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Abstract
While antibody libraries are traditionally screened in phage, bacterial, or yeast display formats, they are produced in large scale for pharmaceutical and commercial use in mammalian cell lines. The simpler organisms used for screening have significantly different folding and glycosylation machinery than mammalian cells; consequently, clones resulting from these libraries may require further optimization for mammalian cell expression. To streamline the antibody discovery process, we developed a Chinese hamster ovary (CHO) cell-based selection system that allows for long-term display of antibody Fab fragments. This system is facilitated by a semi-stable Epi-CHO episomal platform to maintain antibody expression for up to 2 months and is compatible with standard PCR-based mutagenesis strategies. This protocol describes the simple and accessible use of CHO display coupled with flow cytometry to enrich for antibody variants with increased ligand-binding affinity from large libraries of ~106 variants, using HER2-binding antibodies as an example.
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Affiliation(s)
- Annalee W Nguyen
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA.
| | - Kevin Le
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Jennifer A Maynard
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
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Nguyen AW, Le KC, Maynard JA. Identification of high affinity HER2 binding antibodies using CHO Fab surface display. Protein Eng Des Sel 2019; 31:91-101. [PMID: 29566240 DOI: 10.1093/protein/gzy004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 02/02/2018] [Indexed: 12/27/2022] Open
Abstract
Discovery of monoclonal antibodies is most commonly performed using phage or yeast display but mammalian cells are used for production because of the complex antibody structure, including the multiple disulfide bonds and glycosylation, required for function. As this transition between host organisms is often accompanied by impaired binding, folding or expression, development pipelines include laborious plate-based screening or engineering strategies to adapt an antibody to mammalian expression. To circumvent these problems, we developed a plasmid-based Fab screening platform on Chinese hamster ovary (CHO) cells which allows for antibody selection in the production host and in the presence of the same post-translational modifications as the manufactured product. A hu4D5 variant with low affinity for the human epidermal growth factor receptor (HER2) growth factor receptor was mutagenized and this library of ~10(6) unique clones was screened to identify variants with up to 400-fold enhanced HER2 binding. After two rounds of fluorescence activated cell sorting (FACS), four unique clones exhibited improved antigen binding when expressed on the CHO surface or as purified human IgG. Three of the four clones contained free cysteines in third complementarity determining region of the antibody heavy chain, which did not impair expression or cause aggregation. The improved clones had similar yields and stabilities as hu4D5 and similar sub-nanomolar affinities as measured by equilibrium binding to target cells. The limited size of mammalian libraries restricts the utility of this approach for naïve antibody library screening, but it is a powerful approach for antibody affinity maturation or specificity enhancement and is readily generalizable to engineering other surface receptors, including T-cell receptors and chimeric antigen receptors.
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Affiliation(s)
- Annalee W Nguyen
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
| | - Kevin C Le
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
| | - Jennifer A Maynard
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
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Véliz Montes C, Memczak H, Gyssels E, Torres T, Madder A, Schneider RJ. Photoinduced Cross-Linking of Short Furan-Modified DNA on Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:1197-1201. [PMID: 28094979 DOI: 10.1021/acs.langmuir.6b03855] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report for the first time the formation of site-specific interstrand cross-linked (ICL) surface-immobilized furan-modified DNA duplexes via singlet oxygen. 1O2, necessary for effecting furan-mediated ICL formation, was produced in situ using methylene blue or a zinc phthalocyanine derivative (TT1) as a photosensitizer. Via surface plasmon resonance spectroscopy, we show that surface ICL was achieved, and a robust link formed that enhances the stability of the 12-mer duplex even after surface regeneration. The described method represents a novel platform technology based on surfaces with addressable and stable DNA duplexes requiring only short oligonucleotides.
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Affiliation(s)
- Cinthya Véliz Montes
- Department of Analytical Chemistry; Reference Materials, BAM Federal Institute for Materials Research and Testing , Richard-Willstätter-Str. 11, D-12489 Berlin, Germany
- Department of Organic Chemistry, University Autónoma of Madrid , Cantoblanco, 28049 Madrid, Spain
| | - Henry Memczak
- Branch Bioanalytics and Bioprocesses, IZI-BB Fraunhofer Institute for Cell Therapy and Immunology , Am Mühlenberg 11, D-14476 Potsdam, Germany
| | - Ellen Gyssels
- Faculty of Sciences, Department of Organic and Macromolecular Chemistry, Organic and Biomimetic Chemistry Research Group, Ghent University , Krijgslaan 281 (S4), 9000 Ghent, Belgium
| | - Tomás Torres
- Department of Organic Chemistry, University Autónoma of Madrid , Cantoblanco, 28049 Madrid, Spain
- IMDEA Nanoscience , c/Faraday, 9, Cantoblanco, 28049 Madrid, Spain
| | - Annemieke Madder
- Faculty of Sciences, Department of Organic and Macromolecular Chemistry, Organic and Biomimetic Chemistry Research Group, Ghent University , Krijgslaan 281 (S4), 9000 Ghent, Belgium
| | - Rudolf J Schneider
- Department of Analytical Chemistry; Reference Materials, BAM Federal Institute for Materials Research and Testing , Richard-Willstätter-Str. 11, D-12489 Berlin, Germany
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Eisold U, Sellrie F, Schenk JA, Lenz C, Stöcklein WFM, Kumke MU. Bright or dark immune complexes of anti-TAMRA antibodies for adapted fluorescence-based bioanalysis. Anal Bioanal Chem 2015; 407:3313-23. [PMID: 25711988 DOI: 10.1007/s00216-015-8538-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 01/14/2015] [Accepted: 02/06/2015] [Indexed: 11/26/2022]
Abstract
Fluorescence labels, for example fluorescein or rhodamin derivatives, are widely used in bioanalysis applications including lateral-flow assays, PCR, and fluorescence microscopy. Depending on the layout of the particular application, fluorescence quenching or enhancement may be desired as the detection principle. Especially for multiplexed applications or high-brightness requirements, a tunable fluorescence probe can be beneficial. The alterations in the photophysics of rhodamine derivatives upon binding to two different anti-TAMRA antibodies were investigated by absorption and fluorescence-spectroscopy techniques, especially determining the fluorescence decay time and steady-state and time-resolved fluorescence anisotropy. Two monoclonal anti-TAMRA antibodies were generated by the hybridoma technique. Although surface-plasmon-resonance measurements clearly proved the high affinity of both antibodies towards 5-TAMRA, the observed effects on the fluorescence of rhodamine derivatives were very different. Depending on the anti-TAMRA antibody either a strong fluorescence quenching (G71-DC7) or a distinct fluorescence enhancement (G71-BE11) upon formation of the immune complex was observed. Additional rhodamine derivatives were used to gain further information on the binding interaction. The data reveal that such haptens as 5-TAMRA could generate different paratopes with equal binding affinities but different binding interactions, which provide the opportunity to adapt bioanalysis methods including immunoassays for optimized detection principles for the same hapten depending on the specific requirements.
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Affiliation(s)
- Ursula Eisold
- Department of Chemistry, Physical Chemistry, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
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Hovestädt M, Memczak H, Pleiner D, Zhang X, Rappich J, Bier FF, Stöcklein WFM. Characterization of a new maleimido functionalization of gold for surface plasmon resonance spectroscopy. J Mol Recognit 2014; 27:707-13. [PMID: 25319618 DOI: 10.1002/jmr.2396] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 05/16/2014] [Accepted: 05/16/2014] [Indexed: 11/06/2022]
Abstract
Para-maleimidophenyl (p-MP) modified gold surfaces have been prepared by one-step electrochemical deposition and used in surface plasmon resonance (SPR) studies. Therefore, a FITC mimotope peptide (MP1, 12 aa), a human mucin 1 epitope peptide (MUC, 9 aa) and a protein with their specific antibodies were used as model systems. The peptides were modified with an N-terminal cysteine for covalent and directed coupling to the maleimido functionalized surface by means of Michael addition. The coupling yield of the peptide, the binding characteristics of antibody and the unspecific adsorption of the analytes were investigated. The results expand the spectrum of biosensors usable with p-MP by widely used SPR and support its potential to be versatile for several electrochemical and optical biosensors. This allows the combination of an electrochemical and optical read-out for a broad variety of biomolecular interactions on the same chip.
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Affiliation(s)
- Marc Hovestädt
- Fraunhofer Institute for Biomedical Engineering IBMT, Branch Potsdam, Department of Molecular Bioanalytics and Bioelectronics, Am Mühlenberg 13, 14476, Potsdam, Germany; University of Potsdam, Institute of Biochemistry and Biology, Karl-Liebknecht-Straße 24/25, 14476, Potsdam, Germany
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Stech M, Hust M, Schulze C, Dübel S, Kubick S. Cell-free eukaryotic systems for the production, engineering, and modification of scFv antibody fragments. Eng Life Sci 2014; 14:387-398. [PMID: 25821419 PMCID: PMC4374706 DOI: 10.1002/elsc.201400036] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/06/2014] [Accepted: 05/08/2014] [Indexed: 01/27/2023] Open
Abstract
Open cell-free translation systems based on Escherichia coli cell lysates have successfully been used to produce antibodies and antibody fragments. In this study, we demonstrate the cell-free expression of functional single-chain antibody variable fragments (scFvs) in a eukaryotic and endotoxin-free in vitro translation system based on Spodoptera frugiperda (Sf21) insect cell extracts. Three scFv candidates with different specificities were chosen as models. The first scFv candidate SH527-IIA4 specifically discriminates between its phosphorylated (SMAD2-P) and nonphosphorylated antigens (SMAD2) (where SMAD is mothers against decapentaplegic homolog 2), whereas the second scFv candidate SH527-IIC10 recognizes both, SMAD2-P and SMAD2. The third scFv candidate SH855-C11 binds specifically to a linear epitope of the CXC chemokine receptor type 5. The translocation of antibody fragments into the lumen of endogenous microsomal vesicles, which are contained in the lysate, was facilitated by fusion of scFv genes to the insect cell specific signal sequence of honeybee melittin. We compared the binding capabilities of scFv fragments with and without melittin signal peptide and detected that translocated scFv fragments were highly functional, whereas scFvs synthesized in the cytosol of the cell extract showed strongly decreased binding capabilities. Additionally, we describe a cell-free protein synthesis method for the incorporation of noncanonical amino acids into scFv molecules in eukaryotic cell lysates. We demonstrate the successful cotranslational labeling of de novo synthesized scFv molecules with fluorescent amino acids, using residue-specific as well as site-specific labeling.
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Affiliation(s)
- Marlitt Stech
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses Potsdam-Golm Potsdam, Germany
| | - Michael Hust
- Department of Biotechnology, Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig Braunschweig, Germany
| | - Corina Schulze
- Department of Life Sciences and Technology, Beuth Hochschule für Technik Berlin, University of Applied Sciences Berlin, Germany
| | - Stefan Dübel
- Department of Biotechnology, Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig Braunschweig, Germany
| | - Stefan Kubick
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses Potsdam-Golm Potsdam, Germany
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Antibody mediated fluorescence enhancement of nucleoside analogue 1,3-diaza-2-oxophenoxazine (tC°). Talanta 2014; 124:67-70. [PMID: 24767447 DOI: 10.1016/j.talanta.2014.02.046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 02/14/2014] [Accepted: 02/20/2014] [Indexed: 11/20/2022]
Abstract
We report on the generation and analytical application of the monoclonal antibody G93-ED2 raised against the tricyclic fluorescent nucleoside analogue 1,3-diaza-2-oxophenoxazine (tC°). G93-ED2 is specifically binding this deoxycytidine analogue and was found to raise its fluorescence intensity by a factor of 5. This unique feature makes it a valuable tool in fluorescence dependent immunoassays. G93-ED2 was successfully applied in a homogeneous fluorescence quenching immunoassay (DNA-Q) for the sequence specific determination of DNA.
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Bowers PM, Horlick RA, Kehry MR, Neben TY, Tomlinson GL, Altobell L, Zhang X, Macomber JL, Krapf IP, Wu BF, McConnell AD, Chau B, Berkebile AD, Hare E, Verdino P, King DJ. Mammalian cell display for the discovery and optimization of antibody therapeutics. Methods 2013; 65:44-56. [PMID: 23792919 DOI: 10.1016/j.ymeth.2013.06.010] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 06/11/2013] [Accepted: 06/12/2013] [Indexed: 11/15/2022] Open
Abstract
Recent advances are described for the isolation and affinity maturation of antibodies that couple in vitro somatic hypermutation (SHM) with mammalian cell display, replicating key aspects of the adaptive immune system. SHM is dependent on the action of the B cell specific enzyme, activation-induced cytidine deaminase (AID). AID-directed SHM in vitro in non-B cells, combined with mammalian display of a library of human antibodies, initially naïve to SHM, can be used to isolate and affinity mature antibodies via iterative cycles of fluorescence-activated cell sorting (FACS) under increasingly stringent sort conditions. SHM observed in vitro closely resembles SHM observed in human antibodies in vivo in both mutation type and positioning in the antibody variable region. In addition, existing antibodies originating from mouse immunization, in vivo based libraries, or alternative display technologies such as phage can also be affinity matured in a similar manner. The display system has been developed to enable simultaneous high-level cell surface expression and secretion of the same protein through alternate splicing, where the displayed protein phenotype remains linked to genotype, allowing soluble secreted antibody to be simultaneously characterized in biophysical and cell-based functional assays. This approach overcomes many of the previous limitations of mammalian cell display, enabling direct selection and maturation of antibodies as full-length, glycosylated IgGs.
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Affiliation(s)
- Peter M Bowers
- AnaptysBio Inc., 10421 Pacific Center Court, San Diego, CA 92121, USA
| | - Robert A Horlick
- AnaptysBio Inc., 10421 Pacific Center Court, San Diego, CA 92121, USA
| | - Marilyn R Kehry
- AnaptysBio Inc., 10421 Pacific Center Court, San Diego, CA 92121, USA
| | - Tamlyn Y Neben
- AnaptysBio Inc., 10421 Pacific Center Court, San Diego, CA 92121, USA
| | | | - Larry Altobell
- AnaptysBio Inc., 10421 Pacific Center Court, San Diego, CA 92121, USA
| | - Xue Zhang
- AnaptysBio Inc., 10421 Pacific Center Court, San Diego, CA 92121, USA
| | - John L Macomber
- AnaptysBio Inc., 10421 Pacific Center Court, San Diego, CA 92121, USA
| | - Irina P Krapf
- AnaptysBio Inc., 10421 Pacific Center Court, San Diego, CA 92121, USA
| | - Betty F Wu
- AnaptysBio Inc., 10421 Pacific Center Court, San Diego, CA 92121, USA
| | | | - Betty Chau
- AnaptysBio Inc., 10421 Pacific Center Court, San Diego, CA 92121, USA
| | | | - Eric Hare
- AnaptysBio Inc., 10421 Pacific Center Court, San Diego, CA 92121, USA
| | - Petra Verdino
- AnaptysBio Inc., 10421 Pacific Center Court, San Diego, CA 92121, USA
| | - David J King
- AnaptysBio Inc., 10421 Pacific Center Court, San Diego, CA 92121, USA.
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Neumann-Schaal M, Messerschmidt K, Grenz N, Heilmann K. Use of antibody gene library for the isolation of specific single chain antibodies by ampicillin-antigen conjugates. Immunol Lett 2013; 151:39-43. [PMID: 23453960 DOI: 10.1016/j.imlet.2013.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 02/12/2013] [Indexed: 11/26/2022]
Abstract
Isolation of recombinant antibodies from antibody libraries is commonly performed by different molecular display formats including phage display and ribosome display or different cell-surface display formats. We describe a new method which allows the selection of Escherichia coli cells producing the required single chain antibody by cultivation in presence of ampicillin conjugated to the antigen of interest. The method utilizes the neutralization of the conjugate by the produced single chain antibody which is secreted to the periplasm. Therefore, a new expression system based on the pET26b vector was designed and a library was constructed. The method was successfully established first for the selection of E. coli BL21 Star (DE3) cells expressing a model single chain antibody (anti-fluorescein) by a simple selection assay on LB-agar plates. Using this selection assay, we could identify a new single chain antibody binding biotin by growing E. coli BL21 Star (DE3) containing the library in presence of a biotin-ampicillin conjugate. In contrast to methods as molecular or cell surface display our selection system applies the soluble single chain antibody molecule and thereby avoids undesired effects, e.g. by the phage particle or the yeast fusion protein. By selecting directly in an expression strain, production and characterization of the selected single chain antibody is possible without any further cloning or transformation steps.
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Affiliation(s)
- Meina Neumann-Schaal
- University of Potsdam, Institute of Biochemistry and Biology, Junior Research Group Antibody Technologies, Karl-Liebknecht-Straße 24-25, 14476 Golm, Germany.
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Production of functional antibody fragments in a vesicle-based eukaryotic cell-free translation system. J Biotechnol 2012; 164:220-31. [PMID: 22982167 DOI: 10.1016/j.jbiotec.2012.08.020] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 08/15/2012] [Accepted: 08/30/2012] [Indexed: 12/17/2022]
Abstract
Cell-free protein synthesis is of increasing interest for the rapid and high-throughput synthesis of many proteins, in particular also antibody fragments. In this study, we present a novel strategy for the production of single chain antibody fragments (scFv) in a eukaryotic in vitro translation system. This strategy comprises the cell-free expression, isolation and label-free interaction analysis of a model antibody fragment synthesized in two differently prepared insect cell lysates. These lysates contain translocationally active microsomal structures derived from the endoplasmic reticulum (ER), allowing for posttranslational modifications of cell-free synthesized proteins. Both types of these insect cell lysates enable the synthesis and translocation of scFv into ER-derived vesicles. However, only the one that has a specifically adapted redox potential yields functional active antibody fragments. We have developed a new methodology for the isolation of functional target proteins based on the translocation of cell-free produced scFv into microsomal structures and subsequent collection of protein-enriched vesicles. Antibody fragments that have been released from these vesicles are shown to be well suited for label-free binding studies. Altogether, these results show the potential of insect cell lysates for the production, purification and selection of antibody fragments in an easy-to-handle and time-saving manner.
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Abstract
Antibody engineering has generally been carried out by displaying mouse or human antibodies or antibody fragments on the surface of microorganisms (phage, bacteria, and yeast). We have shown that mammalian cells can be used to display single-chain antibody fragments (scFvs) for affinity maturation. Using mammalian cell display one can isolate and engineer scFvs, Fabs, or whole IgGs for increased affinity and other specific biological functions. Here, we describe a mammalian cell display strategy to isolate high-affinity scFvs specific for CD22. Our strategy uses flow cytometry and human embryonic kidney 293T (HEK-293T) cells that are widely used for transient protein expression. Flow cytometry enhances the screen's sensitivity thereby allowing us to isolate high-affinity antibodies.
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Affiliation(s)
- Mitchell Ho
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Ira Pastan
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
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Abstract
We describe a human cell display strategy to isolate high-affinity single-chain antibody fragments (scFvs) specific for CD22 for the treatment of B-cell malignancies. Our strategy uses flow cytometry and human embryonic kidney 293T (HEK-293T) cells that are widely used for transient protein expression. Flow cytometry enhances the screen's sensitivity thereby allowing us to isolate high-affinity scFvs. Using human cell display, one could isolate and engineer scFvs, single domains, Fabs, or whole IgGs for increased affinity and other biological functions.
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Affiliation(s)
- Mitchell Ho
- Laboratory of Molecular Biology, National Cancer Institute, Bethesda, MD 20892-4264, USA
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Rich RL, Myszka DG. Survey of the year 2007 commercial optical biosensor literature. J Mol Recognit 2008; 21:355-400. [DOI: 10.1002/jmr.928] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Sellrie F, Micheel B. Selection of recombinant antibody-producing E. coli cells by means of toxin conjugates. Biochem Eng J 2008. [DOI: 10.1016/j.bej.2007.07.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Jordan E, Al-Halabi L, Schirrmann T, Hust M, Dübel S. Production of single chain Fab (scFab) fragments in Bacillus megaterium. Microb Cell Fact 2007; 6:38. [PMID: 18042285 PMCID: PMC2212634 DOI: 10.1186/1475-2859-6-38] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Accepted: 11/27/2007] [Indexed: 11/10/2022] Open
Abstract
Background The demand on antigen binding reagents in research, diagnostics and therapy raises questions for novel antibody formats as well as appropriate production systems. Recently, the novel single chain Fab (scFab) antibody format combining properties of single chain Fv (scFv) and Fab fragments was produced in the Gram-negative bacterium Escherichia coli. In this study we evaluated the Gram-positive bacterium Bacillus megaterium for the recombinant production of scFab and scFvs in comparison to E. coli. Results The lysozyme specific D1.3 scFab was produced in B. megaterium and E. coli. The total yield of the scFab after purification obtained from the periplasmic fraction and culture supernatant of E. coli was slightly higher than that obtained from culture supernatant of B. megaterium. However, the yield of functional scFab determined by analyzing the antigen binding activity was equally in both production systems. Furthermore, a scFv fragment with specificity for the human C reactive protein was produced in B. megaterium. The total yield of the anti-CRP scFv produced in B. megaterium was slightly lower compared to E. coli, whereas the specific activity of the purified scFvs produced in B. megaterium was higher compared to E. coli. Conclusion B. megaterium allows the secretory production of antibody fragments including the novel scFab antibody format. The yield and quality of functional antibody fragment is comparable to the periplasmic production in E. coli.
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Affiliation(s)
- Eva Jordan
- Technische Universität Braunschweig, Institut für Biochemie und Biotechnologie, Abteilung Biotechnologie, Spielmannstr, 7, 38106 Braunschweig, Germany.
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