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Nguyen KD, Kajiura H, Kamiya R, Yoshida T, Misaki R, Fujiyama K. Production and N-glycan engineering of Varlilumab in Nicotiana benthamiana. FRONTIERS IN PLANT SCIENCE 2023; 14:1215580. [PMID: 37615027 PMCID: PMC10442953 DOI: 10.3389/fpls.2023.1215580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 07/03/2023] [Indexed: 08/25/2023]
Abstract
N-glycan engineering has dramatically evolved for the development and quality control of recombinant antibodies. Fc region of IgG contains two N-glycans whose galactose terminals on Fc-glycan have been shown to increase the stability of CH2 domain and improve effector functions. Nicotiana benthamiana has become one of the most attractive production systems for therapeutic antibodies. In this study, Varlilumab, a CD27-targeting monoclonal antibody, was transiently produced in fresh leaves of soil-grown and hydroponic-grown N. benthamiana, resulted in the yield of 174 and 618 µg/gram, respectively. However, the IgG produced in wild-type N. benthamiana lacked the terminal galactose residues in its N-glycan. Therefore, N-glycan engineering was applied to fine-tune recombinant antibodies produced in plant platforms. We further co-expressed IgG together with murine β1,4-galactosyltransferase (β1,4-GALT) to modify plant N-glycan with β1,4-linked Gal residue(s) and Arabidopsis thaliana β1,3-galactosylatransferase (β1,3-GALT) to improve galactosylation. The co-expression of IgG with each of GALTs successfully resulted in modification of N-glycan structures on the plant-produced IgG. Notably, IgG co-expressed with murine β1,4-GALT in soil-grown N. benthamiana had 42.5% of N-glycans variants having galactose (Gal) residues at the non-reducing terminus and 55.3% of that in hydroponic-grown N. benthamiana plants. Concomitantly, N-glycan profile analysis of IgG co-expressed with β1,3-GALT demonstrated that there was an increased efficiency of galactosylation and an enhancement in the formation of Lewis a structure in plant-derived antibodies. Taken together, our findings show that the first plant-derived Varlilumab was successfully produced with biantennary β1,4-galactosylated N-glycan structures.
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Affiliation(s)
- Kim Dua Nguyen
- International Center for Biotechnology, Osaka University, Osaka, Japan
| | - Hiroyuki Kajiura
- International Center for Biotechnology, Osaka University, Osaka, Japan
- Industrial Biotechnology Initiative Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Osaka, Japan
| | - Ryo Kamiya
- GreenLand-Kidaya Group Co Ltd., Fukui, Japan
| | | | - Ryo Misaki
- International Center for Biotechnology, Osaka University, Osaka, Japan
- Industrial Biotechnology Initiative Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Osaka, Japan
| | - Kazuhito Fujiyama
- International Center for Biotechnology, Osaka University, Osaka, Japan
- Industrial Biotechnology Initiative Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Osaka, Japan
- Osaka University Cooperative Research Station in Southeast Asia (OU: CRS), Faculty of Science, Mahidol University, Bangkok, Thailand
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van der Kaaij A, van Noort K, Nibbering P, Wilbers RHP, Schots A. Glyco-Engineering Plants to Produce Helminth Glycoproteins as Prospective Biopharmaceuticals: Recent Advances, Challenges and Future Prospects. FRONTIERS IN PLANT SCIENCE 2022; 13:882835. [PMID: 35574113 PMCID: PMC9100689 DOI: 10.3389/fpls.2022.882835] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 03/28/2022] [Indexed: 06/15/2023]
Abstract
Glycoproteins are the dominant category among approved biopharmaceuticals, indicating their importance as therapeutic proteins. Glycoproteins are decorated with carbohydrate structures (or glycans) in a process called glycosylation. Glycosylation is a post-translational modification that is present in all kingdoms of life, albeit with differences in core modifications, terminal glycan structures, and incorporation of different sugar residues. Glycans play pivotal roles in many biological processes and can impact the efficacy of therapeutic glycoproteins. The majority of biopharmaceuticals are based on human glycoproteins, but non-human glycoproteins, originating from for instance parasitic worms (helminths), form an untapped pool of potential therapeutics for immune-related diseases and vaccine candidates. The production of sufficient quantities of correctly glycosylated putative therapeutic helminth proteins is often challenging and requires extensive engineering of the glycosylation pathway. Therefore, a flexible glycoprotein production system is required that allows straightforward introduction of heterologous glycosylation machinery composed of glycosyltransferases and glycosidases to obtain desired glycan structures. The glycome of plants creates an ideal starting point for N- and O-glyco-engineering of helminth glycans. Plants are also tolerant toward the introduction of heterologous glycosylation enzymes as well as the obtained glycans. Thus, a potent production platform emerges that enables the production of recombinant helminth proteins with unusual glycans. In this review, we discuss recent advances in plant glyco-engineering of potentially therapeutic helminth glycoproteins, challenges and their future prospects.
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Bohlender LL, Parsons J, Hoernstein SNW, Bangert N, Rodríguez-Jahnke F, Reski R, Decker EL. Unexpected Arabinosylation after Humanization of Plant Protein N-Glycosylation. Front Bioeng Biotechnol 2022; 10:838365. [PMID: 35252146 PMCID: PMC8894861 DOI: 10.3389/fbioe.2022.838365] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/28/2022] [Indexed: 02/03/2023] Open
Abstract
As biopharmaceuticals, recombinant proteins have become indispensable tools in medicine. An increasing demand, not only in quantity but also in diversity, drives the constant development and improvement of production platforms. The N-glycosylation pattern on biopharmaceuticals plays an important role in activity, serum half-life and immunogenicity. Therefore, production platforms with tailored protein N-glycosylation are of great interest. Plant-based systems have already demonstrated their potential to produce pharmaceutically relevant recombinant proteins, although their N-glycan patterns differ from those in humans. Plants have shown great plasticity towards the manipulation of their glycosylation machinery, and some have already been glyco-engineered in order to avoid the attachment of plant-typical, putatively immunogenic sugar residues. This resulted in complex-type N-glycans with a core structure identical to the human one. Compared to humans, plants lack the ability to elongate these N-glycans with β1,4-linked galactoses and terminal sialic acids. However, these modifications, which require the activity of several mammalian enzymes, have already been achieved for Nicotiana benthamiana and the moss Physcomitrella. Here, we present the first step towards sialylation of recombinant glycoproteins in Physcomitrella, human β1,4-linked terminal N-glycan galactosylation, which was achieved by the introduction of a chimeric β1,4-galactosyltransferase (FTGT). This chimeric enzyme consists of the moss α1,4-fucosyltransferase transmembrane domain, fused to the catalytic domain of the human β1,4-galactosyltransferase. Stable FTGT expression led to the desired β1,4-galactosylation. However, additional pentoses of unknown identity were also observed. The nature of these pentoses was subsequently determined by Western blot and enzymatic digestion followed by mass spectrometric analysis and resulted in their identification as α-linked arabinoses. Since a pentosylation of β1,4-galactosylated N-glycans was reported earlier, e.g., on recombinant human erythropoietin produced in glyco-engineered Nicotiana tabacum, this phenomenon is of a more general importance for plant-based production platforms. Arabinoses, which are absent in humans, may prevent the full humanization of plant-derived products. Therefore, the identification of these pentoses as arabinoses is important as it creates the basis for their abolishment to ensure the production of safe biopharmaceuticals in plant-based systems.
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Affiliation(s)
- Lennard L. Bohlender
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Juliana Parsons
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - Nina Bangert
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Fernando Rodríguez-Jahnke
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany
| | - Ralf Reski
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Eva L. Decker
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
- *Correspondence: Eva L. Decker,
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Bohlender LL, Parsons J, Hoernstein SNW, Rempfer C, Ruiz-Molina N, Lorenz T, Rodríguez Jahnke F, Figl R, Fode B, Altmann F, Reski R, Decker EL. Stable Protein Sialylation in Physcomitrella. FRONTIERS IN PLANT SCIENCE 2020; 11:610032. [PMID: 33391325 PMCID: PMC7775405 DOI: 10.3389/fpls.2020.610032] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 11/30/2020] [Indexed: 05/07/2023]
Abstract
Recombinantly produced proteins are indispensable tools for medical applications. Since the majority of them are glycoproteins, their N-glycosylation profiles are major determinants for their activity, structural properties and safety. For therapeutical applications, a glycosylation pattern adapted to product and treatment requirements is advantageous. Physcomitrium patens (Physcomitrella, moss) is able to perform highly homogeneous complex-type N-glycosylation. Additionally, it has been glyco-engineered to eliminate plant-specific sugar residues by knock-out of the β1,2-xylosyltransferase and α1,3-fucosyltransferase genes (Δxt/ft). Furthermore, Physcomitrella meets wide-ranging biopharmaceutical requirements such as GMP compliance, product safety, scalability and outstanding possibilities for precise genome engineering. However, all plants, in contrast to mammals, lack the capability to perform N-glycan sialylation. Since sialic acids are a common terminal modification on human N-glycans, the property to perform N-glycan sialylation is highly desired within the plant-based biopharmaceutical sector. In this study, we present the successful achievement of protein N-glycan sialylation in stably transformed Physcomitrella. The sialylation ability was achieved in a Δxt/ft moss line by stable expression of seven mammalian coding sequences combined with targeted organelle-specific localization of the encoded enzymes responsible for the generation of β1,4-galactosylated acceptor N-glycans as well as the synthesis, activation, transport and transfer of sialic acid. Production of free (Neu5Ac) and activated (CMP-Neu5Ac) sialic acid was proven. The glycosidic anchor for the attachment of terminal sialic acid was generated by the introduction of a chimeric human β1,4-galactosyltransferase gene under the simultaneous knock-out of the gene encoding the endogenous β1,3-galactosyltransferase. Functional complex-type N-glycan sialylation was confirmed via mass spectrometric analysis of a stably co-expressed recombinant human protein.
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Affiliation(s)
- Lennard L. Bohlender
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Juliana Parsons
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - Christine Rempfer
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg, Germany
| | - Natalia Ruiz-Molina
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Timo Lorenz
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Fernando Rodríguez Jahnke
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg, Germany
| | - Rudolf Figl
- Department of Chemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | | | - Friedrich Altmann
- Department of Chemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Ralf Reski
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
- Cluster of Excellence livMatS, Freiburg Center for Interactive Materials and Bioinspired Technologies, University of Freiburg, Freiburg, Germany
| | - Eva L. Decker
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
- *Correspondence: Eva L. Decker,
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Schiermeyer A. Optimizing product quality in molecular farming. Curr Opin Biotechnol 2019; 61:15-20. [PMID: 31593785 DOI: 10.1016/j.copbio.2019.08.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 08/23/2019] [Accepted: 08/26/2019] [Indexed: 12/28/2022]
Abstract
The production of biopharmaceuticals in plant-based systems had faced several challenges that hampered broader adoption of this technology. In recent years, various plant production hosts have been improved by genetic engineering approaches to overcome obstacles with regard to post-translational modifications and integrity of target proteins. Together with optimized extraction and purification processes, those advances have put plant molecular farming in a more competitive position compared to established production systems. Certain biopharmaceuticals can be derived from plant systems with unique desired properties, qualifying them as biobetters.
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Affiliation(s)
- Andreas Schiermeyer
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Forckenbeckstrasse 6, 52074, Aachen, Germany.
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Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2013-2014. MASS SPECTROMETRY REVIEWS 2018; 37:353-491. [PMID: 29687922 DOI: 10.1002/mas.21530] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 11/29/2016] [Indexed: 06/08/2023]
Abstract
This review is the eighth update of the original article published in 1999 on the application of Matrix-assisted laser desorption/ionization mass spectrometry (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2014. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, and arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly- saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2018 Wiley Periodicals, Inc. Mass Spec Rev 37:353-491, 2018.
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Affiliation(s)
- David J Harvey
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7FZ, United Kingdom
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7
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Navarre C, Smargiasso N, Duvivier L, Nader J, Far J, De Pauw E, Boutry M. N-Glycosylation of an IgG antibody secreted by Nicotiana tabacum BY-2 cells can be modulated through co-expression of human β-1,4-galactosyltransferase. Transgenic Res 2017; 26:375-384. [PMID: 28332009 DOI: 10.1007/s11248-017-0013-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 02/28/2017] [Indexed: 12/12/2022]
Abstract
Nicotiana tabacum BY-2 suspension cells have several advantages that make them suitable for the production of full-size monoclonal antibodies which can be purified directly from the culture medium. Carbohydrate characterization of an antibody (Lo-BM2) expressed in N. tabacum BY-2 cells showed that the purified Lo-BM2 displays N-glycan homogeneity with a high proportion (>70%) of the complex GnGnXF glycoform. The stable co-expression of a human β-1,4-galactosyltransferase targeted to different Golgi sub-compartments altered Lo-BM2N-glycosylation and resulted in the production of an antibody that exhibited either hybrid structures containing a low abundance of the plant epitopes (α-1,3-fucose and β-1,2-xylose), or a large amount of galactose-extended N-glycan structures. These results demonstrate the suitability of stable N-glycoengineered N. tabacum BY-2 cell lines for the production of human-like antibodies.
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Affiliation(s)
- Catherine Navarre
- Institut des Sciences de la Vie, Université catholique de Louvain, 1348, Louvain-la-Neuve, Belgium.
| | | | - Laurent Duvivier
- Institut des Sciences de la Vie, Université catholique de Louvain, 1348, Louvain-la-Neuve, Belgium
| | - Joseph Nader
- Institut des Sciences de la Vie, Université catholique de Louvain, 1348, Louvain-la-Neuve, Belgium
| | - Johann Far
- Mass Spectrometry Laboratory, University of Liege, 4000, Liège, Belgium
| | - Edwin De Pauw
- Mass Spectrometry Laboratory, University of Liege, 4000, Liège, Belgium
| | - Marc Boutry
- Institut des Sciences de la Vie, Université catholique de Louvain, 1348, Louvain-la-Neuve, Belgium
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Wilbers RHP, Westerhof LB, van Noort K, Obieglo K, Driessen NN, Everts B, Gringhuis SI, Schramm G, Goverse A, Smant G, Bakker J, Smits HH, Yazdanbakhsh M, Schots A, Hokke CH. Production and glyco-engineering of immunomodulatory helminth glycoproteins in plants. Sci Rep 2017; 7:45910. [PMID: 28393916 PMCID: PMC5385521 DOI: 10.1038/srep45910] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 03/03/2017] [Indexed: 01/15/2023] Open
Abstract
Helminth parasites control host-immune responses by secreting immunomodulatory glycoproteins. Clinical trials and mouse model studies have demonstrated the potential of helminth-derived glycoproteins for the treatment of immune-related diseases, like allergies and autoimmune diseases. Studies are however hampered by the limited availability of native parasite-derived proteins. Moreover, recombinant protein production systems have thus far been unable to reconstitute helminth-like glycosylation essential for the functionality of some helminth glycoproteins. Here we exploited the flexibility of the N-glycosylation machinery of plants to reconstruct the helminth glycoproteins omega-1 and kappa-5, two major constituents of immunomodulatory Schistosoma mansoni soluble egg antigens. Fine-tuning transient co-expression of specific glycosyltransferases in Nicotiana benthamiana enabled the synthesis of Lewis X (LeX) and LDN/LDN-F glycan motifs as found on natural omega-1 and kappa-5, respectively. In vitro and in vivo evaluation of the introduction of native LeX motifs on plant-produced omega-1 confirmed that LeX on omega-1 contributes to the glycoprotein's Th2-inducing properties. These data indicate that mimicking the complex carbohydrate structures of helminths in plants is a promising strategy to allow targeted evaluation of therapeutic glycoproteins for the treatment of inflammatory disorders. In addition, our results offer perspectives for the development of effective anti-helminthic vaccines by reconstructing native parasite glycoprotein antigens.
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Affiliation(s)
- Ruud H. P. Wilbers
- Laboratory of Nematology, Plant Sciences Group, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Lotte B. Westerhof
- Laboratory of Nematology, Plant Sciences Group, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Kim van Noort
- Laboratory of Nematology, Plant Sciences Group, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Katja Obieglo
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Nicole N. Driessen
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Bart Everts
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Sonja I. Gringhuis
- Department of Experimental Immunology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Gabriele Schramm
- Research Center Borstel, Priority Area Asthma and Allergy, Experimental Pneumology, Parkallee 22, D-23845, Borstel, Germany
| | - Aska Goverse
- Laboratory of Nematology, Plant Sciences Group, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Geert Smant
- Laboratory of Nematology, Plant Sciences Group, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Jaap Bakker
- Laboratory of Nematology, Plant Sciences Group, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Hermelijn H. Smits
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Maria Yazdanbakhsh
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Arjen Schots
- Laboratory of Nematology, Plant Sciences Group, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Cornelis H. Hokke
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
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Geisler C, Mabashi-Asazuma H, Kuo CW, Khoo KH, Jarvis DL. Engineering β1,4-galactosyltransferase I to reduce secretion and enhance N-glycan elongation in insect cells. J Biotechnol 2014; 193:52-65. [PMID: 25462875 DOI: 10.1016/j.jbiotec.2014.11.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 11/12/2014] [Accepted: 11/17/2014] [Indexed: 12/13/2022]
Abstract
β1,4-galactosyltransferase I (B4GALT1) is a Golgi-resident enzyme that elongates glycoprotein glycans, but a subpopulation of this enzyme is secreted following proteolytic cleavage in its stem domain. We hypothesized that engineering B4GALT1 to block cleavage and secretion would enhance its retention and, therefore, its function. To test this hypothesis, we replaced the cytoplasmic/transmembrane/stem (CTS) domains of B4GALT1 with those from human α1,3-fucosyltransferase 7 (FUT7), which is not cleaved and secreted. Expression of FUT7-CTS-B4GALT1 in insect cells produced lower levels of secreted and higher levels of intracellular B4GALT1 activity than the native enzyme. We also noted that the B4GALT1 used in our study had a leucine at position 282, whereas all other animal B4GALT1 sequences have an aromatic amino acid at this position. Thus, we examined the combined impact of changing the CTS domains and the amino acid at position 282 on intracellular B4GALT1 activity levels and N-glycan processing in insect cells. The results demonstrated a correlation between the levels of intracellular B4GALT1 activity and terminally galactosylated N-glycans, N-glycan branching, the appearance of hybrid structures, and reduced core fucosylation. Thus, engineering B4GALT1 to reduce its cleavage and secretion is an approach that can be used to enhance N-glycan elongation in insect cells.
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Affiliation(s)
- Christoph Geisler
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA; GlycoBac, LLC, Laramie, WY 82072, USA
| | | | - Chu-Wei Kuo
- Institute of Biological Chemistry, Academia Sinica 128, Nankang, Taipei 115, Taiwan
| | - Kay-Hooi Khoo
- Institute of Biological Chemistry, Academia Sinica 128, Nankang, Taipei 115, Taiwan
| | - Donald L Jarvis
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA; GlycoBac, LLC, Laramie, WY 82072, USA.
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