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Flanagan SP, Fogel R, Edkins AL, Ho LSJ, Limson J. Nonspecific nuclear uptake of anti-MUC1 aptamers by dead cells: the role of cell viability monitoring in aptamer targeting of membrane-bound protein cancer biomarkers. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2021; 13:1191-1203. [PMID: 33605950 DOI: 10.1039/d0ay01878c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Most aptamers targeting cell-expressed antigens are intended for in vivo application, however, these sequences are commonly generated in vitro against synthetic oligopeptide epitopes or recombinant proteins. As these in vitro analogues frequently do not mimic the in vivo target within an endogenous environment, the evolved aptamers are often prone to nonspecific binding. The presence of dead cells and cellular debris further complicate aptamer targeting, due to their high nonspecific affinities to single-stranded DNA. Despite these known limitations, assessment of cell viability and/or the removal of dead cells is rarely applied as part of the methodology during in vivo testing of aptamer binding. Furthermore, the extent and route(s) by which dead cells uptake existing aptamers remains to be determined in the literature. For this purpose, the previously reported aptamer sequences 5TR1, 5TR4, 5TRG2 and S22 - enriched against the MUC1 tumour marker of the mucin glycoprotein family - were used as model sequences to evaluate the influence of cell viability and the presence of nontarget cell-expressed protein on aptamer binding to the MUC1 expressing human cancer cell lines MCF-7, Hs578T, SW480, and SW620. From fluorescence microscopy analysis, all tested aptamers demonstrated extensive nonspecific uptake within the nuclei of dead cells with compromised membrane integrities. Using fluorescent-activated cell sorting (FACS), the inclusion of excess double-stranded DNA as a blocking agent showed no effect on nonspecific aptamer uptake by dead cells. Further nonspecific binding to cell-membrane bound and intracellular protein was evident for each aptamer sequence, as assessed by southwestern blotting and FACS. These factors likely contributed to the ∼120-fold greater binding response of the 5TR1 aptamer to dead MCF-7 cells over equivalent live cell populations. The identification of dead cells and cellular debris using viability stains and the subsequent exclusion of these cells from FACS analysis was identified as an essential requirement for the evaluation of aptamer binding specificity to live cell populations of the cancer cell lines MCF-7, Hs578T and SW480. The research findings stress the importance of dead cell uptake and more comprehensive cell viability screening to validate novel aptamer sequences for diagnostic and therapeutic application.
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Wakui H, Tanaka Y, Ose T, Matsumoto I, Kato K, Min Y, Tachibana T, Sato M, Naruchi K, Martin FG, Hinou H, Nishimura SI. A straightforward approach to antibodies recognising cancer specific glycopeptidic neoepitopes. Chem Sci 2020; 11:4999-5006. [PMID: 34122956 PMCID: PMC8159228 DOI: 10.1039/d0sc00317d] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 11/18/2020] [Accepted: 04/23/2020] [Indexed: 12/14/2022] Open
Abstract
Aberrantly truncated immature O-glycosylation in proteins occurs in essentially all types of epithelial cancer cells, which was demonstrated to be a common feature of most adenocarcinomas and strongly associated with cancer proliferation and metastasis. Although extensive efforts have been made toward the development of anticancer antibodies targeting MUC1, one of the most studied mucins having cancer-relevant immature O-glycans, no anti-MUC1 antibody recognises carbohydrates and the proximal MUC1 peptide region, concurrently. Here we present a general strategy that allows for the creation of antibodies interacting specifically with glycopeptidic neoepitopes by using homogeneous synthetic MUC1 glycopeptides designed for the streamlined process of immunization, antibody screening, three-dimensional structure analysis, epitope mapping and biochemical analysis. The X-ray crystal structure of the anti-MUC1 monoclonal antibody SN-101 complexed with the antigenic glycopeptide provides for the first time evidence that SN-101 recognises specifically the essential epitope by forming multiple hydrogen bonds both with the proximal peptide and GalNAc linked to the threonine residue, concurrently. Remarkably, the structure of the MUC1 glycopeptide in complex with SN-101 is identical to its solution NMR structure, an extended conformation induced by site-specific glycosylation. We demonstrate that this method accelerates dramatically the development of a new class of designated antibodies targeting a variety of "dynamic neoepitopes" elaborated by disease-specific O-glycosylation in the immunodominant mucin domains and mucin-like sequences found in intrinsically disordered regions of many proteins.
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Affiliation(s)
- Hajime Wakui
- Field of Drug Discovery Research, Faculty of Advanced Life Science, Graduate School of Life Science, Hokkaido University N21 W11, Kita-ku Sapporo 001-0021 Japan
| | - Yoshikazu Tanaka
- Graduate School of Life Sciences, Tohoku University 2-1-1 Katahira, Aoba-ku Sendai 980-8577 Japan
| | - Toyoyuki Ose
- Field of X-ray Structural Biology, Faculty of Advanced Life Science, Graduate School of Life Science, Hokkaido University N10 W8, Kita-ku Sapporo 060-0810 Japan
| | - Isamu Matsumoto
- Field of X-ray Structural Biology, Faculty of Advanced Life Science, Graduate School of Life Science, Hokkaido University N10 W8, Kita-ku Sapporo 060-0810 Japan
| | - Koji Kato
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University 3-1-1, Tsushima-naka, Kita-ku Okayama 700-8530 Japan
| | - Yao Min
- Field of X-ray Structural Biology, Faculty of Advanced Life Science, Graduate School of Life Science, Hokkaido University N10 W8, Kita-ku Sapporo 060-0810 Japan
| | - Taro Tachibana
- Department of Bioengineering, Graduate School of Engineering, Osaka City University Sumiyoshi-ku Osaka 558-8585 Japan
| | - Masaharu Sato
- Medicinal Chemistry Pharmaceuticals, Co., Ltd. N9 W15, Chuo-ku Sapporo 060-0009 Japan
| | - Kentaro Naruchi
- Medicinal Chemistry Pharmaceuticals, Co., Ltd. N9 W15, Chuo-ku Sapporo 060-0009 Japan
| | - Fayna Garcia Martin
- Field of Drug Discovery Research, Faculty of Advanced Life Science, Graduate School of Life Science, Hokkaido University N21 W11, Kita-ku Sapporo 001-0021 Japan
| | - Hiroshi Hinou
- Field of Drug Discovery Research, Faculty of Advanced Life Science, Graduate School of Life Science, Hokkaido University N21 W11, Kita-ku Sapporo 001-0021 Japan
| | - Shin-Ichiro Nishimura
- Field of Drug Discovery Research, Faculty of Advanced Life Science, Graduate School of Life Science, Hokkaido University N21 W11, Kita-ku Sapporo 001-0021 Japan
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3
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Impaired O-Glycosylation at Consecutive Threonine TTX Motifs in Mucins Generates Conformationally Restricted Cancer Neoepitopes. Biochemistry 2020; 59:1221-1241. [PMID: 32155332 DOI: 10.1021/acs.biochem.0c00007] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Autoantibody signatures of circulating mucin fragments stem from cancer tissues, and microenvironments are promising biomarkers for cancer diagnosis and therapy. This study highlights dynamic epitopes generated by aberrantly truncated immature O-glycosylation at consecutive threonine motifs (TTX) found in mucins and intrinsically disordered proteins (IDPs). NMR analysis of synthetic mucin models having glycosylated TTX motifs and colonic MUC2 tandem repeats (TRs) containing TTP and TTL moieties unveils a general principle that O-glycosylation at TTX motifs generates a highly extended and rigid conformation in IDPs. We demonstrate that the specific conformation of glycosylated TTX motifs in MUC2 TRs is rationally rearranged by concerted motions of multiple dihedral angles and noncovalent interactions between the carbohydrate and peptide region. Importantly, this canonical conformation of glycosylated TTX motifs minimizes steric crowding of glycans attached to threonine residues, in which O-glycans possess restricted orientations permitting further sugar extension. An antiadhesive microarray displaying synthetic MUC2 derivatives elicited the presence of natural autoantibodies to MUC2 with impaired O-glycosylation at TTX motifs in sera of healthy volunteers and patients diagnosed with early stage colorectal cancer (CRC). Interestingly, autoantibody levels in sera of the late stage CRC patients were distinctly lower than those of early stage CRC and normal individuals, indicating that the anti-MUC2 humoral response to MUC2 neoepitopes correlates inversely with the CRC stage of patients. Our results uncovered the structural basis of the creation of dynamic epitopes by immature O-glycosylation at TTX motifs in mucins that facilitates the identification of high-potential targets for cancer diagnosis and therapy.
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Singh J, Her C, Supekar N, Boons G, Krishnan VV, Brooks CL. Role of glycosylation on the ensemble of conformations in the MUC1 immunodominant epitope. J Pept Sci 2019; 26:e3229. [DOI: 10.1002/psc.3229] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 10/08/2019] [Accepted: 10/16/2019] [Indexed: 01/09/2023]
Affiliation(s)
- Jaideep Singh
- Department of ChemistryCalifornia State University 2555 E San Ramon Avenue Fresno CA 93740 USA
| | - Cheenou Her
- Department of ChemistryCalifornia State University 2555 E San Ramon Avenue Fresno CA 93740 USA
| | - Nitin Supekar
- Department of ChemistryThe University of Georgia 140 Cedar Street Athens GA 30602 USA
- Complex Carbohydrate Research CenterThe University of Georgia 315 Riverbend Road Athens GA 3062 USA
| | - Geert‐Jan Boons
- Department of ChemistryThe University of Georgia 140 Cedar Street Athens GA 30602 USA
- Complex Carbohydrate Research CenterThe University of Georgia 315 Riverbend Road Athens GA 3062 USA
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular ResearchUtrecht University Universiteitsweg 99 3584 CG Utrecht The Netherlands
| | - Viswanathan V. Krishnan
- Department of ChemistryCalifornia State University 2555 E San Ramon Avenue Fresno CA 93740 USA
- Department of Pathology & Laboratory MedicineUniversity of California Davis School of Medicine 95616 Davis CA
| | - Cory L. Brooks
- Department of ChemistryCalifornia State University 2555 E San Ramon Avenue Fresno CA 93740 USA
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Products of Chemoenzymatic Synthesis Representing MUC1 Tandem Repeat Unit with T-, ST- or STn-antigen Revealed Distinct Specificities of Anti-MUC1 Antibodies. Sci Rep 2019; 9:16641. [PMID: 31719620 PMCID: PMC6851390 DOI: 10.1038/s41598-019-53052-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 10/25/2019] [Indexed: 12/15/2022] Open
Abstract
Anti-mucin1 (MUC1) antibodies have long been used clinically in cancer diagnosis and therapy and specific bindings of some of them are known to be dependent on the differential glycosylation of MUC1. However, a systematic comparison of the binding specificities of anti-MUC1 antibodies was not previously conducted. Here, a total of 20 glycopeptides including the tandem repeat unit of MUC1, APPAHGVTSAPDTRPAPGSTAPPAHGV with GalNAc (Tn-antigen), Galβ1-3GalNAc (T-antigen), NeuAcα2-3Galβ1-3GalNAc (sialyl-T-antigen), or NeuAcα2-6GalNAc (sialyl-Tn-antigen) at each threonine or serine residue were prepared by a combination of chemical glycopeptide synthesis and enzymatic extension of carbohydrate chains. These glycopeptides were tested by the enzyme-linked immunosorbent assay (ELISA) for their capacity to bind 13 monoclonal antibodies (mAbs) known to be specific for MUC1. The results indicated that anti-MUC1 mAbs have diverse specificities but can be classified into a few characteristic groups based on their binding pattern toward glycopeptides in some cases having a specific glycan at unique glycosylation sites. Because the clinical significance of some of these antibodies was already established, the structural features identified by these antibodies as revealed in the present study should provide useful information relevant to their further clinical use and the biological understanding of MUC1.
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Compañón I, Guerreiro A, Mangini V, Castro-López J, Escudero-Casao M, Avenoza A, Busto JH, Castillón S, Jiménez-Barbero J, Asensio JL, Jiménez-Osés G, Boutureira O, Peregrina JM, Hurtado-Guerrero R, Fiammengo R, Bernardes GJL, Corzana F. Structure-Based Design of Potent Tumor-Associated Antigens: Modulation of Peptide Presentation by Single-Atom O/S or O/Se Substitutions at the Glycosidic Linkage. J Am Chem Soc 2019; 141:4063-4072. [PMID: 30726084 DOI: 10.1021/jacs.8b13503] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
GalNAc-glycopeptides derived from mucin MUC1 are an important class of tumor-associated antigens. α- O-glycosylation forces the peptide to adopt an extended conformation in solution, which is far from the structure observed in complexes with a model anti-MUC1 antibody. Herein, we propose a new strategy for designing potent antigen mimics based on modulating peptide/carbohydrate interactions by means of O → S/Se replacement at the glycosidic linkage. These minimal chemical modifications bring about two key structural changes to the glycopeptide. They increase the carbohydrate-peptide distance and change the orientation and dynamics of the glycosidic linkage. As a result, the peptide acquires a preorganized and optimal structure suited for antibody binding. Accordingly, these new glycopeptides display improved binding toward a representative anti-MUC1 antibody relative to the native antigens. To prove the potential of these glycopeptides as tumor-associated MUC1 antigen mimics, the derivative bearing the S-glycosidic linkage was conjugated to gold nanoparticles and tested as an immunogenic formulation in mice without any adjuvant, which resulted in a significant humoral immune response. Importantly, the mice antisera recognize cancer cells in biopsies of breast cancer patients with high selectivity. This finding demonstrates that the antibodies elicited against the mimetic antigen indeed recognize the naturally occurring antigen in its physiological context. Clinically, the exploitation of tumor-associated antigen mimics may contribute to the development of cancer vaccines and to the improvement of cancer diagnosis based on anti-MUC1 antibodies. The methodology presented here is of general interest for applications because it may be extended to modulate the affinity of biologically relevant glycopeptides toward their receptors.
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Affiliation(s)
- Ismael Compañón
- Departamento de Química , Universidad de La Rioja , Centro de Investigación en Síntesis Química , 26006 Logroño , Spain
| | - Ana Guerreiro
- Instituto de Medicina Molecular, Faculdade de Medicina , Universidade de Lisboa , Avenida Professor Egas Moniz , 1649-028 Lisboa , Portugal
| | - Vincenzo Mangini
- Center for Biomolecular Nanotechnologies@UniLe , Istituto Italiano di Tecnologia (IIT) , 73010 Arnesano , Lecce , Italy
| | - Jorge Castro-López
- Institute of Biocomputation and Physics of Complex Systems (BIFI) , University of Zaragoza , BIFI-IQFR (CSIC), Fundación ARAID , 50018 Zaragoza , Spain
| | - Margarita Escudero-Casao
- Departament de Química Analítica i Química Orgànica, Facultat de Química , Universitat Rovira i Virgili , 43007 Tarragona , Spain
| | - Alberto Avenoza
- Departamento de Química , Universidad de La Rioja , Centro de Investigación en Síntesis Química , 26006 Logroño , Spain
| | - Jesús H Busto
- Departamento de Química , Universidad de La Rioja , Centro de Investigación en Síntesis Química , 26006 Logroño , Spain
| | - Sergio Castillón
- Departament de Química Analítica i Química Orgànica, Facultat de Química , Universitat Rovira i Virgili , 43007 Tarragona , Spain
| | - Jesús Jiménez-Barbero
- CIC bioGUNE , Bizkaia Technology Park , Building 801A , 48170 Derio , Spain.,Ikerbasque , Basque Foundation for Science , Maria Diaz de Haro 13 , 48009 Bilbao , Spain.,Department of Organic Chemistry II, Faculty of Science & Technology , University of the Basque Country , 48940 Leioa , Spain
| | - Juan L Asensio
- Instituto de Química Orgánica General , IQOG-CSIC , 28006 Madrid , Spain
| | - Gonzalo Jiménez-Osés
- Departamento de Química , Universidad de La Rioja , Centro de Investigación en Síntesis Química , 26006 Logroño , Spain.,CIC bioGUNE , Bizkaia Technology Park , Building 801A , 48170 Derio , Spain
| | - Omar Boutureira
- Departament de Química Analítica i Química Orgànica, Facultat de Química , Universitat Rovira i Virgili , 43007 Tarragona , Spain
| | - Jesús M Peregrina
- Departamento de Química , Universidad de La Rioja , Centro de Investigación en Síntesis Química , 26006 Logroño , Spain
| | - Ramón Hurtado-Guerrero
- Institute of Biocomputation and Physics of Complex Systems (BIFI) , University of Zaragoza , BIFI-IQFR (CSIC), Fundación ARAID , 50018 Zaragoza , Spain
| | - Roberto Fiammengo
- Center for Biomolecular Nanotechnologies@UniLe , Istituto Italiano di Tecnologia (IIT) , 73010 Arnesano , Lecce , Italy
| | - Gonçalo J L Bernardes
- Instituto de Medicina Molecular, Faculdade de Medicina , Universidade de Lisboa , Avenida Professor Egas Moniz , 1649-028 Lisboa , Portugal.,Department of Chemistry , University of Cambridge , Lensfield Road , CB2 1EW Cambridge , U.K
| | - Francisco Corzana
- Departamento de Química , Universidad de La Rioja , Centro de Investigación en Síntesis Química , 26006 Logroño , Spain
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7
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8
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Zhou D, Xu L, Huang W, Tonn T. Epitopes of MUC1 Tandem Repeats in Cancer as Revealed by Antibody Crystallography: Toward Glycopeptide Signature-Guided Therapy. Molecules 2018; 23:molecules23061326. [PMID: 29857542 PMCID: PMC6099590 DOI: 10.3390/molecules23061326] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 05/20/2018] [Accepted: 05/22/2018] [Indexed: 02/06/2023] Open
Abstract
Abnormally O-glycosylated MUC1 tandem repeat glycopeptide epitopes expressed by multiple types of cancer have long been attractive targets for therapy in the race against genetic mutations of tumor cells. Glycopeptide signature-guided therapy might be a more promising avenue than mutation signature-guided therapy. Three O-glycosylated peptide motifs, PDTR, GSTA, and GVTS, exist in a tandem repeat HGVTSAPDTRPAPGSTAPPA, containing five O-glycosylation sites. The exact peptide and sugar residues involved in antibody binding are poorly defined. Co-crystal structures of glycopeptides and respective monoclonal antibodies are very few. Here we review 3 groups of monoclonal antibodies: antibodies which only bind to peptide portion, antibodies which only bind to sugar portion, and antibodies which bind to both peptide and sugar portions. The antigenicity of peptide and sugar portions of glyco-MUC1 tandem repeat were analyzed according to available biochemical and structural data, especially the GSTA and GVTS motifs independent from the most studied PDTR. Tn is focused as a peptide-modifying residue in vaccine design, to induce glycopeptide-binding antibodies with cross reactivity to Tn-related tumor glycans, but not glycans of healthy cells. The unique requirement for the designs of antibody in antibody-drug conjugate, bi-specific antibodies, and chimeric antigen receptors are also discussed.
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Affiliation(s)
- Dapeng Zhou
- Shanghai Pulmonary Hospital Affiliated with Tongji University School of Medicine, Shanghai 200092, China.
| | - Lan Xu
- Laboratory of Antibody Structure, Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201203, China.
| | - Wei Huang
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences and iHuman Institute, ShanghaiTech University, Shanghai 201203, China.
| | - Torsten Tonn
- Institute for Transfusion Medicine Dresden, German Red Cross Blood Donation Service North-East, D-01307 Dresden, Germany.
- Medical Faculty, Carl Gustav Carus Technical University Dresden, D-01307 Dresden, Germany.
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9
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Movahedin M, Brooks TM, Supekar NT, Gokanapudi N, Boons GJ, Brooks CL. Glycosylation of MUC1 influences the binding of a therapeutic antibody by altering the conformational equilibrium of the antigen. Glycobiology 2018; 27:677-687. [PMID: 28025250 DOI: 10.1093/glycob/cww131] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 12/14/2016] [Indexed: 12/30/2022] Open
Abstract
In cancer cells, the glycoprotein Mucin 1 (MUC1) undergoes abnormal, truncated glycosylation. The truncated glycosylation exposes cryptic peptide epitopes that can be recognized by antibodies. Since these immunogenic regions are cancer specific, they represent ideal targets for therapeutic antibodies. We investigated the role of tumor-specific glycosylation on antigen recognition by the therapeutic antibody AR20.5. We explored the affinity of AR20.5 to a synthetic cancer-specific MUC1 glycopeptide and peptide. The antibody bound to the glycopeptide with an order of magnitude stronger affinity than the naked peptide. Given these results, we postulated that AR20.5 must specifically bind the carbohydrate as well as the peptide. Using X-ray crystallography, we examined this hypothesis by determining the structure of AR20.5 in complex with both peptide and glycopeptide. Surprisingly, the structure revealed that the carbohydrate did not form any specific polar contacts with the antibody. The high affinity of AR20.5 for the glycopeptide and the lack of specific binding contacts support a hypothesis that glycosylation of MUC1 stabilizes an extended bioactive conformation of the peptide recognized by the antibody. Since high affinity binding of AR20.5 to the MUC1 glycopeptide may not driven by specific antibody-antigen contacts, but rather evidence suggests that glycosylation alters the conformational equilibrium of the antigen, which allows the antibody to select the correct conformation. This study suggests a novel mechanism of antibody-antigen interaction and also suggests that glycosylation of MUC1 is important for the generation of high affinity therapeutic antibodies.
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Affiliation(s)
- Mohammadreza Movahedin
- Department of Chemistry, California State University Fresno, 2555 E San Ramon Ave, Fresno, CA 93740, USA
| | - Teresa M Brooks
- Department of Chemistry, California State University Fresno, 2555 E San Ramon Ave, Fresno, CA 93740, USA
| | - Nitin T Supekar
- Complex Carbohydrate Research Center, 315 Riverbend Road, Athens, GA 30602, USA.,Department of Chemistry, University of Georgia, 140 Cedar street, Athens, GA 30602, USA
| | - Naveen Gokanapudi
- Department of Chemistry, California State University Fresno, 2555 E San Ramon Ave, Fresno, CA 93740, USA
| | - Geert-Jan Boons
- Complex Carbohydrate Research Center, 315 Riverbend Road, Athens, GA 30602, USA.,Department of Chemistry, University of Georgia, 140 Cedar street, Athens, GA 30602, USA.,Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, and Bijvoet Center for Biomolecular Research, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Cory L Brooks
- Department of Chemistry, California State University Fresno, 2555 E San Ramon Ave, Fresno, CA 93740, USA
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Martínez-Sáez N, Peregrina JM, Corzana F. Principles of mucin structure: implications for the rational design of cancer vaccines derived from MUC1-glycopeptides. Chem Soc Rev 2018; 46:7154-7175. [PMID: 29022615 DOI: 10.1039/c6cs00858e] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cancer is currently one of the world's most serious public health problems. Significant efforts are being made to develop new strategies that can eradicate tumours selectively without detrimental effects to healthy cells. One promising approach is focused on the design of vaccines that contain partially glycosylated mucins in their formulation. Although some of these vaccines are in clinical trials, a lack of knowledge about the molecular basis that governs the antigen presentation, and the interactions between antigens and the elicited antibodies has limited their success thus far. This review focuses on the most significant milestones achieved to date in the conformational analysis of tumour-associated MUC1 derivatives both in solution and bound to antibodies. The effect that the carbohydrate scaffold has on the peptide backbone structure and the role of the sugar in molecular recognition by antibodies are emphasised. The outcomes summarised in this review may be a useful guide to develop new antigens for the design of cancer vaccines in the near future.
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Affiliation(s)
- Nuria Martínez-Sáez
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006 Logroño, Spain.
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11
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Leiria Campo V, Riul TB, Oliveira Bortot L, Martins-Teixeira MB, Fiori Marchiori M, Iaccarino E, Ruvo M, Dias-Baruffi M, Carvalho I. A Synthetic MUC1 Glycopeptide Bearing βGalNAc-Thr as a Tn Antigen Isomer Induces the Production of Antibodies against Tumor Cells. Chembiochem 2017; 18:527-538. [PMID: 28068458 DOI: 10.1002/cbic.201600473] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 01/05/2017] [Indexed: 01/01/2023]
Abstract
This study presents the synthesis of the novel protected O-glycosylated amino acid derivatives 1 and 2, containing βGalNAc-SerOBn and βGalNAc-ThrOBn units, respectively, as mimetics of the natural Tn antigen (αGalNAc-Ser/Thr), along with the solid-phase assembly of the glycopeptides NHAcSer-Ala-Pro-Asp-Thr[αGalNAc]-Arg-Pro-Ala-Pro-Gly-BSA (3-BSA) and NHAcSer-Ala-Pro-Asp-Thr[βGalNAc]-Arg-Pro-Ala-Pro-Gly-BSA (4-BSA), bearing αGalNAc-Thr or βGalNAc-Thr units, respectively, as mimetics of MUC1 tumor mucin glycoproteins. According to ELISA tests, immunizations of mice with βGalNAc-glycopeptide 4-BSA induced higher sera titers (1:320 000) than immunizations with αGalNAc-glycopeptide 3-BSA (1:40 000). Likewise, flow cytometry assays showed higher capacity of the obtained anti-glycopeptide 4-BSA antibodies to recognize MCF-7 tumor cells. Cross-recognition between immunopurified anti-βGalNAc antibodies and αGalNAc-glycopeptide and vice versa was also verified. Lastly, molecular dynamics simulations and surface plasmon resonance (SPR) showed that βGalNAc-glycopeptide 4 can interact with a model antitumor monoclonal antibody (SM3). Taken together, these data highlight the improved immunogenicity of the unnatural glycopeptide 4-BSA, bearing βGalNAc-Thr as Tn antigen isomer.
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Affiliation(s)
- Vanessa Leiria Campo
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. Café S/N, CEP, 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - Thalita B Riul
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. Café S/N, CEP, 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - Leandro Oliveira Bortot
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. Café S/N, CEP, 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - Maristela B Martins-Teixeira
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. Café S/N, CEP, 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - Marcelo Fiori Marchiori
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. Café S/N, CEP, 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - Emanuela Iaccarino
- Istituto di Biostrutture e Bioimmagini, CNR, via Mezzocannone 16, 80134, Napoli, Italy.,Second University of Naples, via Vivaldi 43, 81100, Caserta, Italy
| | - Menotti Ruvo
- Istituto di Biostrutture e Bioimmagini, CNR, via Mezzocannone 16, 80134, Napoli, Italy
| | - Marcelo Dias-Baruffi
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. Café S/N, CEP, 14040-903, Ribeirão Preto, São Paulo, Brazil
| | - Ivone Carvalho
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. Café S/N, CEP, 14040-903, Ribeirão Preto, São Paulo, Brazil
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12
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Pett C, Cai H, Liu J, Palitzsch B, Schorlemer M, Hartmann S, Stergiou N, Lu M, Kunz H, Schmitt E, Westerlind U. Microarray Analysis of Antibodies Induced with Synthetic Antitumor Vaccines: Specificity against Diverse Mucin Core Structures. Chemistry 2017; 23:3875-3884. [PMID: 27957769 DOI: 10.1002/chem.201603921] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Indexed: 01/08/2023]
Abstract
Glycoprotein research is pivotal for vaccine development and biomarker discovery. Many successful methodologies for reliably increasing the antigenicity toward tumor-associated glycopeptide structures have been reported. Deeper insights into the quality and specificity of the raised polyclonal, humoral reactions are often not addressed, despite the fact that an immunological memory, which produces antibodies with cross-reactivity to epitopes exposed on healthy cells, may cause autoimmune diseases. In the current work, three MUC1 antitumor vaccine candidates conjugated with different immune stimulants are evaluated immunologically. For assessment of the influence of the immune stimulant on antibody recognition, a comprehensive library of mucin 1 glycopeptides (>100 entries) is synthesized and employed in antibody microarray profiling; these range from small tumor-associated glycans (TN , STN , and T-antigen structures) to heavily extended O-glycan core structures (type-1 and type-2 elongated core 1-3 tri-, tetra-, and hexasaccharides) glycosylated in variable density at the five different sites of the MUC1 tandem repeat. This is one of the most extensive glycopeptide libraries ever made through total synthesis. On tumor cells, the core 2 β-1,6-N-acetylglucosaminyltransferase-1 (C2GlcNAcT-1) is down-regulated, resulting in lower amounts of the branched core 2 structures, which favor formation of linear core 1 or core 3 structures, and in particular, truncated tumor-associated antigen structures. The core 2 structures are commonly found on healthy cells and the elucidation of antibody cross-reactivity to such epitopes may predict the tumor-selectivity and safety of synthetic vaccines. With the extended mucin core structures in hand, antibody cross-reactivity toward the branched core 2 glycopeptide epitopes is explored. It is observed that the induced antibodies recognize MUC1 peptides with very high glycosylation site specificity. The nature of the antibody response is characteristically different for antibodies directed to glycosylation sites in either the immune-dominant PDTR or the GSTA domain. All antibody sera show high reactivity to the tumor-associated saccharide structures on MUC1. Extensive glycosylation with branched core 2 structures, typically found on healthy cells, abolishes antibody recognition of the antisera and suggests that all vaccine conjugates preferentially induce a tumor-specific humoral immune response.
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Affiliation(s)
- Christian Pett
- Gesellschaft zur Förderung der Analytischen Wissenschaften e.V. ISAS-Leibniz Institute for Analytical Sciences, Otto-Hahn-Str. 6b, 44227, Dortmund, Germany
| | - Hui Cai
- Gesellschaft zur Förderung der Analytischen Wissenschaften e.V. ISAS-Leibniz Institute for Analytical Sciences, Otto-Hahn-Str. 6b, 44227, Dortmund, Germany
| | - Jia Liu
- Institute for Virology, University Hospital of Essen, University of Duisburg-Essen, Essen, Germany
| | - Björn Palitzsch
- Institute of Organic Chemistry, Johannes Gutenberg, University of Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Manuel Schorlemer
- Gesellschaft zur Förderung der Analytischen Wissenschaften e.V. ISAS-Leibniz Institute for Analytical Sciences, Otto-Hahn-Str. 6b, 44227, Dortmund, Germany
| | - Sebastian Hartmann
- Institute of Organic Chemistry, Johannes Gutenberg, University of Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Natascha Stergiou
- University Medical Center, Institute of Immunology, Johannes Gutenberg University of Mainz, Langenbeckstr. 1, Geb. 708, 55101, Mainz, Germany
| | - Mengji Lu
- Institute for Virology, University Hospital of Essen, University of Duisburg-Essen, Essen, Germany
| | - Horst Kunz
- Institute of Organic Chemistry, Johannes Gutenberg, University of Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Edgar Schmitt
- University Medical Center, Institute of Immunology, Johannes Gutenberg University of Mainz, Langenbeckstr. 1, Geb. 708, 55101, Mainz, Germany
| | - Ulrika Westerlind
- Gesellschaft zur Förderung der Analytischen Wissenschaften e.V. ISAS-Leibniz Institute for Analytical Sciences, Otto-Hahn-Str. 6b, 44227, Dortmund, Germany
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13
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Martínez-Sáez N, Supekar NT, Wolfert MA, Bermejo IA, Hurtado-Guerrero R, Asensio JL, Jiménez-Barbero J, Busto JH, Avenoza A, Boons GJ, Peregrina JM, Corzana F. Mucin architecture behind the immune response: design, evaluation and conformational analysis of an antitumor vaccine derived from an unnatural MUC1 fragment. Chem Sci 2016; 7:2294-2301. [PMID: 29910919 PMCID: PMC5977504 DOI: 10.1039/c5sc04039f] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 12/06/2015] [Indexed: 02/01/2023] Open
Abstract
A tripartite cancer vaccine candidate, containing a quaternary amino acid (α-methylserine) in the most immunogenic domain of MUC1, has been synthesized and examined for antigenic properties in transgenic mice. The vaccine which is glycosylated with GalNAc at the unnatural amino acid, was capable of eliciting potent antibody responses recognizing both glycosylated and unglycosylated tumour-associated MUC1 peptides and native MUC1 antigen present on cancer cells. The peptide backbone of the novel vaccine presents the bioactive conformation in solution and is more resistant to enzymatic degradation than the natural counter part. In spite of these features, the immune response elicited by the unnatural vaccine was not improved compared to a vaccine candidate containing natural threonine. These observations were rationalized by conformational studies, indicating that the presentation and dynamics of the sugar moiety displayed by the MUC1 derivative play a critical role in immune recognition. It is clear that engineered MUC1-based vaccines bearing unnatural amino acids have to be able to emulate the conformational properties of the glycosidic linkage between the GalNAc and the threonine residues. The results described here will be helpful to the rational design of efficacious cancer vaccines.
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Affiliation(s)
- Nuria Martínez-Sáez
- Departamento de Química , Universidad de La Rioja , Centro de Investigación en Síntesis Química , Madre de Dios 53 , 26006 Logroño , Spain . ;
| | - Nitin T Supekar
- Complex Carbohydrate Research Center , University of Georgia , 315 Riverbend Road , Athens , Georgia 30602 , USA .
| | - Margreet A Wolfert
- Complex Carbohydrate Research Center , University of Georgia , 315 Riverbend Road , Athens , Georgia 30602 , USA .
| | - Iris A Bermejo
- Departamento de Química , Universidad de La Rioja , Centro de Investigación en Síntesis Química , Madre de Dios 53 , 26006 Logroño , Spain . ;
| | - Ramón Hurtado-Guerrero
- BIFI , University of Zaragoza , BIFI-IQFR (CSIC) Joint Unit , Mariano Esquillor s/n , Campus Rio Ebro , Edificio I+D , Zaragoza , Spain
- Fundación ARAID , 50018 , Zaragoza , Spain
| | - Juan L Asensio
- Instituto de Química Orgánica General , IQOG-CSIC , Juan de la Cierva 3 , 28006 Madrid , Spain
| | - Jesús Jiménez-Barbero
- Structural Biology Unit , CIC bioGUNE , Parque Tecnológico de Bizkaia Building 801A , 48160 Derio , Spain
- IKERBASQUE , Basque Foundation for Science , 48011 Bilbao , Spain
- Department of Chemical and Physical Biology , Centro de Investigaciones Biológicas , CSIC , Ramiro de Maeztu 9 , 28040 Madrid , Spain
| | - Jesús H Busto
- Departamento de Química , Universidad de La Rioja , Centro de Investigación en Síntesis Química , Madre de Dios 53 , 26006 Logroño , Spain . ;
| | - Alberto Avenoza
- Departamento de Química , Universidad de La Rioja , Centro de Investigación en Síntesis Química , Madre de Dios 53 , 26006 Logroño , Spain . ;
| | - Geert-Jan Boons
- Complex Carbohydrate Research Center , University of Georgia , 315 Riverbend Road , Athens , Georgia 30602 , USA .
| | - Jesús M Peregrina
- Departamento de Química , Universidad de La Rioja , Centro de Investigación en Síntesis Química , Madre de Dios 53 , 26006 Logroño , Spain . ;
| | - Francisco Corzana
- Departamento de Química , Universidad de La Rioja , Centro de Investigación en Síntesis Química , Madre de Dios 53 , 26006 Logroño , Spain . ;
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14
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Apostolopoulos V, Stojanovska L, Gargosky SE. MUC1 (CD227): a multi-tasked molecule. Cell Mol Life Sci 2015; 72:4475-500. [PMID: 26294353 PMCID: PMC11113675 DOI: 10.1007/s00018-015-2014-z] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 07/23/2015] [Accepted: 08/06/2015] [Indexed: 12/16/2022]
Abstract
Mucin 1 (MUC1 [CD227]) is a high-molecular weight (>400 kDa), type I membrane-tethered glycoprotein that is expressed on epithelial cells and extends far above the glycocalyx. MUC1 is overexpressed and aberrantly glycosylated in adenocarcinomas and in hematological malignancies. As a result, MUC1 has been a target for tumor immunotherapeutic studies in mice and in humans. MUC1 has been shown to have anti-adhesive and immunosuppressive properties, protects against infections, and is involved in the oncogenic process as well as in cell signaling. In addition, MUC1 plays a key role in the reproductive tract, in the immune system (affecting dendritic cells, monocytes, T cells, and B cells), and in chronic inflammatory diseases. Evidence for all of these roles for MUC1 is discussed herein and demonstrates that MUC1 is truly a multitasked molecule.
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Affiliation(s)
- Vasso Apostolopoulos
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, VIC, Australia.
| | - Lily Stojanovska
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, VIC, Australia
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15
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Martínez-Sáez N, Castro-López J, Valero-González J, Madariaga D, Compañón I, Somovilla VJ, Salvadó M, Asensio JL, Jiménez-Barbero J, Avenoza A, Busto JH, Bernardes GJL, Peregrina JM, Hurtado-Guerrero R, Corzana F. Deciphering the Non-Equivalence of Serine and Threonine O-Glycosylation Points: Implications for Molecular Recognition of the Tn Antigen by an anti-MUC1 Antibody. Angew Chem Int Ed Engl 2015; 54:9830-4. [PMID: 26118689 PMCID: PMC4552995 DOI: 10.1002/anie.201502813] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 05/06/2015] [Indexed: 11/11/2022]
Abstract
The structural features of MUC1-like glycopeptides bearing the Tn antigen (α-O-GalNAc-Ser/Thr) in complex with an anti MUC-1 antibody are reported at atomic resolution. For the α-O-GalNAc-Ser derivative, the glycosidic linkage adopts a high-energy conformation, barely populated in the free state. This unusual structure (also observed in an α-S-GalNAc-Cys mimic) is stabilized by hydrogen bonds between the peptidic fragment and the sugar. The selection of a particular peptide structure by the antibody is thus propagated to the carbohydrate through carbohydrate/peptide contacts, which force a change in the orientation of the sugar moiety. This seems to be unfeasible in the α-O-GalNAc-Thr glycopeptide owing to the more limited flexibility of the side chain imposed by the methyl group. Our data demonstrate the non-equivalence of Ser and Thr O-glycosylation points in molecular recognition processes. These features provide insight into the occurrence in nature of the APDTRP epitope for anti-MUC1 antibodies.
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Affiliation(s)
- Nuria Martínez-Sáez
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006 Logroño (Spain).,Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (UK)
| | - Jorge Castro-López
- Institute of Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, BIFI-IQFR (CSIC) Joint Unit, Edificio I+D, 50018 Zaragoza (Spain).,Fundación ARAID, Edificio Pignatelli 36, Zaragoza (Spain)
| | - Jessika Valero-González
- Institute of Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, BIFI-IQFR (CSIC) Joint Unit, Edificio I+D, 50018 Zaragoza (Spain).,Fundación ARAID, Edificio Pignatelli 36, Zaragoza (Spain)
| | - David Madariaga
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006 Logroño (Spain)
| | - Ismael Compañón
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006 Logroño (Spain)
| | - Víctor J Somovilla
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006 Logroño (Spain).,Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (UK)
| | - Míriam Salvadó
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (UK).,Departament de Química Analítica i Química Orgànica, Universitat Rovira i Virgili, C/Marcellí Domingo s/n, 43007 Tarragona (Spain)
| | - Juan L Asensio
- Instituto de Química Orgánica General, IQOG-CSIC, Juan de la Cierva 3, 28006 Madrid (Spain)
| | - Jesús Jiménez-Barbero
- Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia Building 801 A, 48160 Derio (Spain).,IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain).,Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid (Spain)
| | - Alberto Avenoza
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006 Logroño (Spain)
| | - Jesús H Busto
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006 Logroño (Spain)
| | - Gonçalo J L Bernardes
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (UK).,Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa (Portugal)
| | - Jesús M Peregrina
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006 Logroño (Spain).
| | - Ramón Hurtado-Guerrero
- Institute of Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, BIFI-IQFR (CSIC) Joint Unit, Edificio I+D, 50018 Zaragoza (Spain). .,Fundación ARAID, Edificio Pignatelli 36, Zaragoza (Spain).
| | - Francisco Corzana
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006 Logroño (Spain).
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16
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Martínez-Sáez N, Castro-López J, Valero-González J, Madariaga D, Compañón I, Somovilla VJ, Salvadó M, Asensio JL, Jiménez-Barbero J, Avenoza A, Busto JH, Bernardes GJL, Peregrina JM, Hurtado-Guerrero R, Corzana F. Deciphering the Non-Equivalence of Serine and ThreonineO-Glycosylation Points: Implications for Molecular Recognition of the Tn Antigen by an anti-MUC1 Antibody. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201502813] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Galibert M, Piller V, Piller F, Aucagne V, Delmas AF. Combining triazole ligation and enzymatic glycosylation on solid phase simplifies the synthesis of very long glycoprotein analogues. Chem Sci 2015; 6:3617-3623. [PMID: 30155000 PMCID: PMC6085731 DOI: 10.1039/c5sc00773a] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 04/12/2015] [Indexed: 01/01/2023] Open
Abstract
The solid-phase chemical assembly of a protein through iterative chemoselective ligation of unprotected peptide segments can be followed with chemical and/or enzymatic transformations of the resulting immobilized protein, the latter steps thus benefitting from the advantages provided by the solid support. We demonstrate here the usefulness of this strategy for the chemo-enzymatic synthesis of glycoprotein analogues. A linker was specifically designed for application to the synthesis of O-glycoproteins: this new linker is readily cleaved under mild aqueous conditions compatible with very sensitive glycosidic bonds, but is remarkably stable under a wide range of chemical and biochemical conditions. It was utilized for solid-supported N-to-C peptidomimetic triazole ligation followed by enzymatic glycosylation, ultimately leading to a very large MUC1-derived glycoprotein containing 160 amino acid residues, 24 α-GalNAc moieties linked to Ser and Thr, and 3 triazoles as peptide bond mimetics.
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Affiliation(s)
- Mathieu Galibert
- Centre de Biophysique Moléculaire , CNRS UPR 4301 , Rue Charles Sadron , 45071 Orléans Cedex 2 , France .
| | - Véronique Piller
- Centre de Biophysique Moléculaire , CNRS UPR 4301 , Rue Charles Sadron , 45071 Orléans Cedex 2 , France .
| | - Friedrich Piller
- Centre de Biophysique Moléculaire , CNRS UPR 4301 , Rue Charles Sadron , 45071 Orléans Cedex 2 , France .
| | - Vincent Aucagne
- Centre de Biophysique Moléculaire , CNRS UPR 4301 , Rue Charles Sadron , 45071 Orléans Cedex 2 , France .
| | - Agnès F Delmas
- Centre de Biophysique Moléculaire , CNRS UPR 4301 , Rue Charles Sadron , 45071 Orléans Cedex 2 , France .
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18
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Madariaga D, Martínez-Sáez N, Somovilla VJ, Coelho H, Valero-González J, Castro-López J, Asensio JL, Jiménez-Barbero J, Busto JH, Avenoza A, Marcelo F, Hurtado-Guerrero R, Corzana F, Peregrina JM. Detection of tumor-associated glycopeptides by lectins: the peptide context modulates carbohydrate recognition. ACS Chem Biol 2015; 10:747-56. [PMID: 25457745 DOI: 10.1021/cb500855x] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Tn antigen (α-O-GalNAc-Ser/Thr) is a convenient cancer biomarker that is recognized by antibodies and lectins. This work yields remarkable results for two plant lectins in terms of epitope recognition and reveals that these receptors show higher affinity for Tn antigen when it is incorporated in the Pro-Asp-Thr-Arg (PDTR) peptide region of mucin MUC1. In contrast, a significant affinity loss is observed when Tn antigen is located in the Ala-His-Gly-Val-Thr-Ser-Ala (AHGVTSA) or Ala-Pro-Gly-Ser-Thr-Ala-Pro (APGSTAP) fragments. Our data indicate that the charged residues, Arg and Asp, present in the PDTR sequence establish noteworthy fundamental interactions with the lectin surface as well as fix the conformation of the peptide backbone, favoring the presentation of the sugar moiety toward the lectin. These results may help to better understand glycopeptide-lectin interactions and may contribute to engineer new binding sites, allowing novel glycosensors for Tn antigen detection to be designed.
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Affiliation(s)
- David Madariaga
- Centro de Investigación
en Síntesis Química, Departamento de Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Nuria Martínez-Sáez
- Centro de Investigación
en Síntesis Química, Departamento de Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Víctor J. Somovilla
- Centro de Investigación
en Síntesis Química, Departamento de Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Helena Coelho
- Centro de Investigación
en Síntesis Química, Departamento de Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Jessika Valero-González
- Centro de Investigación
en Síntesis Química, Departamento de Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Jorge Castro-López
- Centro de Investigación
en Síntesis Química, Departamento de Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Juan L. Asensio
- Centro de Investigación
en Síntesis Química, Departamento de Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Jesús Jiménez-Barbero
- Centro de Investigación
en Síntesis Química, Departamento de Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Jesús H. Busto
- Centro de Investigación
en Síntesis Química, Departamento de Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Alberto Avenoza
- Centro de Investigación
en Síntesis Química, Departamento de Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Filipa Marcelo
- Centro de Investigación
en Síntesis Química, Departamento de Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Ramón Hurtado-Guerrero
- Centro de Investigación
en Síntesis Química, Departamento de Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Francisco Corzana
- Centro de Investigación
en Síntesis Química, Departamento de Química, Universidad de La Rioja, E-26006 Logroño, Spain
| | - Jesús M. Peregrina
- Centro de Investigación
en Síntesis Química, Departamento de Química, Universidad de La Rioja, E-26006 Logroño, Spain
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19
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Haddon L, Hugh J. MUC1-mediated motility in breast cancer: a review highlighting the role of the MUC1/ICAM-1/Src signaling triad. Clin Exp Metastasis 2015; 32:393-403. [PMID: 25759211 DOI: 10.1007/s10585-015-9711-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 03/03/2015] [Indexed: 12/16/2022]
Abstract
Breast cancer is the most common cancer in women with the leading cause of death being metastasis, the spread of cancer to distant organs. For those patients with high-risk estrogen receptor positive (ER+) breast cancer, an increased expression of the glycoprotein MUC1 is associated with resistance to anti-hormonal therapy, metastasis and death. Tumor cells may use MUC1 to metastasize by exploiting the vascular adhesion pathways used by leukocytes during the inflammatory response. MUC1 is a type 1 transmembrane protein whose cytoplasmic tail acts as a scaffold for several signaling pathways including the non-receptor kinase Src, a signaling molecule involved in cell differentiation, proliferation, adhesion and motility. This review will highlight our current knowledge of how MUC1/ICAM-1 binding can lead to the recruitment and activation of Src and propose a novel role for lipid raft microdomains in this promigratory signaling. Improved understanding of the mechanism of metastases and the underlying signaling cascade is a prerequisite to the discovery of therapeutic targets to prevent metastasis and death in ER+ breast cancer patients.
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Affiliation(s)
- Lacey Haddon
- Department of Laboratory of Medicine and Pathology, University of Alberta, Edmonton, AB, Canada
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20
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Dhar J, Chakrabarti P, Saini H, Raghava GPS, Kishore R. ω-Turn: a novel β-turn mimic in globular proteins stabilized by main-chain to side-chain C−H···O interaction. Proteins 2014; 83:203-14. [PMID: 25388861 DOI: 10.1002/prot.24720] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 10/28/2014] [Accepted: 11/03/2014] [Indexed: 11/10/2022]
Abstract
Mimicry of structural motifs is a common feature in proteins. The 10-membered hydrogen-bonded ring involving the main-chain C − O in a β-turn can be formed using a side-chain carbonyl group leading to Asx-turn. We show that the N − H component of hydrogen bond can be replaced by a C(γ) -H group in the side chain, culminating in a nonconventional C − H···O interaction. Because of its shape this β-turn mimic is designated as ω-turn, which is found to occur ∼ three times per 100 residues. Three residues (i to i + 2) constitute the turn with the C − H···O interaction occurring between the terminal residues, constraining the torsion angles ϕi + 1, ψi + 1, ϕi + 2 and χ'1(i + 2) (using the interacting C(γ) atom). Based on these angles there are two types of ω-turns, each of which can be further divided into two groups. C(β) -branched side-chains, and Met and Gln have high propensities to occur at i + 2; for the last two residues the carbonyl oxygen may participate in an additional interaction involving the S and amino group, respectively. With Cys occupying the i + 1 position, such turns are found in the metal-binding sites. N-linked glycosylation occurs at the consensus pattern Asn-Xaa-Ser/Thr; with Thr at i + 2, the sequence can adopt the secondary structure of a ω-turn, which may be the recognition site for protein modification. Location between two β-strands is the most common occurrence in protein tertiary structure, and being generally exposed ω-turn may constitute the antigenic determinant site. It is a stable scaffold and may be used in protein engineering and peptide design.
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Affiliation(s)
- Jesmita Dhar
- Bioinformatics Centre, Bose Institute, Kolkata, West Bengal, 700 054, India
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21
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Madariaga D, Martínez-Sáez N, Somovilla VJ, García-García L, Berbis MÁ, Valero-Gónzalez J, Martín-Santamaría S, Hurtado-Guerrero R, Asensio JL, Jiménez-Barbero J, Avenoza A, Busto JH, Corzana F, Peregrina JM. Serine versus Threonine Glycosylation with α-O-GalNAc: Unexpected Selectivity in Their Molecular Recognition with Lectins. Chemistry 2014; 20:12616-27. [DOI: 10.1002/chem.201403700] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Indexed: 12/17/2022]
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22
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Marcos-Silva L, Narimatsu Y, Halim A, Campos D, Yang Z, Tarp MA, Pereira PJB, Mandel U, Bennett EP, Vakhrushev SY, Levery SB, David L, Clausen H. Characterization of binding epitopes of CA125 monoclonal antibodies. J Proteome Res 2014; 13:3349-59. [PMID: 24850311 DOI: 10.1021/pr500215g] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The most used cancer serum biomarker is the CA125 immunoassay for ovarian cancer that detects the mucin glycoprotein MUC16. Several monoclonal antibodies (mAbs) including OC125 and M11 are used in CA125 assays. However, despite considerable efforts, our knowledge of the molecular characteristics of the recognized epitopes and the role played by glycosylation has remained elusive. Here a comprehensive set of recombinant MUC16 tandem repeats (TRs) expressed in glycoengineered mammalian cells and E. coli, together with overlapping peptides, was used to probe antigen-binding epitopes. We present a complete analysis of N- and O-glycosylation sites of a MUC16 TR expressed in CHO cells and demonstrate that neither N- nor O-glycosylation appear to substantially influence binding of OC125 and M11 mAbs. A series of successive N- and C-terminal truncations of a MUC16 TR construct expressed in E. coli narrowed down the epitopes for OC125 and M11 to a segment containing parts of two consecutive SEA domains with a linker. Thus, a complete SEA domain is not required. These findings suggest that binding epitopes of mAbs OC125 and M11 are dependent on conformation but not on glycosylation. The availability of recombinant TR constructs with and without aberrant glycosylation now opens the way for vaccine studies.
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Affiliation(s)
- Lara Marcos-Silva
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen , Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
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23
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Barchi JJ. Mucin-Type Glycopeptide Structure in Solution: Past, Present, and Future. Biopolymers 2013; 99:713-23. [DOI: 10.1002/bip.22313] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Accepted: 06/05/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Joseph J. Barchi
- Chemical Biology Laboratory; Center for Cancer Research, National Cancer Institute at Frederick; Frederick; MD; 21702
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24
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Shukla RT, Sasidhar YU. Energetics of β-turn formation in a mutant peptide YPGDV from influenza hemagglutinin: an MD simulation study. Phys Chem Chem Phys 2013; 15:18571-83. [DOI: 10.1039/c3cp52166d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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25
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Mallajosyula SS, MacKerell AD. Influence of solvent and intramolecular hydrogen bonding on the conformational properties of o-linked glycopeptides. J Phys Chem B 2011; 115:11215-29. [PMID: 21823626 PMCID: PMC3179525 DOI: 10.1021/jp203695t] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A detailed investigation of the conformational properties of all the biologically relevant O-glycosidic linkages using the Hamiltonian replica exchange (HREX) simulation methodology and the recently developed CHARMM carbohydrate force field parameters is presented. Fourteen biologically relevant O-linkages between the five sugars N-acetylgalactosamine (GalNAc), N-acetylglucosamine (GlcNAc), D-glucose (Glc), D-mannose (Man), and L-fucose (Fuc) and the amino acids serine and threonine were studied. The force field was tested by comparing the simulation results of the model glycopeptides to various NMR (3)J coupling constants, NOE distances, and data from molecular dynamics with time-averaged restraints (tar-MD). The results show the force field to be in overall agreement with experimental and previous tar-MD simulations, although some small limitations are identified. An in-depth hydrogen bond and bridging water analysis revealed an interplay of hydrogen bonding and bridge water interactions influencing the geometry of the underlying peptide backbone, with the O-linkages favoring extended β-sheet and polyproline type II (PPII) conformations over the compact α(R)-helical conformation. The newly developed parameters were also able to identify hydrogen bonding and water mediated interactions between O-linked sugars and proteins. These results indicate that the newly developed parameters in tandem with HREX conformational sampling provide the means to study glycoproteins in the absence of targeted NMR restraint data.
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Affiliation(s)
- Sairam S. Mallajosyula
- Department of Pharmaceutical Sciences, 20 Penn Street HSF II, University of Maryland, Baltimore, Maryland 21201
| | - Alexander D. MacKerell
- Department of Pharmaceutical Sciences, 20 Penn Street HSF II, University of Maryland, Baltimore, Maryland 21201
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26
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Singh AK, Rath SK, Misra K. Identification of epitopes in Indian human papilloma virus 16 E6: a bioinformatics approach. J Virol Methods 2011; 177:26-30. [PMID: 21699918 DOI: 10.1016/j.jviromet.2011.06.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 05/31/2011] [Accepted: 06/07/2011] [Indexed: 11/16/2022]
Abstract
HPV-16 is reported as the cause of cervical and other related carcinomas. The early expressed protein E6 in cancer cells is found to be the target for immune therapeutic methods. The sequence of HPV-16 E6 (Accession No: ABK32509) from NCBI databank has been taken for this study. Hydrophilicity, flexibility, accessibility, turns, exposed surface, polarity and antigenic propensity scales were used for the B cell epitope prediction. MHC Class I and Class II alleles for the accession were predicted by the MHCPred 2.0 Program. The epitope sequences were also found out. Computer-based prediction program results show, A0203 and DRB0101 lower IC50 than other alleles. The best peptide binding affinity was 21HLCTELQTT30 of A0203 allele. In DRB0101 allele the peptide found was 39YCKQQLLRR48. Different structural features of the protein have also been predicted including glycosylation, kinase C phosphorylation, casein kinase II phosphorylation and N-myristylation sites. These computational prediction programs show four glycosylation, five kinase C phosphorylation, two casein kinase II phosphorylation, zero N-myristylation sites and seven disulphide sites. Development and approval of new vaccines are the keys for control of cancer. Epitopes and other structural features of protein prediction could be the best source of information and can help in molecular and medical studies of viral infection and development of HPV associated cancer drugs.
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Affiliation(s)
- Ajay Kumar Singh
- Centre for Biomedical Magnetic Research, SGPGI Campus, Lucknow, India.
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27
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Corzana F, Busto JH, Marcelo F, García de Luis M, Asensio JL, Martín‐Santamaría S, Jiménez‐Barbero J, Avenoza A, Peregrina JM. Engineering
O
‐Glycosylation Points in Non‐extended Peptides: Implications for the Molecular Recognition of Short Tumor‐Associated Glycopeptides. Chemistry 2011; 17:3105-10. [DOI: 10.1002/chem.201003124] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Indexed: 12/15/2022]
Affiliation(s)
- Francisco Corzana
- Departmento de Química, Universidad de La Rioja, Madre de Dios, 51, 26006 Logroño (Spain), Fax: (+34) 941‐299‐621
| | - Jesús H. Busto
- Departmento de Química, Universidad de La Rioja, Madre de Dios, 51, 26006 Logroño (Spain), Fax: (+34) 941‐299‐621
| | - Filipa Marcelo
- Centro de Investigaciones Biológicas (CSIC), Madrid (Spain)
| | - Marisa García de Luis
- Departmento de Química, Universidad de La Rioja, Madre de Dios, 51, 26006 Logroño (Spain), Fax: (+34) 941‐299‐621
| | | | | | | | - Alberto Avenoza
- Departmento de Química, Universidad de La Rioja, Madre de Dios, 51, 26006 Logroño (Spain), Fax: (+34) 941‐299‐621
| | - Jesús M. Peregrina
- Departmento de Química, Universidad de La Rioja, Madre de Dios, 51, 26006 Logroño (Spain), Fax: (+34) 941‐299‐621
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28
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Ohyabu N, Hinou H, Matsushita T, Izumi R, Shimizu H, Kawamoto K, Numata Y, Togame H, Takemoto H, Kondo H, Nishimura SI. An essential epitope of anti-MUC1 monoclonal antibody KL-6 revealed by focused glycopeptide library. J Am Chem Soc 2010; 131:17102-9. [PMID: 19899793 DOI: 10.1021/ja903361f] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Human serum Krebs von den Lungen-6 (KL-6) antigen, a high-molecular-weight glycoprotein classified as a polymorphic epithelial mucin (MUC1), is a biomarker of diseases such as interstitial pneumonia, lung adenocarcinoma, breast cancer, colorectal adenocarcinoma, and hepatocellular carcinoma. Anti-KL-6 monoclonal antibody (anti-KL-6 MAb) is therefore a potential diagnostic and therapeutic reagent. Although glycosylation at Thr/Ser residues of the tandem-repeating MUC1 peptides appears to determine the disease-associated antigenic structures of KL-6, an essential epitope structure recognized by anti-KL-6 MAb remains unclear. In the present study, a novel compound library of synthetic MUC1 glycopeptides allowed the first rapid and precise evaluation of the specific epitope structure of anti-KL-6 MAb by combined use of a tailored glycopeptides library and common ELISA protocol. We demonstrated that the minimal antigenic structure, an essential epitope, recognized by anti-KL-6 MAb is a heptapeptide sequence Pro-Asp-Thr-Arg-Pro-Ala-Pro (PDTRPAP), in which the Thr residue is modified by Neu5Ac alpha2,3Gal beta1,3GalNAc alpha (2,3-sialyl T antigen, core 1-type O-glycan). Anti-KL-6 MAb did not bind with other tumor-relevant antigens, such as GalNAc alpha (Tn), Neu5Ac alpha2,6GalNAc alpha (STn), and Gal beta1,3GalNAc alpha (T), except for Neu5Ac alpha2,3Gal beta1,3(Neu5Ac alpha2,6)GalNAc alpha (2,3/2,6-disialyl T). However, anti-KL-6 MAb could not differentiate the above minimal antigenic glycopeptide from some core 2-based glycopeptides involving this crucial epitope structure and showed a similar binding affinity toward these compounds, indicating that branching at the O-6 position of GalNAc residue does not influence the interaction of anti-KL-6 MAb with some MUC1 glycoproteins involving an essential epitope. Actually, anti-KL-6 MAb reacts with 2,3/2,6-disialyl T having a 2,3-sialyl T component. This is why anti-KL-6 MAb often reacts with various kinds of tumor-derived MUC1 glycoproteins as well as a clinically important MUC1 glycoprotein biomarker of interstitial pneumonia, namely KL-6, originally discovered as a circulating pulmonary adenocarcinoma-associated antigen. In other words, combined use of anti-KL-6 MAb and some probes that can differentiate the sugars substituted at the O-6 position of the GalNAc residue in MUC1 glycopeptides including the PDTRPAP sequence might be a promising diagnostic protocol for individual disease-specific biomarkers. It was also revealed that glycosylation at neighboring Thr/Ser residues outside the immunodominant PDTRPAP motif strongly influences the interaction between anti-KL-6 MAb and MUC1 glycopeptides involving the identified epitope. Our novel strategy will greatly facilitate the processes for the identification of the tumor-specific and strong epitopes of various known anti-MUC1 MAbs and allow for their practical application in the generation of improved antibody immunotherapeutics, diagnostics, and MUC1-based cancer vaccines.
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Affiliation(s)
- Naoki Ohyabu
- Division of Advanced Chemical Biology, Graduate School of Advanced Life Science, Frontier Research Center for Post-Genome Science and Technology, Hokkaido University, N-21, W-11, Kita-ku, Sapporo 001-0021, Japan
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29
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Sendra VG, Zlocowski N, Ditamo Y, Copioli S, Tarp MP, Bennett EP, Clausen H, Roth GA, Nores GA, Irazoqui FJ. Glycan bioengineering in immunogen design for tumor T antigen immunotargeting. Mol Immunol 2009; 46:3445-53. [DOI: 10.1016/j.molimm.2009.08.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Accepted: 08/11/2009] [Indexed: 02/04/2023]
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30
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Fernández-Tejada A, Corzana F, Busto JH, Jiménez-Osés G, Jiménez-Barbero J, Avenoza A, Peregrina JM. Insights into the geometrical features underlying beta-O-GlcNAc glycosylation: water pockets drastically modulate the interactions between the carbohydrate and the peptide backbone. Chemistry 2009; 15:7297-301. [PMID: 19544521 DOI: 10.1002/chem.200901204] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Alberto Fernández-Tejada
- Departamento de Química, Universidad de La Rioja, UA-CSIC. Madre de Dios 51, 26006 Logroño, La Rioja, Spain
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31
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Spiriti J, Bogani F, van der Vaart A, Ghirlanda G. Modulation of protein stability by O-glycosylation in a designed Gc-MAF analog. Biophys Chem 2008; 134:157-67. [PMID: 18329161 DOI: 10.1016/j.bpc.2008.02.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Revised: 01/28/2008] [Accepted: 02/08/2008] [Indexed: 11/24/2022]
Abstract
The post-translational modification of proteins by the covalent attachment of carbohydrates to specific side chains, or glycosylation, is emerging as a crucial process in modulating the function of proteins. In particular, the dynamic processing of the oligosaccharide can correlate with a change in function. For example, a potent macrophage-activating factor, Gc-MAF, is obtained from serum vitamin D binding protein (VDBP) by stepwise processing of the oligosaccharide attached to Thr 420 to the core alpha-GalNAc moiety. In previous work we designed a miniprotein analog of Gc-MAF, MM1, by grafting the glycosylated loop of Gc-MAF on a stable scaffold. GalNAc-MM1 showed native-like activity on macrophages (Bogani 2006, J. Am. Chem. Soc. 128 7142-43). Here, we present data on the thermodynamic stability and conformational dynamics of the mono- and diglycosylated forms. We observed an unusual trend: each glycosylation event destabilized the protein by about 1 kcal/mol. This effect is matched by an increase in the mobility of the glycosylated forms, as evaluated by molecular dynamics simulations. An analysis of the solvent-accessible surface area shows that glycosylation causes the three-helix bundle to adopt conformations in which the hydrophobic residues are more solvent exposed. The number of hydrophobic contacts is also affected. These two factors, which are ultimately explained with a change in occupancy for conformers of specific side chains, may contribute to the observed destabilization.
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Affiliation(s)
- Justin Spiriti
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, United States
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32
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Sumiyoshi M, Ricciuto J, Tisdale A, Gipson IK, Mantelli F, Argüeso P. Antiadhesive character of mucin O-glycans at the apical surface of corneal epithelial cells. Invest Ophthalmol Vis Sci 2008; 49:197-203. [PMID: 18172093 DOI: 10.1167/iovs.07-1038] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Prolonged contact of opposite mucosal surfaces, which occurs on the ocular surface, oral cavity, reproductive tract, and gut, requires a specialized apical cell surface that prevents adhesion. The purpose of this study was to evaluate the contribution of mucin O-glycans to the antiadhesive character of human corneal-limbal epithelial (HCLE) cells. METHODS Mucin O-glycan biosynthesis in HCLE cells was disrupted by metabolic interference with benzyl-alpha-GalNAc. The cell surface mucin MUC16 and its carbohydrate epitope H185 were detected by immunofluorescence and Western blot. HCLE cell surface features were assessed by field emission scanning electron microscopy. Cell-cell adhesion assays were performed under static conditions and in a parallel plate laminar flow chamber. RESULTS Benzyl-alpha-GalNAc disrupted the biosynthesis of O-glycans without affecting apomucin biosynthesis or cell surface morphology. Static adhesion assays showed that the apical surface of differentiated HCLE cells expressing MUC16 and H185 was more antiadhesive than undifferentiated HCLE cells, which lacked MUC16. Abrogation of mucin O-glycosylation in differentiated cultures with benzyl-alpha-GalNAc resulted in increased adhesion of applied corneal epithelial cells and corneal fibroblasts. The antiadhesive effect of mucin O-glycans was further demonstrated by fluorescence video microscopy in dynamic flow adhesion assays. Cationized ferritin labeling of the cell surface indicated that anionic repulsion did not contribute to the antiadhesive character of the apical surface. CONCLUSIONS These results indicate that epithelial O-glycans contribute to the antiadhesive properties of cell surface-associated mucins in corneal epithelial cells and suggest that alterations in mucin O-glycosylation are involved in the pathology of drying mucosal diseases (e.g., dry eye).
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Affiliation(s)
- Mika Sumiyoshi
- Schepens Eye Research Institute and the Department of Ophthalmology, Harvard Medical School, 20 Staniford Street, Boston, MA 02114, USA
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33
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Mátyus E, Blaskó K, Fidy J, Tieleman DP. Structure and dynamics of the antifungal molecules Syringotoxin-B and Syringopeptin-25A from molecular dynamics simulation. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2007; 37:495-502. [DOI: 10.1007/s00249-007-0242-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Revised: 11/15/2007] [Accepted: 11/16/2007] [Indexed: 11/24/2022]
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34
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Kurtenkov O, Klaamas K, Mensdorff-Pouilly S, Miljukhina L, Shljapnikova L, Chuzmarov V. Humoral immune response to MUC1 and to the Thomsen-Friedenreich (TF) glycotope in patients with gastric cancer: relation to survival. Acta Oncol 2007; 46:316-23. [PMID: 17450466 DOI: 10.1080/02841860601055441] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Humoral immune responses to the MUC1 peptide and to MUC1-related Thomsen-Friedenreich (TF) glycotope was investigated in patients with gastric cancer (n = 247), chronic gastroduodenal diseases (n = 199) and in healthy blood donors (n = 100). Data were correlated with disease type, stage of cancer, tumor morphology and survival. MUC1 IgG antibody levels were higher in patients with gastric cancer (p < 0.0001) than in healthy controls. Higher levels of anti-MUC1 IgG were also detected in patients with ulcer of the stomach (p = 0.015) and in atrophic gastritis (p = 0.027). Compared to blood donors, significantly lower levels of anti-TF IgG were found both in the cancer (p = 0.002) and in the benign group (p < 0.0001). At early stages of cancer a positive correlation (p < 0.0001) was found between MUC1 IgG and TF IgG antibody levels. High levels of TF IgG antibodies were significantly associated with a benefit in survival of gastric cancer patients (p = 0.003). A similar though weaker association was observed for patients with high levels of MUC1 IgG antibodies and locoregional disease (stage I-III) (p = 0.037). Thus IgG immune responses to MUC1 are increased in patients with gastric cancer. High levels of either TF IgG or MUC1 IgG antibodies may predict better outcome in surgically treated patients with gastric cancer.
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Affiliation(s)
- O Kurtenkov
- National Institute for Health Development, Hiiu 42, Tallinn 11619, Estonia.
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35
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Dziadek S, Griesinger C, Kunz H, Reinscheid UM. Synthesis and structural model of an alpha(2,6)-sialyl-t glycosylated MUC1 eicosapeptide under physiological conditions. Chemistry 2007; 12:4981-93. [PMID: 16642533 DOI: 10.1002/chem.200600144] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
To study the effect of O-glycosylation on the conformational propensities of a peptide backbone, a 20-residue peptide (GSTAPPAHGVTSAPDTRPAP) representing the full length tandem repeat sequence of the human mucin MUC1 and its analogue glycosylated with the (2,6)-sialyl-T antigen on Thr11, were prepared and investigated by NMR and molecular modeling. The peptides contain both the GVTSAP sequence, which is an effective substrate for GalNAc transferases, and the PDTRP fragment, a known epitope recognized by several anti-MUC1 monoclonal antibodies. It has been shown that glycosylation of threonine in the GVTSAP sequence is a prerequisite for subsequent glycosylation of the serine at GVTSAP. Furthermore, carbohydrates serve as additional epitopes for MUC1 antibodies. Investigation of the solution structure of the sialyl-T glycoeicosapeptide in a H(2)O/D(2)O mixture (9:1) under physiological conditions (25 degrees C and pH 6.5) revealed that the attachment of the saccharide side-chain affects the conformational equilibrium of the peptide backbone near the glycosylated Thr11 residue. For the GVTSA region, an extended, rod-like secondary structure was found by restrained molecular dynamics simulation. The APDTR region formed a turn structure which is more flexibly organized. Taken together, the joined sequence GVTSAPDTR represents the largest structural model of MUC1 derived glycopeptides analyzed so far.
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Affiliation(s)
- Sebastian Dziadek
- Institut für Organische Chemie der Universität Mainz, Duesbergweg 10-14, 55099 Mainz, Germany
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36
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Kuhn A, Kunz H. Vom Kohlenhydrat induzierte Peptidkonformation in Glycopeptiden aus der Erkennungsregion von LI-Cadherin. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200602494] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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37
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Kuhn A, Kunz H. Saccharide-Induced Peptide Conformation in Glycopeptides of the Recognition Region of LI-Cadherin. Angew Chem Int Ed Engl 2007; 46:454-8. [PMID: 17154199 DOI: 10.1002/anie.200602494] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Axel Kuhn
- Institut für Organische Chemie, Universität Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
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38
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Chen YX, Du JT, Zhou LX, Liu XH, Zhao YF, Nakanishi H, Li YM. Alternative O-GlcNAcylation/O-phosphorylation of Ser16 induce different conformational disturbances to the N terminus of murine estrogen receptor beta. ACTA ACUST UNITED AC 2006; 13:937-44. [PMID: 16984883 DOI: 10.1016/j.chembiol.2006.06.017] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2006] [Revised: 06/16/2006] [Accepted: 06/26/2006] [Indexed: 01/09/2023]
Abstract
Serine and threonine residues in many proteins can be modified by either phosphorylation or GlcNAcylation. To investigate the mechanism of O-GlcNAc and O-phosphate's reciprocal roles in modulating the degradation and activity of murine estrogen receptor beta (mER-beta), the conformational changes induced by O-GlcNAcylation and O-phosphorylation of Ser(16) in 17-mer model peptides corresponding to the N-terminal intrinsically disordered (ID) region of mER-beta were studied by NMR techniques, circular dichroism (CD), and molecular dynamics simulations. Our results suggest that O-phosphorylation discourages the turn formation in the S(15)STG(18) fragment. In contrast, O-GlcNAcylation promotes turn formation in this region. Thus, we postulate that the different changes of the local structure in the N-terminal S(15)STG(18) fragment of mER-beta caused by O-phosphate or O-GlcNAc modification might lead to the disturbances to the dynamic ensembles of the ID region of mER-beta, which is related to its modulatory activity.
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Affiliation(s)
- Yong-Xiang Chen
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
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Danielczyk A, Stahn R, Faulstich D, Löffler A, Märten A, Karsten U, Goletz S. PankoMab: a potent new generation anti-tumour MUC1 antibody. Cancer Immunol Immunother 2006; 55:1337-47. [PMID: 16485130 PMCID: PMC11029825 DOI: 10.1007/s00262-006-0135-9] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Accepted: 01/14/2006] [Indexed: 12/11/2022]
Abstract
Recently, we described a new carbohydrate-induced conformational tumour-epitope on mucin-1 (MUC1) with the potential for improvement of immunotherapies [29, 30]. PankoMab is a novel antibody, which binds specifically to this epitope and was designed to show the highest glycosylation dependency and the strongest additive binding effect when compared to other MUC1 antibodies. This enables PankoMab to differentiate between tumour MUC1 and non-tumour MUC1 epitopes. It has a high-affinity towards tumour cells (e.g. KD [M] of 0.9 and 3x10(-9 )towards NM-D4 and ZR75-1, respectively) and detects a very large number of binding sites (e.g. 1.0 and 2.4x10(6 )for NM-D4 and ZR75-1, respectively). PankoMab is rapidly internalised, and after toxin coupling is able to induce very effectively toxin-mediated antigen-specific tumour cell killing. PankoMab reveals a potent tumour-specific antibody-dependent cell cytotoxicity (ADCC). PankoMab is, therefore, distinguished by a combination of advantages compared to other MUC1 antibodies in clinical development, including higher tumour specificity, higher affinity, a higher number of binding sites, largely reduced binding to shed MUC1 from colon and pancreatic carcinoma patients, no binding to mononucleated cells from peripheral blood (except approximately 7% of activated T cells), stronger ADCC activity and rapid internalisation as required for toxin-mediated cell killing. This renders it a superior antibody for in vivo diagnostics and various immunotherapeutic approaches.
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Affiliation(s)
| | - Renate Stahn
- GLYCOTOPE GmbH, Berlin, Germany
- NEMOD Biotherapeutics GmbH & Co.KG, Berlin, Germany
| | | | | | - Angela Märten
- Department of Surgery, University of Heidelberg, Berlin, Germany
| | - Uwe Karsten
- GLYCOTOPE GmbH, Berlin, Germany
- Max Delbrück Centre for Molecular Medicine, Berlin, Germany
| | - Steffen Goletz
- GLYCOTOPE GmbH, Berlin, Germany
- NEMOD Biotherapeutics GmbH & Co.KG, Berlin, Germany
- Charité—Academic Medicine, Institute for Molecular Biology and Biochemistry, Humboldt University, Campus Benjamin Franklin, Berlin, Germany
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Sørensen AL, Reis CA, Tarp MA, Mandel U, Ramachandran K, Sankaranarayanan V, Schwientek T, Graham R, Taylor-Papadimitriou J, Hollingsworth MA, Burchell J, Clausen H. Chemoenzymatically synthesized multimeric Tn/STn MUC1 glycopeptides elicit cancer-specific anti-MUC1 antibody responses and override tolerance. Glycobiology 2005; 16:96-107. [PMID: 16207894 DOI: 10.1093/glycob/cwj044] [Citation(s) in RCA: 210] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The MUC1 mucin represents a prime target antigen for cancer immunotherapy because it is abundantly expressed and aberrantly glycosylated in carcinomas. Attempts to generate strong humoral immunity to MUC1 by immunization with peptides have generally failed partly because of tolerance. In this study, we have developed chemoenzymatic synthesis of extended MUC1 TR glycopeptides with cancer-associated O-glycosylation using a panel of recombinant human glycosyltransferases. MUC1 glycopeptides with different densities of Tn and STn glycoforms conjugated to KLH were used as immunogens to evaluate an optimal vaccine design. Glycopeptides with complete O-glycan occupancy (five sites per repeat) elicited the strongest antibody response reacting with MUC1 expressed in breast cancer cell lines in both Balb/c and MUC1.Tg mice. The elicited humoral immune response showed remarkable specificity for cancer cells suggesting that the glycopeptide design holds promise as a cancer vaccine. The elicited immune responses were directed to combined glycopeptide epitopes, and both peptide sequence and carbohydrate structures were important for the antigen. A MAb (5E5) with similar specificity as the elicited immune response was generated and shown to have the same remarkable cancer specificity. This antibody may hold promise in diagnostic and immunopreventive measures.
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Affiliation(s)
- Anne Louise Sørensen
- Department of Medical Biochemistry and Genetics, University of Copenhagen, Blegdamsvej 3, DK2200 Copenhagen, Denmark
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Irazoqui FJ, Sendra VG, Lardone RD, Nores GA. Immune response to Thomsen-Friedenreich disaccharide and glycan engineering. Immunol Cell Biol 2005; 83:405-12. [PMID: 16033536 DOI: 10.1111/j.1440-1711.2005.01348.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Cancer-associated mucins show frequent alterations of their oligosaccharide chain profile, with a switch to unmask normally cryptic O-glycan backbone and core regions. Epithelial tumour cells typically show overexpression of the uncovered Gal(beta)1-3GalNAc(alpha)-O-Ser/Thr (Core 1) structure, known as the T antigen or the Thomsen-Friedenreich antigen, the oligosaccharide chain of which is called the Thomsen-Friedenreich disaccharide (TFD). T antigen expression has been associated with immunosuppression, metastasis dissemination, and the proliferation of cancer cells. Several different strategies have been used to trigger a specific immune response to TFD. Natural T antigen and synthetic TFD residues have low immunodominance. In the T antigen, flexibility of the glycosidic bond reduces the immunogenicity of the sugar residue. Enhanced rigidity should favour certain glycan conformations and thereby improve TFD immunotargeting. We propose the term 'glycan engineering' for this approach. Such engineering of TFD should reduce the flexibility of its glycan moiety and thereby enhance its stability, rigidity and immunogenicity.
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Affiliation(s)
- Fernando J Irazoqui
- CIQUIBIC-CONICET/Department of Biological Chemistry, Faculty of Chemical Sciences, National University of Cordoba, Ciudad Universitaria, Cordoba, Argentina.
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42
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Karsten U, von Mensdorff-Pouilly S, Goletz S. What makes MUC1 a tumor antigen? Tumour Biol 2005; 26:217-20. [PMID: 16006776 DOI: 10.1159/000086956] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Accepted: 03/17/2005] [Indexed: 12/20/2022] Open
Abstract
The epithelial mucin 1 (MUC1) is an accepted serum tumor marker and cellular tumor antigen. We discuss recent views on the difference(s) between normal and tumor MUC1, and its implication for the development of cancer vaccines and antibody therapies, with special emphasis on the role of glycosylation.
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Affiliation(s)
- Uwe Karsten
- Max Delbrück Center for Molecular Medicine, Berlin-Buch, Germany.
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43
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Schuman JT, Grinstead JS, Apostolopoulos V, Campbell AP. Structural and dynamic consequences of increasing repeats in a MUC1 peptide tumor antigen. Biopolymers 2005; 77:107-20. [PMID: 15635690 DOI: 10.1002/bip.20190] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
MUC1 mucin is a large transmembrane glycoprotein whose extracelluler domain is composed of repeating units of a 20 amino acid sequence. In the cancer associated state, this protein expression becomes upregulated and underglycosylated. Previous studies, which show an enhanced binding of a 5-repeat over a 1-repeat MUC1 peptide to a panel of anti-MUC1 antibodies, have led us to investigate the structural and dynamic consequences of increasing repeat number. Two MUC1 peptides were studied: a 16mer corresponding to slightly less than one full repeat of the MUC1 tandem repeat sequence (GVTSAPDTRPAPGSTA) and a 40mer corresponding to two full repeats of the MUC1 sequence (VTSAPDTRPAPGSTAPPAHG)2. Isotopically labeled versions of these MUC1 peptides were cloned, expressed, purified, and evaluated structurally and dynamically using 15N- and 13C-edited NMR approaches. The data show that MUC1 structure, dynamics, and antibody binding affinity are invariant with increasing repeat number. In light of these results, we conclude that the enhanced antibody affinity of the 5-repeat over the 1-repeat MUC1 peptide is due to multivalency effects, and not due to the development of higher order structure in the longer length peptides. The implications of these results are discussed within the context of a multiple repeat MUC1 breast cancer vaccine design.
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Affiliation(s)
- Jason T Schuman
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
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Julenius K, Mølgaard A, Gupta R, Brunak S. Prediction, conservation analysis, and structural characterization of mammalian mucin-type O-glycosylation sites. Glycobiology 2004; 15:153-64. [PMID: 15385431 DOI: 10.1093/glycob/cwh151] [Citation(s) in RCA: 688] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
O-GalNAc-glycosylation is one of the main types of glycosylation in mammalian cells. No consensus recognition sequence for the O-glycosyltransferases is known, making prediction methods necessary to bridge the gap between the large number of known protein sequences and the small number of proteins experimentally investigated with regard to glycosylation status. From O-GLYCBASE a total of 86 mammalian proteins experimentally investigated for in vivo O-GalNAc sites were extracted. Mammalian protein homolog comparisons showed that a glycosylated serine or threonine is less likely to be precisely conserved than a nonglycosylated one. The Protein Data Bank was analyzed for structural information, and 12 glycosylated structures were obtained. All positive sites were found in coil or turn regions. A method for predicting the location for mucin-type glycosylation sites was trained using a neural network approach. The best overall network used as input amino acid composition, averaged surface accessibility predictions together with substitution matrix profile encoding of the sequence. To improve prediction on isolated (single) sites, networks were trained on isolated sites only. The final method combines predictions from the best overall network and the best isolated site network; this prediction method correctly predicted 76% of the glycosylated residues and 93% of the nonglycosylated residues. NetOGlyc 3.1 can predict sites for completely new proteins without losing its performance. The fact that the sites could be predicted from averaged properties together with the fact that glycosylation sites are not precisely conserved indicates that mucin-type glycosylation in most cases is a bulk property and not a very site-specific one. NetOGlyc 3.1 is made available at www.cbs.dtu.dk/services/netoglyc.
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Affiliation(s)
- Karin Julenius
- Center for Biological Sequence Analysis, BioCentrum, Building 208, Technical University of Denmark, DK-2800 Lyngby, Denmark.
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Bell SL, Xu G, Khatri IA, Wang R, Rahman S, Forstner JF. N-linked oligosaccharides play a role in disulphide-dependent dimerization of intestinal mucin Muc2. Biochem J 2003; 373:893-900. [PMID: 12744721 PMCID: PMC1223556 DOI: 10.1042/bj20030096] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2003] [Revised: 04/16/2003] [Accepted: 05/13/2003] [Indexed: 11/17/2022]
Abstract
Within the C-terminal domain of many secretory mucins is a 'cystine knot' (CK), which is needed for dimer formation in the endoplasmic reticulum. Previous studies indicate that in addition to an unpaired cysteine, the three intramolecular cystine bonds of the knot are important for stability of the dimers formed by rat intestinal mucin Muc2. The present study was undertaken to determine whether the two N-glycans N9 and N10, located near the first and second cysteines of the knot, also play a role in dimer formation. The C-terminal domain of rat Muc2 (RMC), a truncated RMC mutant containing the CK, and mutants lacking N9 and N10 sites, were expressed in COS-1 cells and the products monitored by radioactive [(35)S]Met/Cys metabolic pulse-chase and immunoprecipitation. Mutation of N9, but not N10, caused increased synthesis of dimers over a 2-h chase period. The N9 mutant remained associated with calreticulin for a prolonged period. About 34-38% of the total labelled products of RMC and its mutants was secreted into the media by 2 h, but the proportion in dimer form was dramatically reduced for the N9 mutant, suggesting lower dimer stability relative to RMC or its N10 mutant. We conclude that under normal conditions the presence of the N9 glycan functions to maintain a folding rate for mucin monomers that is sufficiently slow to allow structural maturation and stability of Muc2 dimers. To our knowledge this report is the first demonstration that a specific N-glycan plays a definitive role in mucin dimer formation.
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Affiliation(s)
- Sherilyn L Bell
- Division of Structural Biology & Biochemistry, Research Institute, The Hospital for Sick Children and the University of Toronto, 555 University Avenue, Toronto, ON M5G 1X8, Canada
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