1
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Pan Y, Xue Q, Yang Y, Shi T, Wang H, Song X, Luo Y, Liu W, Ren S, Cai Y, Nie Y, Song Z, Liu B, Li JP, Wei J. Glycoengineering-based anti-PD-1-iRGD peptide conjugate boosts antitumor efficacy through T cell engagement. Cell Rep Med 2024; 5:101590. [PMID: 38843844 PMCID: PMC11228665 DOI: 10.1016/j.xcrm.2024.101590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/22/2024] [Accepted: 05/13/2024] [Indexed: 06/21/2024]
Abstract
Despite the important breakthroughs of immune checkpoint inhibitors in recent years, the objective response rates remain limited. Here, we synthesize programmed cell death protein-1 (PD-1) antibody-iRGD cyclic peptide conjugate (αPD-1-(iRGD)2) through glycoengineering methods. In addition to enhancing tissue penetration, αPD-1-(iRGD)2 simultaneously engages tumor cells and PD-1+ T cells via dual targeting, thus mediating tumor-specific T cell activation and proliferation with mild effects on non-specific T cells. In multiple syngeneic mouse models, αPD-1-(iRGD)2 effectively reduces tumor growth with satisfactory biosafety. Moreover, results of flow cytometry and single-cell RNA-seq reveal that αPD-1-(iRGD)2 remodels the tumor microenvironment and expands a population of "better effector" CD8+ tumor infiltrating T cells expressing stem- and memory-associated genes, including Tcf7, Il7r, Lef1, and Bach2. Conclusively, αPD-1-(iRGD)2 is a promising antibody conjugate therapeutic beyond antibody-drug conjugate for cancer immunotherapy.
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Affiliation(s)
- Yunfeng Pan
- Department of Oncology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China; State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Qi Xue
- Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China
| | - Yi Yang
- Glyco-therapy Biotechnology Co. Ltd., Building 12, Hangzhou Pharmaceutical Town, 291 Fucheng Road, Xiasha Street, Qiantang District, Hangzhou, China
| | - Tao Shi
- Department of Oncology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Hanbing Wang
- Department of Oncology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Xueru Song
- Department of Oncology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Yuting Luo
- Department of Oncology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Wenqi Liu
- Department of Oncology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Shiji Ren
- Department of Oncology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Yiran Cai
- Department of Oncology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Yang Nie
- Department of Oncology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Zhentao Song
- Glyco-therapy Biotechnology Co. Ltd., Building 12, Hangzhou Pharmaceutical Town, 291 Fucheng Road, Xiasha Street, Qiantang District, Hangzhou, China
| | - Baorui Liu
- Department of Oncology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Jie P Li
- Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China.
| | - Jia Wei
- Department of Oncology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China; State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China; Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, China.
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2
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Zemkollari M, Oostenbrink C, Grabherr R, Staudacher E. Molecular cloning, characterisation and molecular modelling of two novel T-synthases from mollusc origin. Glycobiology 2024; 34:cwae013. [PMID: 38366999 PMCID: PMC11005171 DOI: 10.1093/glycob/cwae013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/09/2024] [Accepted: 02/11/2024] [Indexed: 02/19/2024] Open
Abstract
The glycoprotein-N-acetylgalactosamine β1,3-galactosyltransferase, known as T-synthase (EC 2.4.1.122), plays a crucial role in the synthesis of the T-antigen, which is the core 1 O-glycan structure. This enzyme transfers galactose from UDP-Gal to GalNAc-Ser/Thr. The T-antigen has significant functions in animal development, immune response, and recognition processes. Molluscs are a successful group of animals that inhabit various environments, such as freshwater, marine, and terrestrial habitats. They serve important roles in ecosystems as filter feeders and decomposers but can also be pests in agriculture and intermediate hosts for human and cattle parasites. The identification and characterization of novel carbohydrate active enzymes, such as T-synthase, can aid in the understanding of molluscan glycosylation abilities and their adaptation and survival abilities. Here, the T-synthase enzymes from the snail Pomacea canaliculata and the oyster Crassostrea gigas are identified, cloned, expressed, and characterized, with a focus on structural elucidation. The synthesized enzymes display core 1 β1,3-galactosyltransferase activity using pNP-α-GalNAc as substrate and exhibit similar biochemical parameters as previously characterised T-synthases from other species. While the enzyme from C. gigas shares the same structural parameters with the other enzymes characterised so far, the T-synthase from P. canaliculata lacks the consensus sequence CCSD, which was previously considered indispensable.
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Affiliation(s)
- Marilica Zemkollari
- Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Chris Oostenbrink
- Department of Material Sciences and Process Engineering, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Reingard Grabherr
- Department of Biotechnology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Erika Staudacher
- Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
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3
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Serna S, Artschwager R, Pérez-Martínez D, Lopez R, Reichardt NC. A Versatile Urea Type Linker for Functionalizing Natural Glycans and Its Validation in Glycan Arrays. Chemistry 2023; 29:e202301494. [PMID: 37347819 DOI: 10.1002/chem.202301494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 06/24/2023]
Abstract
The isolation from organisms and readily available glycoproteins has become an increasingly convenient source of N-glycans for multiple applications including glycan microarrays, as reference standards in glycan analysis or as reagents that improve bioavailability of protein and peptide therapeutics through conjugation. A problematic step in the isolation process on a preparative scale can be the attachment of a linker for the improved purification, separation, immobilization and quantification of the glycan structures. Addressing this issue, we firstly aimed for the development of an UV active linker for a fast and reliable attachment to anomeric glycosylamines via urea bond formation. Secondly, we validated the new linker on glycan arrays in a comparative study with a collection of N-glycans which were screened against various lectins. In total, we coupled four structurally varied N-glycans to four different linkers, immobilized all constructs on a microarray and compared their binding affinities to four plant and fungal lectins of widely described specificity. Our study shows that the urea type linker showed an overall superior performance for lectin binding and once more, highlights the often neglected influence of the choice of linker on lectin recognition.
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Affiliation(s)
- Sonia Serna
- Glycotechnology Group, Basque Research and Technology Alliance (BRTA) CIC biomaGUNE, Paseo Miramon 194, 20014, Donostia-San Sebastián, Spain
| | - Raik Artschwager
- Glycotechnology Group, Basque Research and Technology Alliance (BRTA) CIC biomaGUNE, Paseo Miramon 194, 20014, Donostia-San Sebastián, Spain
- Current address: Memorial Sloan Kettering Cancer Center New York, New York, 10065, USA
| | - Damián Pérez-Martínez
- Glycotechnology Group, Basque Research and Technology Alliance (BRTA) CIC biomaGUNE, Paseo Miramon 194, 20014, Donostia-San Sebastián, Spain
| | - Rosa Lopez
- Organic Chemistry Department I, University of the Basque Country (UPV/EHU), Paseo Manuel Lardizabal 3, 20018, Donostia-San Sebastián, Spain
| | - Niels-Christian Reichardt
- Glycotechnology Group, Basque Research and Technology Alliance (BRTA) CIC biomaGUNE, Paseo Miramon 194, 20014, Donostia-San Sebastián, Spain
- CIBER-BBN, Paseo Miramon 194, 20014, Donostia-San Sebastián, Spain
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4
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Prabhakar PK, Pereira JH, Taujale R, Shao W, Bharadwaj VS, Chapla D, Yang JY, Bomble YJ, Moremen KW, Kannan N, Hammel M, Adams PD, Scheller HV, Urbanowicz BR. Structural and biochemical insight into a modular β-1,4-galactan synthase in plants. NATURE PLANTS 2023; 9:486-500. [PMID: 36849618 PMCID: PMC10115243 DOI: 10.1038/s41477-023-01358-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 01/25/2023] [Indexed: 05/18/2023]
Abstract
Rhamnogalacturonan I (RGI) is a structurally complex pectic polysaccharide with a backbone of alternating rhamnose and galacturonic acid residues substituted with arabinan and galactan side chains. Galactan synthase 1 (GalS1) transfers galactose and arabinose to either extend or cap the β-1,4-galactan side chains of RGI, respectively. Here we report the structure of GalS1 from Populus trichocarpa, showing a modular protein consisting of an N-terminal domain that represents the founding member of a new family of carbohydrate-binding module, CBM95, and a C-terminal glycosyltransferase family 92 (GT92) catalytic domain that adopts a GT-A fold. GalS1 exists as a dimer in vitro, with stem domains interacting across the chains in a 'handshake' orientation that is essential for maintaining stability and activity. In addition to understanding the enzymatic mechanism of GalS1, we gained insight into the donor and acceptor substrate binding sites using deep evolutionary analysis, molecular simulations and biochemical studies. Combining all the results, a mechanism for GalS1 catalysis and a new model for pectic galactan side-chain addition are proposed.
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Affiliation(s)
- Pradeep Kumar Prabhakar
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oakridge, TN, USA
| | - Jose Henrique Pereira
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Rahil Taujale
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Wanchen Shao
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Vivek S Bharadwaj
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Digantkumar Chapla
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Jeong-Yeh Yang
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Yannick J Bomble
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Kelley W Moremen
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Natarajan Kannan
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Michal Hammel
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Paul D Adams
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Bioengineering, University of California, Berkeley, CA, USA
| | - Henrik V Scheller
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Breeanna R Urbanowicz
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA.
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA.
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oakridge, TN, USA.
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5
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Ruhnau J, Grote V, Juarez-Osorio M, Bruder D, Mahour R, Rapp E, Rexer TFT, Reichl U. Cell-Free Glycoengineering of the Recombinant SARS-CoV-2 Spike Glycoprotein. Front Bioeng Biotechnol 2021; 9:699025. [PMID: 34485255 PMCID: PMC8415157 DOI: 10.3389/fbioe.2021.699025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 07/15/2021] [Indexed: 01/23/2023] Open
Abstract
The baculovirus-insect cell expression system is readily utilized to produce viral glycoproteins for research as well as for subunit vaccines and vaccine candidates, for instance against SARS-CoV-2 infections. However, the glycoforms of recombinant proteins derived from this expression system are inherently different from mammalian cell-derived glycoforms with mainly complex-type N-glycans attached, and the impact of these differences in protein glycosylation on the immunogenicity is severely under investigated. This applies also to the SARS-CoV-2 spike glycoprotein, which is the antigen target of all licensed vaccines and vaccine candidates including virus like particles and subunit vaccines that are variants of the spike protein. Here, we expressed the transmembrane-deleted human β-1,2 N-acetlyglucosamintransferases I and II (MGAT1ΔTM and MGAT2ΔTM) and the β-1,4-galactosyltransferase (GalTΔTM) in E. coli to in-vitro remodel the N-glycans of a recombinant SARS-CoV-2 spike glycoprotein derived from insect cells. In a cell-free sequential one-pot reaction, fucosylated and afucosylated paucimannose-type N-glycans were converted to complex-type galactosylated N-glycans. In the future, this in-vitro glycoengineering approach can be used to efficiently generate a wide range of N-glycans on antigens considered as vaccine candidates for animal trials and preclinical testing to better characterize the impact of N-glycosylation on immunity and to improve the efficacy of protein subunit vaccines.
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Affiliation(s)
- Johannes Ruhnau
- Max Planck Institute for Dynamics of Complex Technical Systems, Bioprocess Engineering, Magdeburg, Germany
| | - Valerian Grote
- Max Planck Institute for Dynamics of Complex Technical Systems, Bioprocess Engineering, Magdeburg, Germany
| | - Mariana Juarez-Osorio
- Max Planck Institute for Dynamics of Complex Technical Systems, Bioprocess Engineering, Magdeburg, Germany
| | - Dunja Bruder
- Infection Immunology, Institute of Medical Microbiology, Infection Prevention and Control, Health Campus Immunology, Infectiology and Inflammation, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
- Immune Regulation Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Reza Mahour
- Max Planck Institute for Dynamics of Complex Technical Systems, Bioprocess Engineering, Magdeburg, Germany
| | - Erdmann Rapp
- Max Planck Institute for Dynamics of Complex Technical Systems, Bioprocess Engineering, Magdeburg, Germany
- glyXera GmbH, Magdeburg, Germany
| | - Thomas F. T. Rexer
- Max Planck Institute for Dynamics of Complex Technical Systems, Bioprocess Engineering, Magdeburg, Germany
| | - Udo Reichl
- Max Planck Institute for Dynamics of Complex Technical Systems, Bioprocess Engineering, Magdeburg, Germany
- Otto-von-Guericke University Magdeburg, Chair of Bioprocess Engineering, Magdeburg, Germany
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6
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Hao Y, Créquer-Grandhomme A, Javier N, Singh A, Chen H, Manzanillo P, Lo MC, Huang X. Structures and mechanism of human glycosyltransferase β1,3-N-acetylglucosaminyltransferase 2 (B3GNT2), an important player in immune homeostasis. J Biol Chem 2020; 296:100042. [PMID: 33158990 PMCID: PMC7948737 DOI: 10.1074/jbc.ra120.015306] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 11/02/2020] [Accepted: 11/06/2020] [Indexed: 12/16/2022] Open
Abstract
β1,3-N-acetylglucosaminyltransferases (B3GNTs) are Golgi-resident glycosyltransferases involved in the biosynthesis of poly-N-acetyl-lactosamine chains. They catalyze the addition of the N-acetylglucosamine to the N-acetyl-lactosamine repeat as a key step of the chain elongation process. Poly-N-acetyl-lactosamine is involved in the immune system in many ways. Particularly, its long chain has been demonstrated to suppress excessive immune responses. Among the characterized B3GNTs, B3GNT2 is the major poly-N-acetyl-lactosamine synthase, and deletion of its coding gene dramatically reduced the cell surface poly-N-acetyl-lactosamine and led to hypersensitive and hyperresponsive immunocytes. Despite the extensive functional studies, no structural information is available to understand the molecular mechanism of B3GNT2, as well as other B3GNTs. Here we present the structural and kinetic studies of the human B3GNT2. Five crystal structures of B3GNT2 have been determined in the unliganded, donor substrate-bound, acceptor substrate-bound, and product(s)-bound states at resolutions ranging from 1.85 to 2.35 Å. Kinetic study shows that the transglycosylation reaction follows a sequential mechanism. Critical residues involved in recognition of both donor and acceptor substrates as well as catalysis are identified. Mutations of these invariant residues impair B3GNT2 activity in cell assays. Structural comparison with other glycosyltransferases such as mouse Fringe reveals a novel N-terminal helical domain of B3GNTs that may stabilize the catalytic domain and distinguish among different acceptor substrates.
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Affiliation(s)
- Yue Hao
- Department of Molecular Engineering, Amgen Research, Cambridge, Massachusetts, USA; Amgen Postdoctoral Fellow Program, Amgen Research, Cambridge, Massachusetts, USA.
| | | | - Noelle Javier
- Department of Discovery Technologies, Amgen Research, South San Francisco, California, USA
| | - Aman Singh
- Department of Discovery Attribute Sciences, Amgen Research, South San Francisco, California, USA
| | - Hao Chen
- Department of Protein Technologies, Amgen Research, Cambridge, Massachusetts, USA
| | - Paolo Manzanillo
- Department of Inflammation and Oncology, Amgen Research, South San Francisco, California, USA
| | - Mei-Chu Lo
- Department of Discovery Technologies, Amgen Research, South San Francisco, California, USA
| | - Xin Huang
- Department of Molecular Engineering, Amgen Research, Cambridge, Massachusetts, USA.
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7
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Pham J, Hernandez A, Cioce A, Achilli S, Goti G, Vivès C, Thepaut M, Bernardi A, Fieschi F, Reichardt NC. Chemo-Enzymatic Synthesis of S. mansoni O-Glycans and Their Evaluation as Ligands for C-Type Lectin Receptors MGL, DC-SIGN, and DC-SIGNR. Chemistry 2020; 26:12818-12830. [PMID: 32939912 DOI: 10.1002/chem.202000291] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/07/2020] [Indexed: 12/28/2022]
Abstract
Due to their interactions with C-type lectin receptors (CLRs), glycans from the helminth Schistosoma mansoni represent promising leads for treatment of autoimmune diseases, allergies or cancer. We chemo-enzymatically synthesized nine O-glycans based on the two predominant O-glycan cores observed in the infectious stages of schistosomiasis, the mucin core 2 and the S. mansoni core. The O-glycans were fucosylated next to a selection of N-glycans directly on a microarray slide using a recombinant fucosyltransferase and GDP-fucose or GDP-6-azidofucose as donor. Binding assays with fluorescently labelled human CLRs DC-SIGN, DC-SIGNR and MGL revealed the novel O-glycan O8 as the best ligand for MGL from our panel. Significant binding to DC-SIGN was also found for azido-fucosylated glycans. Contrasting binding specificities were observed between the monovalent carbohydrate recognition domain (CRD) and the tetravalent extracellular domain (ECD) of DC-SIGNR.
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Affiliation(s)
- Julie Pham
- CIC biomaGUNE, Glycotechnology Group, Paseo Miramón 182, 20014, San Sebastian, Spain
| | - Alvaro Hernandez
- CIC biomaGUNE, Glycotechnology Group, Paseo Miramón 182, 20014, San Sebastian, Spain.,Asparia Glycomics S.L., Mikeletegi 83, 20009, San Sebastian, Spain
| | - Anna Cioce
- CIC biomaGUNE, Glycotechnology Group, Paseo Miramón 182, 20014, San Sebastian, Spain
| | - Silvia Achilli
- CNRS, CEA, Institut de Biologie Structurale, Université Grenoble Alpes, 38100, Grenoble, France.,Present address: DCM, UMR 5250, Université Grenoble Alpes, CNRS, 38000, Grenoble, France
| | - Giulio Goti
- Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133, Milano, Italy
| | - Corinne Vivès
- CNRS, CEA, Institut de Biologie Structurale, Université Grenoble Alpes, 38100, Grenoble, France
| | - Michel Thepaut
- CNRS, CEA, Institut de Biologie Structurale, Université Grenoble Alpes, 38100, Grenoble, France
| | - Anna Bernardi
- Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133, Milano, Italy
| | - Franck Fieschi
- CNRS, CEA, Institut de Biologie Structurale, Université Grenoble Alpes, 38100, Grenoble, France
| | - Niels-Christian Reichardt
- CIC biomaGUNE, Glycotechnology Group, Paseo Miramón 182, 20014, San Sebastian, Spain.,CIBER-BBN, Paseo Miramón 182, 20014, San Sebastian, Spain.,Basque Research and Technology Alliance (BRTA), Paseo Miramón 182, 20014, San Sebastian, Spain
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8
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Production of a bispecific antibody targeting TNF-α and C5a in Pichia pastoris and its therapeutic potential in rheumatoid arthritis. Biotechnol Lett 2020; 42:557-569. [PMID: 32040674 DOI: 10.1007/s10529-020-02830-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 02/02/2020] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To provide an alternative therapeutic modality for rheumatoid arthritis (RA), a novel bispecific antibody (BsAb) targeting human tumor necrosis factor α (TNF-α) and human complement component C5a was constructed. RESULTS BsAb was expressed in Pichia pastoris and secreted into the culture medium as a functional protein. In vitro functional study demonstrated that BsAb could simultaneously bind to TNF-α and C5a and neutralize their biological actions. Furthermore, BsAb showed significant improvements in both the antigen-binding affinity and the neutralizing ability as compared to its original antibodies produced in E. coli. It was also found that TNF-α and C5a had an additive/synergistic effect on promoting the production of inflammatory cytokines and chemokines and C5a receptor (C5aR) expression in human macrophages. Compared to single inhibition of TNF-α or C5a with respective antibody, BsAb showed a superior efficacy in blocking inflammatory cytokines, chemokines, and C5aR response, as well as in lowering the C5a-mediated chemotaxis of macrophages via C5aR in vitro. CONCLUSIONS With improved production processing and the ability to simultaneously block TNF-α and C5a action, BsAb has a great potential to be developed into a therapeutic agent and may offer a better therapeutic index for RA.
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9
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van Geel R, Wijdeven MA, Heesbeen R, Verkade JMM, Wasiel AA, van Berkel SS, van Delft FL. Chemoenzymatic Conjugation of Toxic Payloads to the Globally Conserved N-Glycan of Native mAbs Provides Homogeneous and Highly Efficacious Antibody-Drug Conjugates. Bioconjug Chem 2015; 26:2233-42. [PMID: 26061183 DOI: 10.1021/acs.bioconjchem.5b00224] [Citation(s) in RCA: 181] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A robust, generally applicable, nongenetic technology is presented to convert monoclonal antibodies into stable and homogeneous ADCs. Starting from a native (nonengineered) mAb, a chemoenzymatic protocol allows for the highly controlled attachment of any given payload to the N-glycan residing at asparagine-297, based on a two-stage process: first, enzymatic remodeling (trimming and tagging with azide), followed by ligation of the payload based on copper-free click chemistry. The technology, termed GlycoConnect, is applicable to any IgG isotype irrespective of glycosylation profile. Application to trastuzumab and maytansine, both components of the marketed ADC Kadcyla, demonstrate a favorable in vitro and in vivo efficacy for GlycoConnect ADC. Moreover, the superiority of the native glycan as attachment site was demonstrated by in vivo comparison to a range of trastuzumab-based glycosylation mutants. A side-by-side comparison of the copper-free click probes bicyclononyne (BCN) and a dibenzoannulated cyclooctyne (DBCO) showed a surprising difference in conjugation efficiency in favor of BCN, which could be even further enhanced by introduction of electron-withdrawing fluoride substitutions onto the azide. The resulting mAb-conjugates were in all cases found to be highly stable, which in combination with the demonstrated efficacy warrants ADCs with a superior therapeutic index.
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Affiliation(s)
- Remon van Geel
- SynAffix BV , Pivot Park, Molenstraat 110, 5342 CC, Oss, The Netherlands
| | - Marloes A Wijdeven
- SynAffix BV , Pivot Park, Molenstraat 110, 5342 CC, Oss, The Netherlands
| | - Ryan Heesbeen
- SynAffix BV , Pivot Park, Molenstraat 110, 5342 CC, Oss, The Netherlands
| | - Jorge M M Verkade
- SynAffix BV , Pivot Park, Molenstraat 110, 5342 CC, Oss, The Netherlands
| | - Anna A Wasiel
- SynAffix BV , Pivot Park, Molenstraat 110, 5342 CC, Oss, The Netherlands
| | | | - Floris L van Delft
- SynAffix BV , Pivot Park, Molenstraat 110, 5342 CC, Oss, The Netherlands
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10
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Brzezicka K, Echeverria B, Serna S, van Diepen A, Hokke CH, Reichardt NC. Synthesis and microarray-assisted binding studies of core xylose and fucose containing N-glycans. ACS Chem Biol 2015; 10:1290-302. [PMID: 25664929 DOI: 10.1021/cb501023u] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis of a collection of 33 xylosylated and core-fucosylated N-glycans found only in nonmammalian organisms such as plants and parasitic helminths has been achieved by employing a highly convergent chemo-enzymatic approach. The influence of these core modifications on the interaction with plant lectins, with the human lectin DC-SIGN (Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Nonintegrin), and with serum antibodies from schistosome-infected individuals was studied. Core xylosylation markedly reduced or completely abolished binding to several mannose-binding plant lectins and to DC-SIGN, a C-type lectin receptor present on antigen presenting cells. Employing the synthetic collection of core-fucosylated and core-xylosylated N-glycans in the context of a larger glycan array including structures lacking these core modifications, we were able to dissect core xylose and core fucose specific antiglycan antibody responses in S. mansoni infection sera, and we observed clear and immunologically relevant differences between children and adult groups infected with this parasite. The work presented here suggests that, quite similar to bisecting N-acetylglucosamine, core xylose distorts the conformation of the unsubstituted glycan, with important implications for the immunogenicity and protein binding properties of complex N-glycans.
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Affiliation(s)
- Katarzyna Brzezicka
- Glycotechnology
Laboratory, CIC biomaGUNE, Paseo Miramón 182, 20009 San Sebastian, Spain
| | - Begoña Echeverria
- Glycotechnology
Laboratory, CIC biomaGUNE, Paseo Miramón 182, 20009 San Sebastian, Spain
| | - Sonia Serna
- Glycotechnology
Laboratory, CIC biomaGUNE, Paseo Miramón 182, 20009 San Sebastian, Spain
| | - Angela van Diepen
- Parasite
Glycobiology Group, Department of Parasitology, Leiden University Medical Center, P.O.
Box 9600, 2300 RC Leiden, The Netherlands
| | - Cornelis H. Hokke
- Parasite
Glycobiology Group, Department of Parasitology, Leiden University Medical Center, P.O.
Box 9600, 2300 RC Leiden, The Netherlands
| | - Niels-Christian Reichardt
- Glycotechnology
Laboratory, CIC biomaGUNE, Paseo Miramón 182, 20009 San Sebastian, Spain
- CIBER BBN, Paseo Miramón
182, 20009 San Sebastian, Spain
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11
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Liu MY, Hu XP, Xie M, Jiang SJ, Li LJ, Liu DX, Yang XS. Secretory expression of a bispecific antibody targeting tumor necrosis factor and ED-B fibronectin in Pichia pastoris and its functional analysis. Biotechnol Lett 2014; 36:2425-31. [PMID: 25129049 DOI: 10.1007/s10529-014-1630-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 08/07/2014] [Indexed: 12/19/2022]
Abstract
Specific targeting of tumor necrosis factor (TNF)-α antagonist to the inflamed site could increase its efficacy and reduce side-effects. Here, we constructed a bispecific diabody (BsDb) that targets TNF-α and ED-B-containing fibronectin, a fibronectin isoform specifically expressed in the pannus of the inflamed synovium in rheumatoid arthritis. BsDb was secreted from Pichia pastoris as functional protein and was purified to homogeneity. BsDb could simultaneously bind to human TNF-α and B-FN and neutralize TNF-α action. Additionally, BsDb showed a significant gain both in the antigen-binding affinity and in TNF-α-neutralizing ability as compared to its original antibodies, L19 and anti-TNF-α scFv, which were produced in E. coli. BsDb was constructed and was endowed with enhanced bioactivities and improved production processing. Therefore, it holds great potential for in vivo applications.
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Affiliation(s)
- Meng-yuan Liu
- Center for Infection and Immunity Research, School of Life Sciences, Hubei University, Youyi Road 368, Wuhan, 430062, China,
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12
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Aryal RP, Ju T, Cummings RD. Identification of a novel protein binding motif within the T-synthase for the molecular chaperone Cosmc. J Biol Chem 2014; 289:11630-11641. [PMID: 24616093 DOI: 10.1074/jbc.m114.555870] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Prior studies suggested that the core 1 β3-galactosyltransferase (T-synthase) is a specific client of the endoplasmic reticulum chaperone Cosmc, whose function is required for T-synthase folding, activity, and consequent synthesis of normal O-glycans in all vertebrate cells. To explore whether the T-synthase encodes a specific recognition motif for Cosmc, we used deletion mutagenesis to identify a cryptic linear and relatively hydrophobic peptide in the N-terminal stem region of the T-synthase that is essential for binding to Cosmc (Cosmc binding region within T-synthase, or CBRT). Using this sequence information, we synthesized a peptide containing CBRT and found that it directly interacts with Cosmc and also inhibits Cosmc-assisted in vitro refolding of denatured T-synthase. Moreover, engineered T-synthase carrying mutations within CBRT exhibited diminished binding to Cosmc that resulted in the formation of inactive T-synthase. To confirm the general recognition of CBRT by Cosmc, we performed a domain swap experiment in which we inserted the stem region of the T-synthase into the human β4GalT1 and found that the CBRT element can confer Cosmc binding onto the β4GalT1 chimera. Thus, CBRT is a unique recognition motif for Cosmc to promote its regulation and formation of active T-synthase and represents the first sequence-specific chaperone recognition system in the ER/Golgi required for normal protein O-glycosylation.
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Affiliation(s)
- Rajindra P Aryal
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Tongzhong Ju
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322.
| | - Richard D Cummings
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322.
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13
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Zeglis BM, Davis CB, Aggeler R, Kang HC, Chen A, Agnew BJ, Lewis JS. Enzyme-mediated methodology for the site-specific radiolabeling of antibodies based on catalyst-free click chemistry. Bioconjug Chem 2013; 24:1057-67. [PMID: 23688208 DOI: 10.1021/bc400122c] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
An enzyme- and click chemistry-mediated methodology for the site-selective radiolabeling of antibodies on the heavy chain glycans has been developed and validated. To this end, a model system based on the prostate specific membrane antigen-targeting antibody J591, the positron-emitting radiometal (89)Zr, and the chelator desferrioxamine has been employed. The methodology consists of four steps: (1) the removal of sugars on the heavy chain region of the antibody to expose terminal N-acetylglucosamine residues; (2) the incorporation of azide-modified N-acetylgalactosamine monosaccharides into the glycans of the antibody; (3) the catalyst-free click conjugation of desferrioxamine-modified dibenzocyclooctynes to the azide-bearing sugars; and (4) the radiolabeling of the chelator-modified antibody with (89)Zr. The site-selective labeling methodology has proven facile, reproducible, and robust, producing (89)Zr-labeled radioimmunoconjguates that display high stability and immunoreactivity in vitro (>95%) in addition to highly selective tumor uptake (67.5 ± 5.0%ID/g) and tumor-to-background contrast in athymic nude mice bearing PSMA-expressing subcutaneous LNCaP xenografts. Ultimately, this strategy could play a critical role in the development of novel well-defined and highly immunoreactive radioimmunoconjugates for both the laboratory and clinic.
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Affiliation(s)
- Brian M Zeglis
- Department of Radiology and the Program in Molecular Pharmacology and Chemistry, Memorial Sloan-Kettering Cancer Center, New York, New York, United States
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14
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Ramakrishnan B, Qasba PK. In vitro folding of β-1,4galactosyltransferase and polypeptide-α-N-acetylgalactosaminyltransferase from the inclusion bodies. Methods Mol Biol 2013; 1022:321-33. [PMID: 23765672 DOI: 10.1007/978-1-62703-465-4_24] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The aim of this article is to present a unique in vitro folding technique for glycosyltransferases to generate active proteins that can be used for X-ray crystallographic and bioconjugation protocols. Although a number of in vitro refolding methods are available, β1,4galactosyltransferases in large quantities can be made using the current protocol only. This technique is not only limited to glycosyltransferases alone but has been successfully used to refold single-chain antibodies and other molecules. Although this in vitro folding method is quite similar to other methods, it differs from them by the use of S-sulfonation of the inclusion bodies before setting up the in vitro refolding of the protein.
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Affiliation(s)
- Boopathy Ramakrishnan
- Structural Glycobiology Section and Basic Science Program, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Center for Cancer Research, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
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15
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Mercer N, Ramakrishnan B, Boeggeman E, Qasba PK. Applications of site-specific labeling to study HAMLET, a tumoricidal complex of α-lactalbumin and oleic acid. PLoS One 2011; 6:e26093. [PMID: 22016817 PMCID: PMC3189925 DOI: 10.1371/journal.pone.0026093] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 09/19/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Alpha-lactalbumin (α-LA) is a calcium-bound mammary gland-specific protein that is found in milk. This protein is a modulator of β1,4-galactosyltransferase enzyme, changing its acceptor specificity from N-acetyl-glucosamine to glucose, to produce lactose, milk's main carbohydrate. When calcium is removed from α-LA, it adopts a molten globule form, and this form, interestingly, when complexed with oleic acid (OA) acquires tumoricidal activity. Such a complex made from human α-LA (hLA) is known as HAMLET (Human A-lactalbumin Made Lethal to Tumor cells), and its tumoricidal activity has been well established. METHODOLOGY/PRINCIPAL FINDINGS In the present work, we have used site-specific labeling, a technique previously developed in our laboratory, to label HAMLET with biotin, or a fluoroprobe for confocal microscopy studies. In addition to full length hLA, the α-domain of hLA (αD-hLA) alone is also included in the present study. We have engineered these proteins with a 17-amino acid C-terminal extension (hLA-ext and αD-hLA-ext). A single Thr residue in this extension is glycosylated with 2-acetonyl-galactose (C2-keto-galactose) using polypeptide-α-N-acetylgalactosaminyltransferase II (ppGalNAc-T2) and further conjugated with aminooxy-derivatives of fluoroprobe or biotin molecules. CONCLUSIONS/SIGNIFICANCE We found that the molten globule form of hLA and αD-hLA proteins, with or without C-terminal extension, and with and without the conjugated fluoroprobe or biotin molecule, readily form a complex with OA and exhibits tumoricidal activity similar to HAMLET made with full-length hLA protein. The confocal microscopy studies with fluoroprobe-labeled samples show that these proteins are internalized into the cells and found even in the nucleus only when they are complexed with OA. The HAMLET conjugated with a single biotin molecule will be a useful tool to identify the cellular components that are involved with it in the tumoricidal activity.
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Affiliation(s)
- Natalia Mercer
- Structural Glycobiology Section, CCR-Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, Maryland, United States of America
| | - Boopathy Ramakrishnan
- Structural Glycobiology Section, CCR-Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, Maryland, United States of America
- Basic Science Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland, United States of America
| | - Elizabeth Boeggeman
- Structural Glycobiology Section, CCR-Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, Maryland, United States of America
- Basic Science Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland, United States of America
| | - Pradman K. Qasba
- Structural Glycobiology Section, CCR-Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, Maryland, United States of America
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16
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Bioconjugation using mutant glycosyltransferases for the site-specific labeling of biomolecules with sugars carrying chemical handles. Methods Mol Biol 2011; 751:281-96. [PMID: 21674337 DOI: 10.1007/978-1-61779-151-2_17] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
This chapter presents a technique that employs mutant glycosyltransferase enzymes for the site-specific bioconjugation of biomolecules via a glycan moiety to facilitate the development of a targeted drug delivery system. The target specificity of this methodology is based on unique sugar residues that are present on glycoproteins or engineered glycopeptides. The glycosyltransferases used in this approach have been manipulated in a way that confers the ability to transfer a modified sugar residue with a chemical handle to a sugar moiety of the glycoprotein or to a polypeptide tag of an engineered nonglycoprotein. The availability of the modified sugar moiety thus makes it possible to link cargo molecules at specific sites. The cargo may be comprised of, for example, biotin or fluorescent tags for detection, imaging agents for magnetic resonance imaging (MRI), or cytotoxic drugs for cancer therapy.
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17
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Jafari R, Holm P, Piercecchi M, Sundström BE. Construction of divalent anti-keratin 8 single-chain antibodies (sc(Fv)(2)), expression in Pichia pastoris and their reactivity with multicellular tumor spheroids. J Immunol Methods 2010; 364:65-76. [PMID: 21093447 DOI: 10.1016/j.jim.2010.11.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2010] [Revised: 10/15/2010] [Accepted: 11/10/2010] [Indexed: 11/28/2022]
Abstract
Single-chain variable fragments (scFvs) are small monovalent recombinant antibody fragments that retain the specificity of their parent immunoglobulins. ScFvs are excellent building blocks for new and improved immunodiagnostic and therapeutic proteins. However, the monovalency and the rapid renal elimination of scFvs result in poor tumor accumulation and retention. Engineering divalent antibody fragments is an excellent way to address these shortcomings. In this study, covalent divalent single-chain variable fragments (sc(Fv)(2)s), were constructed from the monovalent anti-keratin 8 scFvs, TS1-218 and its mutant, HE1-Q. The scFvs and sc(Fv)(2)s were expressed in the methylotrophic yeast Pichia pastoris, utilizing the alpha-factor secretion signal (α-factor) for extracellular secretion. The immunoreactivity and specificity of the antibody fragments were analyzed with enzyme-linked immunosorbent assay (ELISA) and the uptake and retention of the (125)I labeled antibody fragments were evaluated using HeLa HEp-2 multicellular tumor spheroids (MCTSs). Analysis of the antibody fragments demonstrated that parts of the α-factor remained at the N-terminal of the antibody fragments. Despite incomplete processing of the α-factor, the antibody fragments were functional where the sc(Fv)(2)s gave a three-fold stronger signal in ELISA compared to their scFv counterparts and the mutant antibodies demonstrated a stronger signal than their initial wild types. In addition, the sc(Fv)(2)s DiTS1-218 and DiHE1-Q displayed an approximately two-fold higher uptake and were retained to a larger extent in the MCTS, demonstrating a 3.9 and 9.4-fold increase in half-life respectively compared to their corresponding scFvs. In conclusion, expression in P. pastoris improved the yield 20-fold and facilitated the purification of the antibody fragments. Furthermore, the sc(Fv)(2)s presented a higher functional affinity to K 8 both in ELISA and MCTS compared to the scFvs with DiHE1-Q being the best candidate for further studies.
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Affiliation(s)
- Rozbeh Jafari
- Department of Chemistry and Biomedical Sciences, Karlstad University, S-651 88 Karlstad, Sweden
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18
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Ramakrishnan B, Qasba PK. Crystal structure of the catalytic domain of Drosophila beta1,4-Galactosyltransferase-7. J Biol Chem 2010; 285:15619-15626. [PMID: 20236943 PMCID: PMC2865272 DOI: 10.1074/jbc.m109.099564] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Revised: 02/24/2010] [Indexed: 11/06/2022] Open
Abstract
The beta1,4-galactosyltransferase-7 (beta4Gal-T7) enzyme, one of seven members of the beta4Gal-T family, transfers in the presence of manganese Gal from UDP-Gal to an acceptor sugar (xylose) that is attached to a side chain hydroxyl group of Ser/Thr residues of proteoglycan proteins. It exhibits the least protein sequence similarity with the other family members, including the well studied family member beta4Gal-T1, which, in the presence of manganese, transfers Gal from UDP-Gal to GlcNAc. We report here the crystal structure of the catalytic domain of beta4Gal-T7 from Drosophila in the presence of manganese and UDP at 1.81 A resolution. In the crystal structure, a new manganese ion-binding motif (HXH) has been observed. Superposition of the crystal structures of beta4Gal-T7 and beta4Gal-T1 shows that the catalytic pocket and the substrate-binding sites in these proteins are similar. Compared with GlcNAc, xylose has a hydroxyl group (instead of an N-acetyl group) at C2 and lacks the CH(2)OH group at C5; thus, these protein structures show significant differences in their acceptor-binding site. Modeling of xylose in the acceptor-binding site of the beta4Gal-T7 crystal structure shows that the aromatic side chain of Tyr(177) interacts strongly with the C5 atom of xylose, causing steric hindrance to any additional group at C5. Because Drosophila Cd7 has a 73% protein sequence similarity to human Cd7, the present crystal structure offers a structure-based explanation for the mutations in human Cd7 that have been linked to Ehlers-Danlos syndrome.
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Affiliation(s)
- Boopathy Ramakrishnan
- Structural Glycobiology Section, National Institutes of Health, Frederick, Maryland 21702; Basic Research Program, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Center for Cancer Research, NCI, National Institutes of Health, Frederick, Maryland 21702
| | - Pradman K Qasba
- Structural Glycobiology Section, National Institutes of Health, Frederick, Maryland 21702.
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Pasek M, Boeggeman E, Ramakrishnan B, Qasba PK. Galectin-1 as a fusion partner for the production of soluble and folded human beta-1,4-galactosyltransferase-T7 in E. coli. Biochem Biophys Res Commun 2010; 394:679-84. [PMID: 20226765 PMCID: PMC2859968 DOI: 10.1016/j.bbrc.2010.03.051] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Accepted: 03/07/2010] [Indexed: 12/16/2022]
Abstract
The expression of recombinant proteins in Escherichia coli often leads to inactive aggregated proteins known as the inclusion bodies. To date, the best available tool has been the use of fusion tags, including the carbohydrate-binding protein; e.g., the maltose-binding protein (MBP) that enhances the solubility of recombinant proteins. However, none of these fusion tags work universally with every partner protein. We hypothesized that galectins, which are also carbohydrate-binding proteins, may help as fusion partners in folding the mammalian proteins in E. coli. Here we show for the first time that a small soluble lectin, human galectin-1, one member of a large galectin family, can function as a fusion partner to produce soluble folded recombinant human glycosyltransferase, beta-1,4-galactosyltransferase-7 (beta4Gal-T7), in E. coli. The enzyme beta4Gal-T7 transfers galactose to xylose during the synthesis of the tetrasaccharide linker sequence attached to a Ser residue of proteoglycans. Without a fusion partner, beta4Gal-T7 is expressed in E. coli as inclusion bodies. We have designed a new vector construct, pLgals1, from pET-23a that includes the sequence for human galectin-1, followed by the Tev protease cleavage site, a 6x His-coding sequence, and a multi-cloning site where a cloned gene is inserted. After lactose affinity column purification of galectin-1-beta4Gal-T7 fusion protein, the unique protease cleavage site allows the protein beta4Gal-T7 to be cleaved from galectin-1 that binds and elutes from UDP-agarose column. The eluted protein is enzymatically active, and shows CD spectra comparable to the folded beta4Gal-T1. The engineered galectin-1 vector could prove to be a valuable tool for expressing other proteins in E. coli.
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Affiliation(s)
- Marta Pasek
- Structural Glycobiology Section, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, MD 2170, USA
| | - Elizabeth Boeggeman
- Structural Glycobiology Section, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, MD 2170, USA
- Basic Research Program, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, MD 2170, USA
| | - Boopathy Ramakrishnan
- Structural Glycobiology Section, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, MD 2170, USA
- Basic Research Program, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, MD 2170, USA
| | - Pradman K. Qasba
- Structural Glycobiology Section, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, MD 2170, USA
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Boeggeman E, Ramakrishnan B, Pasek M, Manzoni M, Puri A, Loomis KH, Waybright TJ, Qasba PK. Site specific conjugation of fluoroprobes to the remodeled Fc N-glycans of monoclonal antibodies using mutant glycosyltransferases: application for cell surface antigen detection. Bioconjug Chem 2009; 20:1228-36. [PMID: 19425533 DOI: 10.1021/bc900103p] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The Fc N-glycan chains of four therapeutic monoclonal antibodies (mAbs), namely, Avastin, Rituxan, Remicade, and Herceptin, released by PNGase F, show by MALDI analysis that these biantennary N-glycans are a mixture of G0, G1, and G2 glycoforms. The G0 glycoform has no galactose on the terminal GlcNAc residues, and the G1 and G2 glycoforms have one or two terminal galactose residues, respectively, while no N-glycan with terminal sialic acid residue is observed. We show here that under native conditions we can convert the N-glycans of these mAbs to a homogeneous population of G0 glycoform using beta1,4 galactosidase from Streptococcus pneumoniae. The G0 glycoforms of mAbs can be galactosylated with a modified galactose having a chemical handle at the C2 position, such as ketone or azide, using a mutant beta1,4-galactosyltransferase (beta1,4Gal-T1-Y289L). The addition of the modified galactose at a specific glycan residue of a mAb permits the coupling of a biomolecule that carries an orthogonal reactive group. The linking of a biotinylated or a fluorescent dye carrying derivatives selectively occurs with the modified galactose, C2-keto-Gal, at the heavy chain of these mAbs, without altering their antigen binding activities, as shown by indirect enzyme linked immunosorbent assay (ELISA) and fluorescence activated cell sorting (FACS) methods. Our results demonstrate that the linking of cargo molecules to mAbs via glycans could prove to be an invaluable tool for potential drug targeting by immunotherapeutic methods.
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Affiliation(s)
- Elizabeth Boeggeman
- Structural Glycobiology Section, CCR-Nanobiology Program, SAIC-Frederick, Inc., Frederick, Maryland 21702, USA
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21
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Krupička M, Tvaroška I. Hybrid Quantum Mechanical/Molecular Mechanical Investigation of the β-1,4-Galactosyltransferase-I Mechanism. J Phys Chem B 2009; 113:11314-9. [DOI: 10.1021/jp904716t] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Martin Krupička
- Contribution from the Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravska cesta 9, 845 38 Bratislava, Slovak Republic
| | - Igor Tvaroška
- Contribution from the Institute of Chemistry, Centre for Glycomics, Slovak Academy of Sciences, Dúbravska cesta 9, 845 38 Bratislava, Slovak Republic
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22
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Ramakrishnan B, Boeggeman E, Manzoni M, Zhu Z, Loomis K, Puri A, Dimitrov DS, Qasba PK. Multiple site-specific in vitro labeling of single-chain antibody. Bioconjug Chem 2009; 20:1383-9. [PMID: 19507852 PMCID: PMC3402211 DOI: 10.1021/bc900149r] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
For multiple site-specific conjugations of bioactive molecules to a single-chain antibody (scFv) molecule, we have constructed a human anti HER2 receptor, scFv, with a C-terminal fusion polypeptide containing 1, 3, or 17 threonine (Thr) residues. The C-terminal extended fusion polypeptides of these recombinant scFv fusion proteins are used as the acceptor substrate for human polypeptide-alpha-Nu-acetylgalactosaminyltransferase II (h-ppGalNAc-T2) that transfers either GalNAc or 2-keto-Gal, a modified galactose with a chemical handle, from their respective UDP-sugars to the side-chain hydroxyl group of the Thr residue(s). The recombinant scFv fusion proteins are expressed in E. coli as inclusion bodies and in vitro refolded and glycosylated with h-ppGalNAc-T2. Upon protease cleavage, the MALDI-TOF spectra of the glycosylated C-terminal fusion polypeptides showed that the glycosylated scFv fusion protein with a single Thr residue is fully glycosylated with a single 2-keto-Gal, whereas the glycosylated scFv fusion protein with 3 and 17 Thr residues is found as an equal mixture of 2-3 and 5-8 2-keto-Gal glycosylated fusion proteins, respectively. These fusion scFv proteins with the modified galactose are then conjugated with a fluorescence probe, Alexa488, that carries an orthogonal reactive group. The fluorescence labeled scFv proteins bind specifically to a human breast cancer cell line (SK-BR-3) that overexpresses the HER2 receptor, indicating that the in vitro folded scFv fusion proteins are biologically active and the presence of conjugated multiple Alexa488 probes in their C-terminal end does not interfere with their binding to the antigen.
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Affiliation(s)
| | | | | | | | | | | | | | - Pradman K. Qasba
- Corresponding author. Structural Glycobiology Section, CCRNP, CCR, NCI-Frederick, Building 469, Room 221, Frederick, Maryland 21702; . Phone: (301) 846-1934; Fax: (301) 846-7149
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Qasba PK, Ramakrishnan B, Boeggeman E. Structure and function of beta -1,4-galactosyltransferase. Curr Drug Targets 2008; 9:292-309. [PMID: 18393823 DOI: 10.2174/138945008783954943] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Beta-1,4-galactosylransferase (beta4Gal-T1) participates in the synthesis of Galbeta1-4-GlcNAc-disaccharide unit of glycoconjugates. It is a trans-Golgi glycosyltransferase (Glyco-T) with a type II membrane protein topology, a short N-terminal cytoplasmic domain, a membrane-spanning region, as well as a stem and a C-terminal catalytic domain facing the trans-Golgi-lumen. Its hydrophobic membrane-spanning region, like that of other Glyco-T, has a shorter length compared to plasma membrane proteins, an important feature for its retention in the trans-Golgi. The catalytic domain has two flexible loops, a long and a small one. The primary metal binding site is located at the N-terminal hinge region of the long flexible loop. Upon binding of metal ion and sugar-nucleotide, the flexible loops undergo a marked conformational change, from an open to a closed conformation. Conformational change simultaneously creates at the C-terminal region of the flexible loop an oligosaccharide acceptor binding site that did not exist before. The loop acts as a lid covering the bound donor substrate. After completion of the transfer of the glycosyl unit to the acceptor, the saccharide product is ejected; the loop reverts to its native conformation to release the remaining nucleotide moiety. The conformational change in beta4Gal-T1 also creates the binding site for a mammary gland-specific protein, alpha-lactalbumin (LA), which changes the acceptor specificity of the enzyme toward glucose to synthesize lactose during lactation. The specificity of the sugar donor is generally determined by a few residues in the sugar-nucleotide binding pocket of Glyco-T, conserved among the family members from different species. Mutation of these residues has allowed us to design new and novel glycosyltransferases, with broader or requisite donor and acceptor specificities, and to synthesize specific complex carbohydrates as well as specific inhibitors for these enzymes.
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Affiliation(s)
- Pradman K Qasba
- Structural Glycobiology Section, CCRNP, NCI-Frederick, Building 469, Room 221, Frederick, Maryland 21702, USA.
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Characterization of recombinant fusion constructs of human β1,4-galactosyltransferase 1 and the lipase pre-propeptide from Staphylococcus hyicus. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.molcatb.2007.09.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Ramakrishnan B, Boeggeman E, Qasba PK. Novel method for in vitro O-glycosylation of proteins: application for bioconjugation. Bioconjug Chem 2007; 18:1912-8. [PMID: 17953440 DOI: 10.1021/bc7002346] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Here, we describe a new method for the bioconjugation of a nonglycoprotein with biomolecules. Using polypeptide-alpha- N-acetylgalactosaminyltransferase II (ppGalNAc-T2), we transfer a C2-modified galactose that has a chemical handle, such as ketone or azide, from its respective UDP-sugars to the Ser/Thr residue(s) of an acceptor polypeptide fused to the nonglycoprotein. The protein with the modified galactose is then coupled to a biomolecule that carries an orthogonal reactive group. As a model system for the nonglycoprotein, we engineered glutathione- S-transferase (GST) protein with a 17-amino-acid-long fusion peptide at the C-terminal end that was expressed as a soluble protein in E. coli. The ppGalNAc-T2 protein, the catalytic domain with the C-terminal lectin domain, was expressed as inclusion bodies in E. coli, and an in vitro folding method was developed to produce milligram quantities of the active enzyme from a liter of bacterial culture. This ppGalNAc-T2 enzyme transfers from the UDP-sugars not only GalNAc but also C2-modified galactose with a chemical handle to the Ser/Thr residue(s) in the fusion peptide. The chemical handle at the C2 of galactose is used for conjugation and assembly of bionanoparticles and preparation of immuno-liposomes for a targeted drug delivery system. This novel method enables one to glycosylate, using ppGalNAc-T2, the important biological nonglycoproteins, such as single-chain antibodies, growth factors, or bacterial toxins, with an engineered 17-residue peptide sequence at the C-terminus of the molecule, for conjugation and coupling.
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Affiliation(s)
- Boopathy Ramakrishnan
- Structural Glycobiology Section, and Basic Research Program, SAIC-Frederick Inc, Center for Cancer Research Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, MD 21702 , USA
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Madan LL, Gopal B. Addition of a polypeptide stretch at the N-terminus improves the expression, stability and solubility of recombinant protein tyrosine phosphatases from Drosophila melanogaster. Protein Expr Purif 2007; 57:234-43. [PMID: 18023205 DOI: 10.1016/j.pep.2007.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 10/01/2007] [Accepted: 10/03/2007] [Indexed: 01/09/2023]
Abstract
The production of recombinant proteins in Escherichia coli involves substantial optimization in the size of the protein and over-expression strategies to avoid inclusion-body formation. Here we report our observations on this so-called construct dependence using the catalytic domains of five Drosophila melanogaster receptor protein tyrosine phosphatases as a model system. Five strains of E. coli as well as three variations in purification tags viz., poly-histidine peptide attachments at the N- and C-termini and a construct with Glutathione-S-transferase at the N-terminus were examined. In this study we observe that inclusion of a 45 residue stretch at the N-terminus was crucial for over-expression of the enzymes, influencing both the solubility and the stability of these recombinant proteins. While the addition of negatively charged residues in the N-terminal extension could partially rationalize the improvement in the solubility of these constructs, conventional parameters like the proportion of order promoting residues or aliphatic index did not correlate with the improved biochemical characteristics. These findings thus suggest the inclusion of additional parameters apart from rigid domain predictions to obtain domain constructs that are most likely to yield soluble protein upon expression in E. coli.
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Affiliation(s)
- Lalima L Madan
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
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Boeggeman E, Ramakrishnan B, Kilgore C, Khidekel N, Hsieh-Wilson LC, Simpson JT, Qasba PK. Direct identification of nonreducing GlcNAc residues on N-glycans of glycoproteins using a novel chemoenzymatic method. Bioconjug Chem 2007; 18:806-14. [PMID: 17370997 PMCID: PMC3534963 DOI: 10.1021/bc060341n] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The mutant beta1,4-galactosyltransferase (beta4Gal-T1), beta4Gal-T1-Y289L, in contrast to wild-type beta4Gal-T1, can transfer GalNAc from the sugar donor UDP-GalNAc to the acceptor, GlcNAc, with efficiency as good as that of galactose from UDP-Gal. Furthermore, the mutant can also transfer a modified sugar, C2 keto galactose, from its UDP derivative to O-GlcNAc modification on proteins that provided a functional handle for developing a highly sensitive chemoenzymatic method for detecting O-GlcNAc post-translational modification on proteins. We report herein that the modified sugar, C2 keto galactose, can be transferred to free GlcNAc residues on N-linked glycoproteins, such as ovalbumin or asialo-agalacto IgG1. The transfer is strictly dependent on the presence of both the mutant enzyme and the ketone derivative of the galactose. Moreover, the PNGase F treatment of the glycoproteins, which cleaves the N-linked oligosaccharide chain, shows that the modified sugar has been transferred to the N-glycan chains of the glycoproteins and not to the protein portion. The application of the mutant galactosyltransferase, beta4Gal-T1-Y289L, to produce glycoconjugates carrying sugar moieties with reactive groups, is demonstrated. We envision a broad potential for this technology such as the possibilities to link cargo molecules to glycoproteins, such as monoclonal antibodies, via glycan chains, thereby assisting in the glycotargeting of drugs to the site of action or used as biological probes.
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Affiliation(s)
- Elizabeth Boeggeman
- Structural Glycobiology Section, CCR-Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, Maryland 21702
- SAIC-Inc. NCI-Frederick, Frederick, Maryland 21702
| | - Boopathy Ramakrishnan
- Structural Glycobiology Section, CCR-Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, Maryland 21702
- SAIC-Inc. NCI-Frederick, Frederick, Maryland 21702
| | - Charlton Kilgore
- Structural Glycobiology Section, CCR-Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, Maryland 21702
| | - Nelly Khidekel
- Division of Chemistry and Chemical Engineering and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, California 91125
| | - Linda C. Hsieh-Wilson
- Division of Chemistry and Chemical Engineering and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, California 91125
| | - John T. Simpson
- Protein Chemistry Laboratory, SAIC-Inc. NCI-Frederick, Frederick, Maryland 21702
| | - Pradman K. Qasba
- Structural Glycobiology Section, CCR-Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, Maryland 21702
- Corresponding author: Structural Glycobiology Section, CCR, Nanobiology Program, NCI-Frederick, Building 469, Room 221, Frederick, Maryland 21702. . Phone: (301) 846-1934. Fax: (301) 846-7149
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Ramakrishnan B, Qasba PK. Role of a single amino acid in the evolution of glycans of invertebrates and vertebrates. J Mol Biol 2007; 365:570-6. [PMID: 17084860 PMCID: PMC1850938 DOI: 10.1016/j.jmb.2006.10.034] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Revised: 10/09/2006] [Accepted: 10/10/2006] [Indexed: 11/25/2022]
Abstract
Structures of glycoconjugate N-glycans and glycolipids of invertebrates show significant differences from those of vertebrates. These differences are due largely to the vertebrate beta1,4-galactosyltransferase-1 (beta4Gal-T1), which is found as a beta1,4-N-acetylgalactosaminyltransferase (beta4GalNAc-T1) in invertebrates. Mutation of Tyr285 to Ile or Leu in human beta4Gal-T1 converts the enzyme into an equally efficient beta4GalNAc-T1. A comparison of all the human beta4Gal-T1 ortholog enzymes shows that this Tyr285 residue in human beta4Gal-T1 is conserved either as Tyr or Phe in all vertebrate enzymes, while in all invertebrate enzymes it is conserved as an Ile or Leu. We find that mutation of the corresponding Ile residue to Tyr in Drosophila beta4GalNAc-T1 converts the enzyme to a beta4Gal-T1 by reducing its N-acetylgalactosaminyltransferase activity by nearly 1000-fold, while enhancing its galactosyltransferase activity by 80-fold. Furthermore, we find that, similar to the vertebrate/mammalian beta4Gal-T1 enzymes, the wild-type Drosophila beta4GalNAc-T1 enzyme binds to a mammary gland-specific protein, alpha-lactalbumin (alpha-LA). Thus, it would seem that, during the evolution of vertebrates from invertebrates over 500 million years ago, beta4Gal-T1 appeared as a result of the single amino acid substitution of Tyr or Phe for Leu or Ile in the invertebrate beta4GalNAc-T1. Subsequently, the pre-existing alpha-LA-binding site was utilized during mammalian evolution to synthesize lactose in the mammary gland during lactation.
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Affiliation(s)
- Boopathy Ramakrishnan
- Structural Glycobiology Section§, CCR Nanobiology Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD
- Basic Research Program¶, SAIC-Frederick, Inc., Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD
| | - Pradman K. Qasba
- Structural Glycobiology Section§, CCR Nanobiology Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD
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Ju T, Zheng Q, Cummings RD. Identification of core 1 O-glycan T-synthase from Caenorhabditis elegans. Glycobiology 2006; 16:947-58. [PMID: 16762980 DOI: 10.1093/glycob/cwl008] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The common O-glycan core structure in animal glycoproteins is the core 1 disaccharide Galbeta1-3GalNAcalpha1-Ser/Thr, which is generated by the addition of Gal to GalNAcalpha1-Ser/Thr by core 1 UDP-alpha-galactose (UDP-Gal):GalNAcalpha1-Ser/Thr beta1,3-galactosyltransferase (core 1 beta3-Gal-T or T-synthase, EC2.4.1.122). Although O-glycans play important roles in vertebrates, much remains to be learned from model organisms such as the free-living nematode Caenorhabditis elegans, which offer many advantages in exploring O-glycan structure/function. Here, we report the cloning and enzymatic characterization of T-synthase from C. elegans (Ce-T-synthase). A putative C. elegans gene for T-synthase, C38H2.2, was identified in GenBank by a BlastP search using the human T-synthase protein sequence. The full-length cDNA for Ce-T-synthase, which was generated by polymerase chain reaction using a C. elegans cDNA library as the template, contains 1170 bp including the stop TAA. The cDNA encodes a protein of 389 amino acids with typical type II membrane topology and a remarkable 42.7% identity to the human T-synthase. Ce-T-synthase has seven Cys residues in the lumenal domain including six conserved Cys residues in all orthologs. The Ce-T-synthase has four potential N-glycosylation sequons, whereas the mammalian orthologs lack N-glycosylation sequons. Only one gene for Ce-T-synthase was identified in the genome-wide search, and it contains eight exons. Promoter analysis of the Ce-T-synthase using green fluorescent protein (GFP) constructs shows that the gene is expressed at all developmental stages and appears to be in all cells. Unexpectedly, only minimal activity was recovered in the recombinant, soluble Ce-T-synthase secreted from a wide variety of mammalian cell lines, whereas robust enzyme activity was recovered in the soluble Ce-T-synthase expressed in Hi-5 insect cells. Vertebrate T-synthase requires the molecular chaperone Cosmc, but our results show that Ce-T-synthase does not require Cosmc and might require invertebrate-specific factors for the formation of the optimally active enzyme. These results show that the Ce-T-synthase is a functional ortholog to the human T-synthase in generating core 1 O-glycans and open new avenues to explore O-glycan function in this model organism.
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Affiliation(s)
- Tongzhong Ju
- Department of Biochemistry and Molecular Biology, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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31
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Lattard V, Fondeur-Gelinotte M, Gulberti S, Jacquinet JC, Boudrant J, Netter P, Magdalou J, Ouzzine M, Fournel-Gigleux S. Purification and characterization of a soluble form of the recombinant human galactose-beta1,3-glucuronosyltransferase I expressed in the yeast Pichia pastoris. Protein Expr Purif 2005; 47:137-43. [PMID: 16300963 DOI: 10.1016/j.pep.2005.10.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2005] [Revised: 10/07/2005] [Accepted: 10/07/2005] [Indexed: 11/20/2022]
Abstract
The galactose-beta1,3-glucuronosyltransferase I (GlcAT-I) catalyzes the transfer of glucuronic acid from UDP-alpha-D-glucuronic acid onto the terminal galactose of the trisaccharide glycosaminoglycan-protein linker region of proteoglycans. This enzyme plays a key role in the process of proteoglycan assembly since the completion of the linkage region is essential for the conversion of a core protein into a functional proteoglycan. To investigate the enzymatic properties of human GlcAT-I, we established an expression system for producing a soluble form of enzyme in the methylotrophic yeast Pichia pastoris and developed a three-step purification procedure using a combination of anion exchange, cation exchange and heparin chromatographies. This procedure yielded 1.6 mg homogeneous enzyme from 200 ml yeast cell culture, with a specific activity value of 1.5 micromol/min/mg protein. Analysis of the specificity of GlcAT-I towards Galbeta1-3Gal and Galbeta1-4GlcNAc derivatives known as substrates of the beta1,3-glucuronosyltransferases, showed that the enzyme exhibited a strict selectivity towards Galbeta1-3Gal structures. Thus, the large source of purified active enzyme allowed the determination of the kinetic parameters of GlcAT-I towards the donor substrate UDP-GlcA and the acceptor substrate digalactoside Galbeta1-3Gal.
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Affiliation(s)
- Virginie Lattard
- UMR 7561 CNRS-Université Henri Poincaré Nancy I, Faculté de Médecine, BP 184, 54505 Vandoeuvre-lès-Nancy Cedex, France
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Idicula-Thomas S, Balaji PV. Understanding the relationship between the primary structure of proteins and its propensity to be soluble on overexpression in Escherichia coli. Protein Sci 2005; 14:582-92. [PMID: 15689506 PMCID: PMC2279285 DOI: 10.1110/ps.041009005] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Solubility of proteins on overexpression in Escherichia coli is a manifestation of the net effect of several sequence-dependent and sequence-independent factors. This study aims to delineate the relationship between the primary structure and solubility on overexpression. The amino acid sequences of proteins reported to be soluble or to form inclusion bodies on overexpression in E. coli under normal growth conditions were analyzed. The results show a positive correlation between thermostability and solubility of proteins, and an inverse correlation between the in vivo half-life of proteins and solubility. The amino acid (Asn, Thr, Tyr) composition and the tripeptide frequency of the protein were also found to influence its solubility on overexpression. The amino acids that were seen to be present in a comparatively higher frequency in inclusion body-forming proteins have a higher sheet propensity, whereas those that are seen more in soluble proteins have a higher helix propensity; this is indicative of a possible correlation between sheet propensity and inclusion body formation. Thus, the present analysis shows that thermostability, in vivo half-life, Asn, Thr, and Tyr content, and tripeptide composition of a protein are correlated to the propensity of a protein to be soluble on overexpression in E. coli. The precise mechanism by which these properties affect the solubility status of the overexpressed protein remains to be understood.
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Affiliation(s)
- Susan Idicula-Thomas
- School of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
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Choudhary RK, Pullakhandam R, Ehtesham NZ, Hasnain SE. Expression and characterization of Rv2430c, a novel immunodominant antigen of Mycobacterium tuberculosis. Protein Expr Purif 2004; 36:249-53. [PMID: 15249047 DOI: 10.1016/j.pep.2004.03.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2004] [Revised: 03/02/2004] [Indexed: 11/18/2022]
Abstract
About 10% of the coding sequence of Mycobacterium tuberculosis corresponds to hitherto unknown members of the PE and PPE protein families which display significant sequence and length variation at their C-terminal region. It has been suggested that this could possibly represent a rich source of antigenic variation within the pathogen. We describe the purification and biophysical characterization of the recombinant PPE protein coded by hypothetical ORF Rv2430c, a member of the PPE gene family that was earlier shown to induce a strong B cell response. Expression of the recombinant PPE protein in Escherichia coli led to its localization in inclusion bodies and subsequent refolding using dialysis after its extraction from the same resulted in extensive precipitation. Therefore, an on-column refolding strategy was used, after which the protein was found to be in the soluble form. CD spectrum of the recombinant protein displayed predominantly alpha helical content (81%) which matched significantly with in silico and web-based secondary structure predictions. Furthermore, fluorescence emission spectra revealed that aromatic amino acids are buried inside the protein, which are exposed to aqueous environment under 8M urea. These results, for the first time, provide evidence on the structural features of PPE family protein which, viewed with its reported immunodominant characteristics, have implications for other proteins of the PE/PPE family.
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