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Zhang Z, Zhan F. Type 2 Cystatins and Their Roles in the Regulation of Human Immune Response and Cancer Progression. Cancers (Basel) 2023; 15:5363. [PMID: 38001623 PMCID: PMC10670837 DOI: 10.3390/cancers15225363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 11/08/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
Cystatins are a family of intracellular and extracellular protease inhibitors that inhibit cysteine cathepsins-a group of lysosomal cysteine proteases that participate in multiple biological processes, including protein degradation and post-translational cleavage. Cysteine cathepsins are associated with the development of autoimmune diseases, tumor progression, and metastasis. Cystatins are categorized into three subfamilies: type 1, type 2, and type 3. The type 2 cystatin subfamily is the largest, containing 10 members, and consists entirely of small secreted proteins. Although type 2 cystatins have many shared biological roles, each member differs in structure, post-translational modifications (e.g., glycosylation), and expression in different cell types. These distinctions allow the type 2 cystatins to have unique biological functions and properties. This review provides an overview of type 2 cystatins, including their biological similarities and differences, their regulatory effect on human immune responses, and their roles in tumor progression, immune evasion, and metastasis.
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Affiliation(s)
| | - Fenghuang Zhan
- Myeloma Center, Winthrop P. Rockefeller Cancer Institute, Department of Internal Medicine, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA;
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2
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Murillo AMM, Tomé-Amat J, Ramírez Y, Garrido-Arandia M, Valle LG, Hernández-Ramírez G, Tramarin L, Herreros P, Santamaría B, Díaz-Perales A, Holgado M. Developing an Optical Interferometric Detection Method based biosensor for detecting specific SARS-CoV-2 immunoglobulins in Serum and Saliva, and their corresponding ELISA correlation. SENSORS AND ACTUATORS. B, CHEMICAL 2021; 345:130394. [PMID: 34248283 PMCID: PMC8253720 DOI: 10.1016/j.snb.2021.130394] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 06/10/2021] [Accepted: 06/30/2021] [Indexed: 05/31/2023]
Abstract
The standard rapid approach for the diagnosis of coronavirus disease 2019 (COVID-19) is the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA. The detection of specific anti-SARS-CoV-2 immunoglobulins is crucial for screening people who have been exposed to the virus, whether or not they presented symptoms. Recent publications report different methods for the detection of specific IgGs, IgMs, and IgAs against SARS-CoV-2; these methods mainly detect immunoglobulins in the serum using conventional techniques such as rapid lateral flow tests or enzyme-linked immunosorbent assay (ELISA). In this article, we report the production of recombinant SARS-CoV-2 spike protein and the development of a rapid, reliable, cost-effective test, capable of detecting immunoglobulins in serum and saliva samples. This method is based on interferometric optical detection. The results obtained using this method and those obtained using ELISA were compared. Owing to its low cost and simplicity, this test can be used periodically for the early detection, surveillance, detection of immunity, and control of the spread of COVID-19.
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Affiliation(s)
- A M M Murillo
- Center for Biomedical Technology (CTB), Universidad Politécnica de Madrid, Parque Científico y Tecnológico de la UPM, Campus de Montegancedo, 28223, Pozuelo de Alarcón, Madrid, Spain
- BioOptical Detection SL, Centro de Empresas, Campus Montegancedo, 28223, Madrid, Spain
| | - J Tomé-Amat
- Center for Plant Biotechnology and Genomics (CBGP), Universidad Politécnica de Madrid, Parque Científico y Tecnológico de la UPM. Campus de Montegancedo. 28223, Pozuelo de Alarcón, Madrid, Spain
| | - Y Ramírez
- Center for Biomedical Technology (CTB), Universidad Politécnica de Madrid, Parque Científico y Tecnológico de la UPM, Campus de Montegancedo, 28223, Pozuelo de Alarcón, Madrid, Spain
- BioOptical Detection SL, Centro de Empresas, Campus Montegancedo, 28223, Madrid, Spain
| | - M Garrido-Arandia
- Center for Plant Biotechnology and Genomics (CBGP), Universidad Politécnica de Madrid, Parque Científico y Tecnológico de la UPM. Campus de Montegancedo. 28223, Pozuelo de Alarcón, Madrid, Spain
| | - L G Valle
- Center for Biomedical Technology (CTB), Universidad Politécnica de Madrid, Parque Científico y Tecnológico de la UPM, Campus de Montegancedo, 28223, Pozuelo de Alarcón, Madrid, Spain
- Group of Organ and Tissue on-a-chip and In-Vitro Detection, Health Research Institute of the Hospital Clínico San Carlos, IdISSC. C/ Profesor Martín Lagos s/n, 4ª Planta Sur 28040, Madrid, Spain
| | - G Hernández-Ramírez
- Center for Plant Biotechnology and Genomics (CBGP), Universidad Politécnica de Madrid, Parque Científico y Tecnológico de la UPM. Campus de Montegancedo. 28223, Pozuelo de Alarcón, Madrid, Spain
| | - L Tramarin
- Center for Biomedical Technology (CTB), Universidad Politécnica de Madrid, Parque Científico y Tecnológico de la UPM, Campus de Montegancedo, 28223, Pozuelo de Alarcón, Madrid, Spain
- Group of Organ and Tissue on-a-chip and In-Vitro Detection, Health Research Institute of the Hospital Clínico San Carlos, IdISSC. C/ Profesor Martín Lagos s/n, 4ª Planta Sur 28040, Madrid, Spain
- Department of Applied Physics and Materials Engineering, Escuela Técnica Superior de Ingenieros Industriales, Universidad Politécnica de Madrid, C/José Gutiérrez Abascal, 2, 28006, Madrid, Spain
| | - P Herreros
- Center for Biomedical Technology (CTB), Universidad Politécnica de Madrid, Parque Científico y Tecnológico de la UPM, Campus de Montegancedo, 28223, Pozuelo de Alarcón, Madrid, Spain
- Group of Organ and Tissue on-a-chip and In-Vitro Detection, Health Research Institute of the Hospital Clínico San Carlos, IdISSC. C/ Profesor Martín Lagos s/n, 4ª Planta Sur 28040, Madrid, Spain
- Department of Applied Physics and Materials Engineering, Escuela Técnica Superior de Ingenieros Industriales, Universidad Politécnica de Madrid, C/José Gutiérrez Abascal, 2, 28006, Madrid, Spain
| | - B Santamaría
- Center for Biomedical Technology (CTB), Universidad Politécnica de Madrid, Parque Científico y Tecnológico de la UPM, Campus de Montegancedo, 28223, Pozuelo de Alarcón, Madrid, Spain
- Group of Organ and Tissue on-a-chip and In-Vitro Detection, Health Research Institute of the Hospital Clínico San Carlos, IdISSC. C/ Profesor Martín Lagos s/n, 4ª Planta Sur 28040, Madrid, Spain
| | - A Díaz-Perales
- Center for Plant Biotechnology and Genomics (CBGP), Universidad Politécnica de Madrid, Parque Científico y Tecnológico de la UPM. Campus de Montegancedo. 28223, Pozuelo de Alarcón, Madrid, Spain
- Group of Organ and Tissue on-a-chip and In-Vitro Detection, Health Research Institute of the Hospital Clínico San Carlos, IdISSC. C/ Profesor Martín Lagos s/n, 4ª Planta Sur 28040, Madrid, Spain
| | - M Holgado
- Center for Biomedical Technology (CTB), Universidad Politécnica de Madrid, Parque Científico y Tecnológico de la UPM, Campus de Montegancedo, 28223, Pozuelo de Alarcón, Madrid, Spain
- Group of Organ and Tissue on-a-chip and In-Vitro Detection, Health Research Institute of the Hospital Clínico San Carlos, IdISSC. C/ Profesor Martín Lagos s/n, 4ª Planta Sur 28040, Madrid, Spain
- Department of Applied Physics and Materials Engineering, Escuela Técnica Superior de Ingenieros Industriales, Universidad Politécnica de Madrid, C/José Gutiérrez Abascal, 2, 28006, Madrid, Spain
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Benitez-del-Castillo JM, Soria J, Acera A, Muñoz AM, Rodríguez S, Suárez T. Quantification of a panel for dry-eye protein biomarkers in tears: A comparative pilot study using standard ELISA and customized microarrays. Mol Vis 2021; 27:243-261. [PMID: 34012227 PMCID: PMC8116255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 05/06/2021] [Indexed: 11/01/2022] Open
Abstract
Purpose This paper examines the tear concentration of cystatin S (CST4), calcyclin (S100A6), calgranulin A (S100A8), and matrix metalloproteinase 9 (MMP9), and the correlation between biomarker expression, clinical parameters, and disease severity in patients suffering from dry eye (DE). A comparison of the results is obtained via ELISA tests and customized antibody microarrays for protein quantification. Methods This single-center, observational study recruited 59 participants (45 DE and 14 controls). Clinical evaluation included an Ocular Surface Disease Index (OSDI) questionnaire, a tear osmolarity (OSM) test, the Schirmer test (SCH), tear breakup time (TBUT), fluorescein (FLUO) and lissamine green (LG) corneal staining, and meibomian gland evaluation (MGE). Tear concentrations of CST4, S100A6, S100A8, and MMP9 were measured using standard individual ELISA assays. The levels of CST4, S100A6, and MMP9 were also measured using customized multiplexed antibody microarrays. Correlations between variables were evaluated, and a significance level was p value <0.05. Results The quantification of tear protein biomarkers with ELISA showed that the concentration of CST4 was significantly (2.14-fold) reduced in tears of DE patients in comparison with control (CT) subjects (p < 0.001). S100A6 and S100A8 concentrations were significantly higher in the tears of DE patients (1.36- and 2.29-fold; p < 0.001 and 0.025, respectively) in comparison with CT. The MMP9 level was also higher in DE patients (5.83-fold), but not significantly (p = 0.22). The changes in CST4 and S100A6 concentrations were significantly correlated with dry eye disease (DED) severity. Quantification of CST4, S100A6, and MMP9, using antibody microarrays, confirmed the ELISA results. Similar trends were observed: 1.83-fold reduction for CST4 (p value 0.01), 8.63-fold increase for S100A6 (p value <0.001) and 9.67-fold increase for MMP9 (p value 0.94), but with higher sensitivity. The biomarker concentrations were significantly associated with the signs and symptoms related with DED. Conclusions S100A6, S100A8, and CST4 diagnostic biomarkers strongly correlate with DED clinical parameters. S100A6 and CST4 are also useful for grading DE severity. The multiplexed antibody microarray technique, used here for tear multi-marker quantification, appears more sensitive than standard ELISA tests.
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Affiliation(s)
- José Manuel Benitez-del-Castillo
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Facultad de Medicina. Universidad Complutense de Madrid, Madrid, Spain,Ophthalmology Department, Hospital Clínico San Carlos, Madrid, Spain
| | - Javier Soria
- Bioftalmik Applied Research. Bizkaia Science and Technology Park, Bizkaia, Spain
| | - Arantxa Acera
- Bioftalmik Applied Research. Bizkaia Science and Technology Park, Bizkaia, Spain
| | - Ana María Muñoz
- Ophthalmology Department, Hospital Clínico San Carlos, Madrid, Spain
| | - Sandra Rodríguez
- Bioftalmik Applied Research. Bizkaia Science and Technology Park, Bizkaia, Spain
| | - Tatiana Suárez
- Bioftalmik Applied Research. Bizkaia Science and Technology Park, Bizkaia, Spain
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Espinosa R, Garrido-Arandia M, Romero-Sahagun A, Herreros P, Tramarin L, Laguna M, Díaz-Perales A, Holgado M. A new optical interferometric-based in vitro detection system for the specific IgE detection in serum of the main peach allergen. Biosens Bioelectron 2020; 169:112641. [DOI: 10.1016/j.bios.2020.112641] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/19/2020] [Accepted: 09/17/2020] [Indexed: 12/31/2022]
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Schechinger M, Marks H, Mabbott S, Choudhury M, Cote' G. A SERS approach for rapid detection of microRNA-17 in the picomolar range. Analyst 2019; 144:4033-4044. [PMID: 31143920 DOI: 10.1039/c9an00653b] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Epigenetic biomarkers are powerful tools for early disease detection and are particularly useful for elusive conditions like preeclampsia. Predicting preeclampsia at an early stage is one of the most important goals of maternal-fetal medicine. To this end, recent studies have identified microRNAs-such as microRNA-17-as early biomarkers for preeclampsia. Yet clinical applications are lagging, owing in part to the sensing challenges presented by the biomarkers' small size and complex environment. Surface enhanced Raman spectroscopy (SERS) is an emergent optical technique that is recognized for its potential to overcome these challenges. In this study, DNA functionalized nanoparticles were designed as probes to capture and quantify miRNA-17 in solution. SERS was used to determine the presence and concentration of miRNA-17 based on the formation of plasmonic nanoparticle aggregates. The miRNA-17 assay was tested at concentrations of 1 pM to 1 nM in both PBS and a representative complex biological sample. In both situations the assay was unaffected by non-complementary microRNA samples. These results demonstrate SERS's specificity and sensitivity for a new biomarker (miRNA-17) that may ultimately be used in a detection platform for early diagnosis of preeclampsia.
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Affiliation(s)
- Monika Schechinger
- Texas A&M University, Department of Biomedical Engineering, 5045 Emerging Technologies Building, College Station, Texas 77843, USA.
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Espinosa RL, Laguna MF, Fernández F, Santamaria B, Sanza FJ, Maigler MV, Álvarez-Millán JJ, Canalejas-Tejero V, Holgado M. A Proof-of-Concept of Label-Free Biosensing System for Food Allergy Diagnostics in Biophotonic Sensing Cells: Performance Comparison with ImmunoCAP. SENSORS 2018; 18:s18082686. [PMID: 30111765 PMCID: PMC6111936 DOI: 10.3390/s18082686] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 08/03/2018] [Accepted: 08/13/2018] [Indexed: 01/11/2023]
Abstract
Food allergy is a common disease worldwide with over 6% of the population (200⁻250 million people) suffering from any food allergy nowadays. The most dramatic increase seems to be happening in children and young people. Therefore, improvements in the diagnosis efficiency of these diseases are needed. Immunoglobulin type E (IgE) biomarker determination in human serum is a typical in vitro test for allergy identification. In this work, we used a novel biosensor based on label-free photonic transducers called BICELLs (Biophotonic Sensing Cells) for IgE detection. These BICELLs have a thin film of nitrocellulose over the sensing surface, they can be vertical optically interrogated, and are suitable for being integrated on a chip. The BICELLs sensing surface sizes used were 100 and 800 µm in diameter. We obtained calibration curves with IgE standards by immobilizating anti-IgE antibodies and identified with standard IgE calibrators in minute sample amounts (3 µL). The results, in similar assay format, were compared with commercially available ImmunoCAP®. The versatility of the interferometric nitrocellulose-based sensing surface was demonstrated since the limit of detections for BICELLs and ImmunoCAP® were 0.7 and 0.35 kU/L, respectively.
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Affiliation(s)
- Rocio L Espinosa
- Center for Biomedical Technology, Optics, Photonics and Biophotonics Lab., Universidad Politécnica de Madrid, Campus Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain.
| | - María Fe Laguna
- Center for Biomedical Technology, Optics, Photonics and Biophotonics Lab., Universidad Politécnica de Madrid, Campus Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain.
- Department of Applied Physics and Materials Engineering, Escuela Técnica Superior de Ingenieros Industriales, Universidad Politécnica de Madrid, C/José Gutierrez Abascal 2, 28006 Madrid, Spain.
| | - Fátima Fernández
- CQS Laboratory, Calle Marie Curie, 5, Rivas-Vaciamadrid, 28521 Madrid, Spain.
| | - Beatriz Santamaria
- Center for Biomedical Technology, Optics, Photonics and Biophotonics Lab., Universidad Politécnica de Madrid, Campus Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain.
- Department of Applied Physics and Materials Engineering, Escuela Técnica Superior de Ingenieros Industriales, Universidad Politécnica de Madrid, C/José Gutierrez Abascal 2, 28006 Madrid, Spain.
| | | | - Maria Victoria Maigler
- Center for Biomedical Technology, Optics, Photonics and Biophotonics Lab., Universidad Politécnica de Madrid, Campus Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain.
- BioOptical Detection SL, Centro de Empresas, Campus Montegancedo, 28223 Madrid, Spain.
| | | | - Víctor Canalejas-Tejero
- Center for Biomedical Technology, Optics, Photonics and Biophotonics Lab., Universidad Politécnica de Madrid, Campus Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain.
| | - Miguel Holgado
- Center for Biomedical Technology, Optics, Photonics and Biophotonics Lab., Universidad Politécnica de Madrid, Campus Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain.
- Department of Applied Physics and Materials Engineering, Escuela Técnica Superior de Ingenieros Industriales, Universidad Politécnica de Madrid, C/José Gutierrez Abascal 2, 28006 Madrid, Spain.
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Abstract
The members of the Tear Film Subcommittee reviewed the role of the tear film in dry eye disease (DED). The Subcommittee reviewed biophysical and biochemical aspects of tears and how these change in DED. Clinically, DED is characterized by loss of tear volume, more rapid breakup of the tear film and increased evaporation of tears from the ocular surface. The tear film is composed of many substances including lipids, proteins, mucins and electrolytes. All of these contribute to the integrity of the tear film but exactly how they interact is still an area of active research. Tear film osmolarity increases in DED. Changes to other components such as proteins and mucins can be used as biomarkers for DED. The Subcommittee recommended areas for future research to advance our understanding of the tear film and how this changes with DED. The final report was written after review by all Subcommittee members and the entire TFOS DEWS II membership.
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TFOS DEWS II Diagnostic Methodology report. Ocul Surf 2017; 15:539-574. [DOI: 10.1016/j.jtos.2017.05.001] [Citation(s) in RCA: 836] [Impact Index Per Article: 119.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 05/01/2017] [Indexed: 01/09/2023]
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Santamaría B, Laguna MF, López-Romero D, Hernandez AL, Sanza FJ, Lavín Á, Casquel R, Maigler MV, Espinosa RL, Holgado M. Development towards Compact Nitrocellulose-Based Interferometric Biochips for Dry Eye MMP9 Label-Free In-Situ Diagnosis. SENSORS 2017; 17:s17051158. [PMID: 28534808 PMCID: PMC5470904 DOI: 10.3390/s17051158] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 05/13/2017] [Accepted: 05/16/2017] [Indexed: 11/16/2022]
Abstract
A novel compact optical biochip based on a thin layer-sensing surface of nitrocellulose is used for in-situ label-free detection of metalloproteinase (MMP9) related to dry eye disease. In this article, a new integrated chip with different interferometric transducers layout with an optimal sensing surface is reported for the first time. We demonstrate that specific antibodies can be immobilized onto these transducers with a very low volume of sample and with good orientation. Many sensing transducers constitute the presented biochip in order to yield statistical data and stability in the acquired measurements. As a result, we report the recognition curve for pure recombinant MMP9, tests of model tears with MMP9, and real tear performance from patients, with a promising limit of detection.
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Affiliation(s)
- Beatriz Santamaría
- Centre for Biomedical Technology, Optics, Photonics and Biophotinics Laboratory, Campus Montegancedo, Universidad Politécnica de Madrid, 28223 Madrid, Spain.
| | - María F Laguna
- Centre for Biomedical Technology, Optics, Photonics and Biophotinics Laboratory, Campus Montegancedo, Universidad Politécnica de Madrid, 28223 Madrid, Spain.
| | - David López-Romero
- BioOptical Detection, Centro de Empresas, Campus Montegancedo, 28223 Madrid, Spain.
| | - Ana L Hernandez
- Centre for Biomedical Technology, Optics, Photonics and Biophotinics Laboratory, Campus Montegancedo, Universidad Politécnica de Madrid, 28223 Madrid, Spain.
| | - Francisco J Sanza
- BioOptical Detection, Centro de Empresas, Campus Montegancedo, 28223 Madrid, Spain.
| | - Álvaro Lavín
- Centre for Biomedical Technology, Optics, Photonics and Biophotinics Laboratory, Campus Montegancedo, Universidad Politécnica de Madrid, 28223 Madrid, Spain.
| | - Rafael Casquel
- Centre for Biomedical Technology, Optics, Photonics and Biophotinics Laboratory, Campus Montegancedo, Universidad Politécnica de Madrid, 28223 Madrid, Spain.
| | - María V Maigler
- BioOptical Detection, Centro de Empresas, Campus Montegancedo, 28223 Madrid, Spain.
| | - Rocío L Espinosa
- Centre for Biomedical Technology, Optics, Photonics and Biophotinics Laboratory, Campus Montegancedo, Universidad Politécnica de Madrid, 28223 Madrid, Spain.
| | - Miguel Holgado
- Centre for Biomedical Technology, Optics, Photonics and Biophotinics Laboratory, Campus Montegancedo, Universidad Politécnica de Madrid, 28223 Madrid, Spain.
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Niesen J, Sack M, Seidel M, Fendel R, Barth S, Fischer R, Stein C. SNAP-Tag Technology: A Useful Tool To Determine Affinity Constants and Other Functional Parameters of Novel Antibody Fragments. Bioconjug Chem 2016; 27:1931-41. [PMID: 27391930 DOI: 10.1021/acs.bioconjchem.6b00315] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Antibody derivatives, such as the single chain fragment variable (scFv), can be developed as diagnostic and therapeutic tools in cancer research, especially in the form of fusion proteins. Such derivatives are easier to produce and modify than monoclonal antibodies (mAbs) and achieve better tissue/tumor penetration. The genetic modification of scFvs is also much more straightforward than the challenging chemical modification of mAbs. Therefore, we constructed two scFvs derived from the approved monoclonal antibodies cetuximab (scFv2112) and panitumumab (scFv1711), both of which are specific for the epidermal growth factor receptor (EGFR), a well-characterized solid tumor antigen. Both scFvs were genetically fused to the SNAP-tag, an engineered version of the human DNA repair enzyme O(6)-alkylguanine DNA alkyltransferase that allows the covalent coupling of benzylguanine (BG)-modified substrates such as fluorescent dyes. The SNAP-tag achieves controllable and irreversible protein modification and is an important tool for experimental studies in vitro and in vivo. The affinity constant of a scFv is a key functional parameter, especially in the context of a fusion protein. Therefore, we developed a method to define the affinity constants of scFv-SNAP fusion proteins by surface plasmon resonance (SPR) spectroscopy. We could confirm that both scFvs retained their functionality after fusion to the SNAP-tag in a variety of procedures and assays, including ELISA, flow cytometry, and confocal microscopy. The experimental procedures described herein, and the new protocol for affinity determination by SPR spectroscopy, are suitable for the preclinical evaluation of diverse antibody formats and derivatives.
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Affiliation(s)
- Judith Niesen
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME , 52074 Aachen, Germany
| | - Markus Sack
- Institute of Molecular Biotechnology (Biology VII), RWTH Aachen University , 52074 Aachen, Germany
| | - Melanie Seidel
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME , 52074 Aachen, Germany
| | - Rolf Fendel
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME , 52074 Aachen, Germany
| | - Stefan Barth
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME , 52074 Aachen, Germany
| | - Rainer Fischer
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME , 52074 Aachen, Germany.,Institute of Molecular Biotechnology (Biology VII), RWTH Aachen University , 52074 Aachen, Germany
| | - Christoph Stein
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME , 52074 Aachen, Germany
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