydrogenated congeners as conformational constraints. Modest antagonist activity (IC(50) ∼660 μM) is displayed by the peptide containing a 2,2'-tolan, which is the one predicted by molecular modeling to best mimic the conformation of the native A-B loop epitope in IgE.
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Affiliation(s)
- Daniel A Offermann
- Department of Chemistry, South Kensington Campus, Imperial College, London SW7 2AZ, UK
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16
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Holdom MD, Davies AM, Nettleship JE, Bagby SC, Dhaliwal B, Girardi E, Hunt J, Gould HJ, Beavil AJ, McDonnell JM, Owens RJ, Sutton BJ. Conformational changes in IgE contribute to its uniquely slow dissociation rate from receptor FcɛRI. Nat Struct Mol Biol 2011; 18:571-6. [PMID: 21516097 PMCID: PMC3357048 DOI: 10.1038/nsmb.2044] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 02/11/2011] [Indexed: 11/09/2022]
Abstract
Among antibody classes, IgE has a uniquely slow dissociation rate from, and high affinity for, its cell surface receptor FcɛRI. We show the structural basis for these key determinants of the ability of IgE to mediate allergic hypersensitivity through the 3.4-Å-resolution crystal structure of human IgE-Fc (consisting of the Cɛ2, Cɛ3 and Cɛ4 domains) bound to the extracellular domains of the FcɛRI α chain. Comparison with the structure of free IgE-Fc (reported here at a resolution of 1.9 Å) shows that the antibody, which has a compact, bent structure before receptor engagement, becomes even more acutely bent in the complex. Thermodynamic analysis indicates that the interaction is entropically driven, which explains how the noncontacting Cɛ2 domains, in place of the flexible hinge region of IgG antibodies, contribute together with the conformational changes to the unique binding properties of IgE.
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Affiliation(s)
- Mary D Holdom
- King's College London, Randall Division of Cell and Molecular Biophysics, London, UK
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17
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Sandomenico A, Monti SM, Palumbo R, Ruvo M. A new FcεRI receptor-mimetic peptide (PepE) that blocks IgE binding to its high affinity receptor and prevents mediator release from RBL 2H3 cells. J Pept Sci 2011; 17:604-9. [DOI: 10.1002/psc.1368] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 01/26/2011] [Accepted: 01/31/2011] [Indexed: 11/08/2022]
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18
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Xi J, Zhang LN, Hu GP, Wang L, Qiao SL, Guo JQ, Lu QY, Zhang GP, Yang YY. Identification of a linear epitope for Fc-binding in the mouse FcγRIII. Peptides 2010; 31:1684-8. [PMID: 20566342 DOI: 10.1016/j.peptides.2010.05.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Revised: 05/31/2010] [Accepted: 05/31/2010] [Indexed: 11/26/2022]
Abstract
Fc receptors are transmembrane proteins, found on the surfaces of immune cells, that aid in the removal of foreign pathogens by binding to antibody-coated targets via the Fc regions of the antibodies. To identify sites on mouse FcgammaRIII (moFcgammaRIII) alpha-chain that bind to the Fc region, peptides derived from the proximal extracellular domain (EC2) of moFcgammaRIII alpha-chain corresponding to the homologous region of human FcgammaRIIIB alpha-chain were synthesized. Binding of mouse IgG to the different peptides was tested by Dot-blot assay. The effective peptide (119)SFFHNEKSVRYH(130) located in the putative C-C' loop of the EC2 domain was found to bind mouse IgG specifically with an affinity of approximately 5.58 x 10(-5) M and inhibit the binding of mouse IgG to the receptor. Such a functional peptide should be very useful for further understanding the IgG-FcgammaR interaction and development of FcR-targeting drugs.
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Affiliation(s)
- Jun Xi
- School of Food Science and Technology, Henan University of Technology, Zhengzhou 450052, China
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19
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Ross A, Soares DC, Covelli D, Pannecouque C, Budd L, Collins A, Robertson N, Parsons S, De Clercq E, Kennepohl P, Sadler PJ. Oxovanadium(IV) cyclam and bicyclam complexes: potential CXCR4 receptor antagonists. Inorg Chem 2010; 49:1122-32. [PMID: 20039648 DOI: 10.1021/ic9020614] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Metal complexation can have a major influence on the antiviral and coreceptor binding properties of cyclam and bicyclam macrocycles. We report the synthesis of the vanadyl cyclam complexes [V((IV))O(cyclam)SO(4)] (1) and [V((IV))O(cyclam)Cl]Cl (2) and the analogous xylylbicyclam sulfato (3) and chlorido (4) complexes. The X-ray crystal structures of 1.1.33CH(3)OH and 2.CH(3)OH.1.5H(2)O show short V=O bonds (1.6093(19) and 1.599(3) A, respectively) with monodentate sulfate H-bonded to ring NH groups for 1, but a long V-Cl bond (2.650(12) A) for 2. The solid-state structures of 3 and 4 were compared to those of 1 and 2 using vanadium K-edge extended X-ray absorption fine structure (EXAFS) data. These suggested that complex 4 was oligomeric and contained bridging chlorido ligands. Electron paramagnetic resonance (EPR) studies suggested that the SO(4)(2-) (from 1) and Cl(-) (from 2) ligands are readily substituted by water in solution, whereas these remain partially bound for the V(IV) xylylbicyclam complexes 3 and 4. The vanadyl xylylbicyclam complexes were highly active against HIV-1 (III(B)) and HIV-2 (ROD) strains with IC(50) values in the range 1-5 microM for 3 and 0.1-0.3 microM for 4; in contrast the vanadyl cyclam complexes 1 and 2 were inactive. The factors that contribute to the activity of these complexes are discussed. Studies of vanadyl cyclam docked into a model of the human CXCR4 coreceptor revealed that the coordination of vanadium to the carboxylate of Asp171 may be accompanied by H-bonding to the macrocycle and an attractive V=O...H interaction involving the backbone Trp195 alpha-carbon proton of CXCR4. In addition, hydrophobic interactions with Trp195 are present. Both ring configuration and the xylyl linker may play roles in determining the higher activity of the bicyclam complexes.
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Affiliation(s)
- Allison Ross
- School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, UK
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20
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IgE-binding properties and selectivity of peptide mimics of the FcvarepsilonRI binding site. Mol Immunol 2009; 46:3300-9. [PMID: 19699527 DOI: 10.1016/j.molimm.2009.07.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Accepted: 07/26/2009] [Indexed: 11/21/2022]
Abstract
FcvarepsilonRIalpha found on the surface of mast cells and basophiles mediates allergic diseases, anaphylaxis and asthma through binding of IgE. Disrupting this interaction with anti-IgE mAbs has proven an efficient approach to control these diseases. The crystallographic structure of the complex formed between the IgE-Fc and FcvarepsilonRIalpha extracellular domain has shown that recognition is mediated by residues in the second Ig-like domain of the receptor (D2) and in the loop connecting the D1 and D2 domains. In an attempt to obtain specific IgE antagonists, we have designed and prepared a polypeptide named IgE-Trap that partially reproduces the IgE receptor-binding sites and binds with micromolar affinity to soluble IgE. The polypeptide contains loops C'-E [residues 129-134] and F-G [residues 151-161] from the D2 domain joined by a linker, and loop B-C [residues 110-113]. Peptide binding to IgE has been assessed by SPR analyses and the data fit with a biphasic model of interaction, in agreement with the two-site mechanism reported for the native receptor. The polypeptide binds to immobilized IgE in a dose-dependent manner with a K(D) estimated to be around 6muM, while it does not recognize IgG nor IgA. Polypeptide sub-domains involved in IgE binding have also been defined, showing that loop C'-E connected to loop B-C, but also the isolated loop B-C alone suffice to bind immunoglobulins E with high selectively though with reduced affinity compared to IgE-Trap. ELISA and cytometric assays on RBL2H3 cells demonstrate that the interacting peptides are able to displace the binding of IgE to receptor, confirming affinity and specificity of these ligands and suggesting a potential application as modulators of disorders associated with inappropriate IgE production.
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21
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Hunt J, Bracher MG, Shi J, Fleury S, Dombrowicz D, Gould HJ, Sutton BJ, Beavil AJ. Attenuation of IgE affinity for FcepsilonRI radically reduces the allergic response in vitro and in vivo. J Biol Chem 2008; 283:29882-7. [PMID: 18703499 DOI: 10.1074/jbc.m804742200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The high affinity of IgE for its receptor, FcepsilonRI (K(a) approximately 10(10) M(-1)), is responsible for the persistence of mast cell sensitization. Cross-linking of FcepsilonRI-bound IgE by multivalent allergen leads to cellular activation and release of pro-inflammatory mediators responsible for the symptoms of allergic disease. We previously demonstrated that limiting the IgE-FcepsilonRI interaction to just one of the two Cepsilon3 domains in IgE-Fc, which together constitute the high affinity binding site, results in 1000-fold reduced affinity. Such attenuation, effected by a small molecule binding to part of the IgE:FcepsilonRI interface or a distant allosteric site, rather than complete blocking of the interaction, may represent a viable approach to the treatment of allergic disease. However, the degree to which the interaction would need to be disrupted is unclear, because the importance of high affinity for immediate hypersensitivity has never been investigated. We have incorporated into human IgE a mutation, R334S, previously characterized in IgE-Fc, which reduces its affinity for FcepsilonRI approximately 50-fold. We have compared the ability of wild type and R334S IgE to stimulate allergen-induced mast cell activation in vitro and in vivo. We confirmed the expected difference in affinity between wild type and mutant IgE for FcepsilonRI (approximately 50-fold) and found that, in vitro, mast cell degranulation was reduced proportionately. The effect in vivo was also marked, with a 75% reduction in the passive cutaneous anaphylaxis response. We have therefore demonstrated that the high affinity of IgE for FcepsilonRI is critical to the allergic response, and that even moderate attenuation of this affinity has a substantial effect in vivo.
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Affiliation(s)
- James Hunt
- King's College London, Medical Research Council, Randall Division of Cell and Molecular Biophysics, Guy's Campus, London SE1 1UL, United Kingdom
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22
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Abstract
The spreading epidemic of allergies and asthma has heightened interest in IgE, the central player in the allergic response. The activity of IgE is associated with a network of proteins; prominent among these are its two principal receptors, FcepsilonRI (high-affinity Fc receptor for IgE) and CD23, as well as galectin-3 and several co-receptors for CD23, notably CD21 and various integrins. Here, we review recent progress in uncovering the structures of these proteins and their complexes, and in our understanding of how IgE exerts its effects and how its expression is regulated. The information that has emerged suggests new therapeutic directions for combating allergic disease.
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23
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Peters C, Bacher M, Buenemann CL, Kricek F, Rondeau JM, Weigand K. Conformationally constrained mimics of the membrane-proximal domain of Fc epsilonRIalpha. Chembiochem 2008; 8:1785-9. [PMID: 17828717 DOI: 10.1002/cbic.200700362] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Carsten Peters
- Novartis Institutes for BioMedical Research, Brunner Strasse 59, 1235 Vienna, Austria
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24
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Abstract
The high-affinity immunoglobulin (Ig)E receptor, FcepsilonRI, regulates the action of mast cells and basophils and therefore, regulates the expression of atopic disease. There have been several recent observations that demonstrate new behaviors for this receptor. The control of FcepsilonRI expression, control of cell function by FcepsilonRI, and expression of FcepsilonRI on other cell types are important new areas of understanding currently being explored.
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25
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Abstract
A central feature of allergic reactions is the aggregation of the high-affinity IgE receptor, FcepsilonRI, to initiate a change in the behavior of the cell expressing the receptor. It is now clear that a number of cell types can express this receptor, which broadens the biology that revolves around IgE antibody. It is also quite clear that the presence of monomeric IgE antibody alters the expression of FcepsilonRI. There remains considerable uncertainty about the importance of independent regulation of the FcepsilonRIbeta subunit or its splice variant beta(T), in terms of regulating both expression and function of FcepsilonRI. There is also only primitive understanding of the role of various polymorphisms in the subunit genes on the atopic phenotype. There are, however, many efforts being made to resolve these issues and to discover other factors that regulate expression of this receptor. Of particular interest for understanding the variation in expression in atopy among patients, the role of this receptor on non-mast cell/basophils will be important to elucidate.
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Affiliation(s)
- Donald Macglashan
- The Johns Hopkins Asthma and Allergy Center, 5501 Bayview Circle, Baltimore, MD 21224, USA.
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26
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Hunter TM, McNae IW, Liang X, Bella J, Parsons S, Walkinshaw MD, Sadler PJ. Protein recognition of macrocycles: binding of anti-HIV metallocyclams to lysozyme. Proc Natl Acad Sci U S A 2005; 102:2288-92. [PMID: 15701702 PMCID: PMC548988 DOI: 10.1073/pnas.0407595102] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The macrocyclic antiviral drug xylyl-bicyclam blocks entry of HIV into cells by targeting the CXCR4 coreceptor, a seven-helix transmembrane G-protein-coupled receptor. Its affinity for CXCR4 is enhanced by binding to Cu2+, Ni2+, or Zn2+. Metallocyclams have a rich configurational chemistry and proteins may bind selectively to specific metallocyclam configurations. Our studies of lysozyme reveal structural details of protein-metallocyclam interactions that are important for receptor recognition. Solution NMR studies show that Cu-cyclam interacts with specific tryptophan residues of lysozyme (Trp-62, Trp-63, and Trp-123). Two major binding sites for both Cu-cyclam and Cu2-xylyl-bicyclam were detected by x-ray crystallography. In the first site, Cu2+ in one cyclam ring of Cu2-xylyl-bicyclam adopts a trans configuration and is coordinated to a carboxylate oxygen of Asp-101, whereas for Cu-cyclam two ring NH groups form H bonds to the carboxylate oxygens of Asp-101, stabilizing an unusual cis (folded) cyclam configuration. For both complexes in this site, a cyclam ring is sandwiched between the indole side chains of two tryptophan residues (Trp-62 and Trp-63). In the second site, a trans cyclam ring is stacked on Trp-123 and H bonded to the backbone carbonyl of Gly-117. We show that there is a pocket in a model of the human CXCR4 coreceptor in which trans and cis configurations of metallobicyclam can bind by direct metal coordination to carboxylate side chains, cyclam-NH...carboxylate H bonding, together with hydrophobic interactions with tryptophan residues. These studies provide a structural basis for the design of macrocycles that bind stereospecifically to G-coupled and other protein receptors.
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Affiliation(s)
- Tina M Hunter
- School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, United Kingdom
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27
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Stamos J, Eigenbrot C, Nakamura GR, Reynolds ME, Yin J, Lowman HB, Fairbrother WJ, Starovasnik MA. Convergent Recognition of the IgE Binding Site on the High-Affinity IgE Receptor. Structure 2004; 12:1289-301. [PMID: 15242605 DOI: 10.1016/j.str.2004.04.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2003] [Revised: 03/31/2004] [Accepted: 04/26/2004] [Indexed: 11/18/2022]
Abstract
Two structurally distinct classes of peptides were recently identified by phage display that bind the high-affinity IgE receptor, FcepsilonRI, and block IgE binding and subsequent receptor activation. Both classes adopt highly stable structures in solution, one forming a beta hairpin, with the other forming a helical "zeta" structure. Despite these differences, the two classes bind competitively to the same site on the receptor. Structural analyses of both peptide-receptor complexes by NMR spectroscopy and/or X-ray crystallography reveal that the unrelated peptide scaffolds have nevertheless converged to present a similar three-dimensional surface to interact with FcepsilonRI and that their modes of interaction share a key feature of the IgE-FcepsilonRI complex, the proline/tryptophan sandwich.
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Affiliation(s)
- Jennifer Stamos
- Department of Protein Engineering, Genentech, Inc., One DNA Way, South San Francisco, CA 94080 USA.
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28
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Woof JM, Burton DR. Human antibody–Fc receptor interactions illuminated by crystal structures. Nat Rev Immunol 2004; 4:89-99. [PMID: 15040582 DOI: 10.1038/nri1266] [Citation(s) in RCA: 240] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Immunoglobulins couple the recognition of invading pathogens with the triggering of potent effector mechanisms for pathogen elimination. Different immunoglobulin classes trigger different effector mechanisms through interaction of immunoglobulin Fc regions with specific Fc receptors (FcRs) on immune cells. Here, we review the structural information that is emerging on three human immunoglobulin classes and their FcRs. New insights are provided, including an understanding of the antibody conformational adjustments that are required to bring effector cell and target cell membranes sufficiently close for efficient killing and signal transduction to occur. The results might also open up new possibilities for the design of therapeutic antibodies.
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Affiliation(s)
- Jenny M Woof
- Division of Pathology and Neuroscience, University of Dundee Medical School, Ninewells Hospital, Dundee DD1 9SY, UK.
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29
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Charles N, Monteiro RC, Benhamou M. p28, a novel IgE receptor-associated protein, is a sensor of receptor occupation by its ligand in mast cells. J Biol Chem 2004; 279:12312-8. [PMID: 14715661 DOI: 10.1074/jbc.m309456200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mast cells express the high affinity receptor for IgE (FcepsilonRI). Aggregation of this receptor by IgE and antigen leads to a signaling cascade resulting in the secretion of histamine, in the synthesis of other pro-inflammatory mediators such as leukotrienes and prostaglandins, and in the production of various cytokines, all of which participate in the development of the allergic reaction. In the last years, growing evidence accumulated that binding of IgEs to FcepsilonRI in itself induces active signals leading to mast cell survival, increased expression of FcepsilonRI, transient induction of histidine decarboxylase synthesis, and increased cell adhesion. The mechanisms underlying monomeric IgE signaling in the absence of receptor aggregation are still poorly understood. Here, we show that a protein of 28 kDa (p28) is physically and constitutively associated with FcepsilonRI in mast cells. Coimmunoprecipitation studies from (125)I surface-labeled cells demonstrated that this association involves at least 50% of membrane-expressed FcepsilonRI. After the addition of monomeric IgE to the cells, the p28.FcepsilonRI complex dissociates almost completely in less than 2 min. This dissociation is temperature-sensitive and is not due to the recruitment of additional proteins to the complex. Stripping bound IgE from the cells by acidic treatment promotes a rapid reassociation between p28 and FcepsilonRI. Altogether, these data are consistent with a conformational regulation of the complex. Thus, p28 is a sensor for FcepsilonRI occupation by IgE on mast cells, and its dissociation from the receptor could represent an early step of monomeric IgE signaling.
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Affiliation(s)
- Nicolas Charles
- INSERM EMI-0225, Faculté de Médecine Xavier Bichat, 16 rue Henri Huchard, 75870 Paris Cedex 18, France
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30
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Affiliation(s)
- Roald Nezlin
- Department of Immunology, Weizmann Institute of Science, Rehovot 76100, Israel
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31
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Gould HJ, Sutton BJ, Beavil AJ, Beavil RL, McCloskey N, Coker HA, Fear D, Smurthwaite L. The biology of IGE and the basis of allergic disease. Annu Rev Immunol 2003; 21:579-628. [PMID: 12500981 DOI: 10.1146/annurev.immunol.21.120601.141103] [Citation(s) in RCA: 440] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Allergic individuals exposed to minute quantities of allergen experience an immediate response. Immediate hypersensitivity reflects the permanent sensitization of mucosal mast cells by allergen-specific IgE antibodies bound to their high-affinity receptors (FcepsilonRI). A combination of factors contributes to such long-lasting sensitization of the mast cells. They include the homing of mast cells to mucosal tissues, the local synthesis of IgE, the induction of FcepsilonRI expression on mast cells by IgE, the consequent downregulation of FcgammaR (through an insufficiency of the common gamma-chains), and the exceptionally slow dissociation of IgE from FcepsilonRI. To understand the mechanism of the immediate hypersensitivity phenomenon, we need explanations of why IgE antibodies are synthesized in preference to IgG in mucosal tissues and why the IgE is so tenaciously retained on mast cell-surface receptors. There is now compelling evidence that the microenvironment of mucosal tissues of allergic disease favors class switching to IgE; and the exceptionally high affinity of IgE for FcepsilonRI can now be interpreted in terms of the recently determined crystal structures of IgE-FcepsilonRI and IgG-FcgammaR complexes. The rate of local IgE synthesis can easily compensate for the rate of the antibody dissociation from its receptors on mucosal mast cells. Effective mechanisms ensure that allergic reactions are confined to mucosal tissues, thereby minimizing the risk of systemic anaphylaxis.
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MESH Headings
- Allergens
- Amino Acid Sequence
- Animals
- Antigen-Presenting Cells/immunology
- B-Lymphocytes/immunology
- Blood Platelets/immunology
- Crystallography, X-Ray
- Disease Models, Animal
- Eosinophils/immunology
- Humans
- Hypersensitivity/etiology
- Hypersensitivity/immunology
- Immunoglobulin Class Switching
- Immunoglobulin E/chemistry
- Immunoglobulin E/genetics
- Immunoglobulin E/metabolism
- Models, Molecular
- Monocytes/immunology
- Nuclear Magnetic Resonance, Biomolecular
- Receptors, IgE/chemistry
- Receptors, IgE/genetics
- Receptors, IgE/metabolism
- Receptors, IgG/chemistry
- Receptors, IgG/metabolism
- Schistosomiasis/immunology
- T-Lymphocytes, Helper-Inducer/immunology
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Affiliation(s)
- Hannah J Gould
- The Randall Centre, King's College London, United Kingdom.
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32
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Vangelista L. Current progress in the understanding of IgE-FcepsilonRI interaction. Int Arch Allergy Immunol 2003; 131:222-33. [PMID: 12915765 DOI: 10.1159/000072134] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The last decade has seen a wealth of studies aimed at the characterization of the binding between IgE and its high-affinity receptor, FcepsilonRI. IgE-FcepsilonRI complex formation is a major molecular event in atopic allergy. IgE-FcepsilonRI binding connects allergen recognition to cellular triggering, ultimately leading to disease manifestations. Consequently, pharmacological intervention at this site is of universal relevance for atopic allergy. Until recent years, the complexity of IgE-FcepsilonRI binding, together with the difficulty in obtaining fully functional recombinant IgE and FcepsilonRI derivatives, often led to confusion and difficulty in data interpretation. Major advances in the understanding of this intricate protein-protein interaction have now been accomplished. Most of the current knowledge on the IgE-FcepsilonRI recognition mode derives from long-lasting efforts in the field of structural biology. Protein engineering, high-throughput screening, immunological and biochemical studies also made relevant contributions in this domain. The data accumulated to date predict that IgE and FcepsilonRI use their modular architecture to approach each other in an asymmetric stepwise manner determining a 1:1 stoichiometry. This recognition appears to be enhanced by conformational changes occurring upon binding, leading to the well-known high-affinity. In conclusion, the vast amount of high-quality data available broadened our knowledge on the IgE-FcepsilonRI system; however, the fine structural details of the recognition process are still largely hypothetical. More studies are necessary to provide the experimental comprehensive picture required to carefully design efficient drugs acting at the IgE-FcepsilonRI interface.
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Affiliation(s)
- Luca Vangelista
- Department of Biology and Genetics, University of Milan, Milan, Italy.
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33
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Herr AB, Ballister ER, Bjorkman PJ. Insights into IgA-mediated immune responses from the crystal structures of human FcalphaRI and its complex with IgA1-Fc. Nature 2003; 423:614-20. [PMID: 12768205 DOI: 10.1038/nature01685] [Citation(s) in RCA: 213] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2002] [Accepted: 04/07/2003] [Indexed: 11/08/2022]
Abstract
Immunoglobulin-alpha (IgA)-bound antigens induce immune effector responses by activating the IgA-specific receptor FcalphaRI (CD89) on immune cells. Here we present crystal structures of human FcalphaRI alone and in a complex with the Fc region of IgA1 (Fcalpha). FcalphaRI has two immunoglobulin-like domains that are oriented at approximately right angles to each other. Fcalpha resembles the Fcs of immunoglobulins IgG and IgE, but has differently located interchain disulphide bonds and external rather than interdomain N-linked carbohydrates. Unlike 1:1 FcgammaRIII:IgG and Fc epsilon RI:IgE complexes, two FcalphaRI molecules bind each Fcalpha dimer, one at each Calpha2-Calpha3 junction. The FcalphaRI-binding site on IgA1 overlaps the reported polymeric immunoglobulin receptor (pIgR)-binding site, which might explain why secretory IgA cannot initiate phagocytosis or bind to FcalphaRI-expressing cells in the absence of an integrin co-receptor.
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Affiliation(s)
- Andrew B Herr
- Division of Biology 114-96, California Institute of Technology, Pasadena, California 91125, USA
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Spivey AC, McKendrick J, Srikaran R, Helm BA. Solid-phase synthesis of an A-B loop mimetic of the Cepsilon3 domain of human IgE: macrocyclization by Sonogashira coupling. J Org Chem 2003; 68:1843-51. [PMID: 12608800 DOI: 10.1021/jo026693e] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The solid-phase synthesis of a cyclic peptide containing the 21-residue epitope found in the A-B loop of the Cepsilon3 domain of human immunoglobulin E has been carried out. The key macrocyclization step to form the 65-membered ring is achieved in approximately 15% yield via an "on-resin" Sonogashira coupling reaction which concomitantly installs a diphenylacetylene amino acid conformational constraint within the loop.
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Affiliation(s)
- Alan C Spivey
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, UK.
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Garman SC, Simcoke WN, Stowers AW, Garboczi DN. Structure of the C-terminal domains of merozoite surface protein-1 from Plasmodium knowlesi reveals a novel histidine binding site. J Biol Chem 2003; 278:7264-9. [PMID: 12493733 DOI: 10.1074/jbc.m210716200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The protozoan parasite Plasmodium causes malaria, with hundreds of millions of cases recorded annually. Protection against malaria infection can be conferred by antibodies against merozoite surface protein (MSP)-1, making it an attractive vaccine candidate. Here we present the structure of the C-terminal domains of MSP-1 (known as MSP-1(19)) from Plasmodium knowlesi. The structure reveals two tightly packed epidermal growth factor-like domains oriented head to tail. In domain 1, the molecule displays a histidine binding site formed primarily by a highly conserved tryptophan. The protein carries a pronounced overall negative charge primarily due to the large number of acidic groups in domain 2. To map protein binding surfaces on MSP-1(19), we have analyzed the crystal contacts in five different crystal environments, revealing that domain 1 is highly preferred in protein-protein interactions. A comparison of MSP-1(19) structures from P. knowlesi, P. cynomolgi, and P. falciparum shows that, although the overall protein folds are similar, the molecules show significant differences in charge distribution. We propose the histidine binding site in domain 1 as a target for inhibitors of protein binding to MSP-1, which might prevent invasion of the merozoite into red blood cells.
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Affiliation(s)
- Scott C Garman
- Structural Biology Section, Laboratory of Immunogenetics and Malaria Vaccine Development Unit, Laboratory of Parasitic Diseases, NIAID, National Institutes of Health, Rockville, Maryland 20852, USA.
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Metzger H, Eglite S, Haleem-Smith H, Reischl I, Torigoe C. Quantitative aspects of signal transduction by the receptor with high affinity for IgE. Mol Immunol 2002; 38:1207-11. [PMID: 12217385 DOI: 10.1016/s0161-5890(02)00065-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Identification of the major components, how these interact with each other, and the modifications that follow in the sequence of events triggered by the receptor with high affinity for IgE, is progressing rapidly. A new challenge is to understand these interactions quantitatively. We present the fundamentals of the mechanistic model we are testing through mathematical modeling. The object is to see if the predictions of the model fit with the experimental results.
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Affiliation(s)
- Henry Metzger
- Section on Chemical Immunology, Arthritis and Rheumatism Branch, Rm. 9N-228, 10 Center Drive, MSC 1820, NIAMS, NIH, Bethesda, MD 20892-1820, USA.
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Vangelista L, Cesco-Gaspere M, Lamba D, Burrone O. Efficient Folding of the FcεRI α-chain Membrane-proximal Domain D2 Depends on the Presence of the N-terminal Domain D1. J Mol Biol 2002; 322:815-25. [PMID: 12270716 DOI: 10.1016/s0022-2836(02)00853-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Human high affinity receptor for IgE is a membrane glycoprotein multichain complex presenting two extracellular Ig modules in its alpha-chain (D1D2). The receptor IgE binding region is located within the membrane-proximal module D2, while the N-terminal module D1 appears to promote an optimal receptor conformation for IgE binding. To understand the structural relationship between the two modules, we dissected FcepsilonRI alpha-chain into its discrete Ig units and expressed them in mammalian cells. Unexpectedly, D2 was secreted as a disulphide-linked dimer, while D1 was monomeric. Active secretion and full glycosylation of dimeric D2 suggest a native-like conformation of the protein, justifying the escape from the endoplasmic reticulum/Golgi quality control systems. We then propose a domain-swapping model for D2, in which two interdigitated polypeptide chains assume the overall conformation of two Ig modules, as observed for rat CD2 N-terminal domain. Fusion of an unrelated Ig fold moiety at the N terminus of D2 did not interfere with its dimerisation. While D1D2 assumes a correct fold, co-expression of both isolated domains in the same cell did not restore monomeric folding of D2. Thus, D1 appears to assist the appropriate folding of FcepsilonRI alpha-chain, acting as an uncleavable intramolecular chaperone-like block towards D2.
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Affiliation(s)
- Luca Vangelista
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, I-34012 Trieste, Italy
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Wan T, Beavil RL, Fabiane SM, Beavil AJ, Sohi MK, Keown M, Young RJ, Henry AJ, Owens RJ, Gould HJ, Sutton BJ. The crystal structure of IgE Fc reveals an asymmetrically bent conformation. Nat Immunol 2002; 3:681-6. [PMID: 12068291 DOI: 10.1038/ni811] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The distinguishing structural feature of immunoglobulin E (IgE), the antibody responsible for allergic hypersensitivity, is the C epsilon 2 domain pair that replaces the hinge region of IgG. The crystal structure of the IgE Fc (constant fragment) at a 2.6-A resolution has revealed these domains. They display a distinctive, disulfide-linked Ig domain interface and are folded back asymmetrically onto the C epsilon 3 and C epsilon 4 domains, which causes an acute bend in the IgE molecule. The structure implies that a substantial conformational change involving C epsilon 2 must accompany binding to the mast cell receptor Fc epsilon RI. This may be the basis of the exceptionally slow dissociation rate of the IgE-Fc epsilon RI complex and, thus, of the ability of IgE to cause persistent allergic sensitization of mast cells.
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Affiliation(s)
- Tommy Wan
- The Randall Centre, King's College London, New Hunt's House, London SE1 1UL, UK
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Abstract
As immunology developed into a discrete discipline, the principal experimental efforts were directed towards uncovering the molecular basis of the specificity exhibited by antibodies and the mechanism by which antigens induced their production. Less attention was given to how antibodies carry out some of their effector functions, although this subject presents an interesting protein-chemical and evolutionary problem; that is, how does a family of proteins that can bind a virtually infinite variety of ligands, many of which the species producing that protein has never encountered, reproducibly initiate an appropriate response? The experimental data persuasively suggested that aggregation of the antibody was a necessary and likely sufficient initiating event, but this only begged the question: how does aggregation induce a response? I used the IgE:mast cell system as a paradigm to investigate this subject. Data from our own group and from many others led to a molecular model that appears to explain how a cell 'senses' that antigen has reacted with the IgE. The model is directly applicable to one of the fundamental questions cited above, i.e. the mechanism by which antigens induce the production of antibodies. Although the model is conceptually simple, incorporating the actual molecular events into a quantitatively accurate scheme represents an enormous challenge.
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Affiliation(s)
- Henry Metzger
- Section on Chemical Immunology, Arthritis and Rheumatism Branch, NIAMS, NIH, Bethesda, MD 20892-1820, USA.
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Allison TJ, Garboczi DN. Structure of gammadelta T cell receptors and their recognition of non-peptide antigens. Mol Immunol 2002; 38:1051-61. [PMID: 11955597 DOI: 10.1016/s0161-5890(02)00034-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The gammadelta T cell receptors (TCRs) and alphabeta TCRs are similar in both sequence and structure; however, gammadelta+ and alphabeta+ T cells are not merely similar lymphocytes with subtly different receptors. These cell types differ in several ways, including the types of antigens recognized, the mechanism of antigen presentation and recognition and the mechanism and kinetics of downstream signaling events. gammadelta TCRs can directly recognize antigens in the form of intact proteins or non-peptidic compounds, unlike alphabeta TCRs which recognize peptide antigens bound to major histocompatibility complex molecules (MHC). One of the major classes of human gammadelta+ T cells expresses Vgamma9Vdelta2 TCRs which recognize pyrophosphomonoester, alkylamine and aminobisphosphonate antigens. This review focuses on the recently determined structure of a Vgamma9Vdelta2 TCR, with emphasis on antigen recognition and receptor signaling.
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Affiliation(s)
- Timothy J Allison
- Structural Biology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, 12441 Parklawn Drive, Rockville, MD 20852, USA
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Wurzburg BA, Jardetzky TS. Structural insights into the interactions between human IgE and its high affinity receptor FcepsilonRI. Mol Immunol 2002; 38:1063-72. [PMID: 11955598 DOI: 10.1016/s0161-5890(02)00035-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The interaction of IgE antibodies with the high affinity IgE receptor, FcepsilonRI, is a key step in the initiation of anti-parasitic immunity and allergic reactions. Recent structural studies of the receptor, the IgE-Fc and the IgE-Fc:FcepsilonRI complex have revealed how these two proteins interact to prime mast cell responses to antigen. The structures have revealed a novel arrangement for the FcepsilonRI ectodomains that is also observed in homologous members of this antibody receptor family. The crystal structure of the IgE-Fc:FcepsilonRI complex clarified how a 1:1 complex between the antibody and receptor is formed, with the receptor binding each chain of the antibody Fc dimer. The IgE-Fc structure in the absence of the receptor revealed the potential for large conformational rearrangements within the IgE that may affect receptor binding. These studies provide the basis for further investigation of the specificity of antibody:receptor binding and for the development of new treatments for allergic hypersensitivities.
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Affiliation(s)
- Beth A Wurzburg
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, IL 60208-3500, USA
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Iwasaki A, Doi T, Umetani M, Watanabe M, Suda M, Hattori Y, Nagoya T. Affinity improvement of the high-affinity immunoglobulin E receptor by phage display. Biochem Biophys Res Commun 2002; 293:542-8. [PMID: 12054635 DOI: 10.1016/s0006-291x(02)00261-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The immunoglobulin E (IgE)-binding site of its high-affinity receptor is localized in the second immunoglobulin-like domain (D2) of the alpha-subunit (Fc epsilon RI alpha). In this study, the randomized pentapeptides were introduced between Glu(132) and Ile(138) of Fc epsilon RI alpha D2 and displayed on a filamentous phage. After eight rounds of panning, a phage clone having a mutation of Asp(135)Tyr(136)Met(137) in Fc epsilon RI alpha D2 was obtained. The binding affinity of the mutant phages to immobilized IgE was approximately 500 times higher than that of the wild type. The mutant phages competitively inhibited the binding of IgE to the soluble receptor at a 50% inhibition (IC(50)) value of 116 pM. The mutant Fc epsilon RI alpha D2, which had been expressed as a fusion protein with glutathione S-transferase in Escherichia coli, also showed higher IgE-binding capacity than the wild type. The mutant Fc epsilon RI alpha D2 is expected to manifest its improved IgE-binding affinity together with any fusion partner.
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Affiliation(s)
- Akio Iwasaki
- Institute of Applied Biochemistry, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
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Nakamura GR, Reynolds ME, Chen YM, Starovasnik MA, Lowman HB. Stable "zeta" peptides that act as potent antagonists of the high-affinity IgE receptor. Proc Natl Acad Sci U S A 2002; 99:1303-8. [PMID: 11830661 PMCID: PMC122185 DOI: 10.1073/pnas.022635599] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recently we described a family of peptides, unrelated in sequence to IgE, that form stable beta-hairpins in solution and inhibit IgE activity in the microM range [Nakamura, G. R., Starovasnik, M. A., Reynolds, M. E. & Lowman, H. B. (2001) Biochemistry 40, 9828-9835]. Using an expanded set of peptide-phage libraries, we found a simpler motif, X(2)CPX(2)CYX, for binding to the high-affinity IgE receptor. In solution, one of these peptides spontaneously formed a covalent antiparallel dimer. We subsequently linked these monomers in a single-chain construct on phage and optimized receptor binding. Ultimately, peptides with 30 nM affinity were produced. NMR studies showed that the peptide adopts a stable fold consisting of two "zeta" (zeta)-shaped moieties. Structure-activity analyses reveal a single binding site created by the zeta-dimer, with two tyrosine residues important for structural stability and two proline residues important for Fc epsilon RI binding. The peptides inhibit histamine release from cultured cells and are extremely stable in biological fluids. The zeta peptides appear to act as competitive IgE inhibitors and suggest possibilities for design of novel IgE antagonists.
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Affiliation(s)
- Gerald R Nakamura
- Department of Protein Engineering, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
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Metzler DE, Metzler CM, Sauke DJ. Biochemical Defense Mechanisms. Biochemistry 2001. [DOI: 10.1016/b978-012492543-4/50034-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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