1
|
Dong L, Liu T, Li J, Wang C, Lv J, Wang J, Wang J, Gao S, Kang L, Xin W. Establishment and Comparison of Detection Methods for Ricin and Abrin Based on Their Depurination Activities. Toxins (Basel) 2025; 17:177. [PMID: 40278675 PMCID: PMC12031163 DOI: 10.3390/toxins17040177] [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: 03/13/2025] [Revised: 03/29/2025] [Accepted: 04/02/2025] [Indexed: 04/26/2025] Open
Abstract
Ricin (RT) and abrin (AT) are plant toxins extracted from Ricinus communis and Abrus precatorius, respectively, and both have N-glycosidase activity. The detection of these toxins is vital because of their accessibility and bioterrorism potential. While ricin can be effectively detected based on its depurination activity, only a few tests are available for detecting the depurination activity of abrin. Therefore, it is unclear whether they share the same optimal reaction substrate and conditions. Here, we established optimum depurination conditions for ricin and abrin, facilitating the in vitro detection of their depurination activity using high-performance liquid chromatography-tandem mass spectrometry. The parameters optimized were the reaction substrate, bovine serum albumin (BSA), buffer, pH, temperature, time, antibodies, and magnetic beads. Both toxins showed better depurination with single-stranded DNA. However, substrate length, adenine content, BSA concentration, buffer concentration, reaction temperature, and reaction time differed between the two toxins. The optimal conditions for ricin depurination involved a reaction in 1 mM ammonium acetate solution (0.5 μM DNA15A, 20 μg/mL BSA, and 1 mM Zn2+, with pH 4.0) at 55 °C for 1 h. The optimal conditions for abrin depurination involved a reaction in 1 mM ammonium citrate solution (0.2 μM DNA20A, 10 μg/mL BSA, 1 mM Mg2+, and 0.5 mM EDTA, with pH 4.0) at 45 °C for 2 h. After optimization, the limits of detection (LOD) for ricin and abrin were 0.506 ng/mL and 0.168 ng/mL, respectively. The detection time was also significantly reduced.
Collapse
Affiliation(s)
- Lina Dong
- School of Basic Medicine, Anhui Medical University, Hefei 230032, China;
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing 100071, China; (T.L.); (J.L.); (J.L.); (J.W.); (J.W.); (S.G.)
| | - Tingting Liu
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing 100071, China; (T.L.); (J.L.); (J.L.); (J.W.); (J.W.); (S.G.)
| | - Jiaxin Li
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing 100071, China; (T.L.); (J.L.); (J.L.); (J.W.); (J.W.); (S.G.)
| | - Cen Wang
- Department of Public Health, School of Public Health and Health Management, Gannan Medical University, Ganzhou City 341000, China;
| | - Jing Lv
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing 100071, China; (T.L.); (J.L.); (J.L.); (J.W.); (J.W.); (S.G.)
| | - Jing Wang
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing 100071, China; (T.L.); (J.L.); (J.L.); (J.W.); (J.W.); (S.G.)
| | - Jinglin Wang
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing 100071, China; (T.L.); (J.L.); (J.L.); (J.W.); (J.W.); (S.G.)
| | - Shan Gao
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing 100071, China; (T.L.); (J.L.); (J.L.); (J.W.); (J.W.); (S.G.)
| | - Lin Kang
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing 100071, China; (T.L.); (J.L.); (J.L.); (J.W.); (J.W.); (S.G.)
| | - Wenwen Xin
- School of Basic Medicine, Anhui Medical University, Hefei 230032, China;
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing 100071, China; (T.L.); (J.L.); (J.L.); (J.W.); (J.W.); (S.G.)
| |
Collapse
|
2
|
Liu ML, Liang XM, Jin MY, Huang HW, Luo L, Wang H, Shen X, Xu ZL. Food-Borne Biotoxin Neutralization in Vivo by Nanobodies: Current Status and Prospects. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:10753-10771. [PMID: 38706131 DOI: 10.1021/acs.jafc.4c02257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
Food-borne biotoxins from microbes, plants, or animals contaminate unclean, spoiled, and rotten foods, posing significant health risks. Neutralizing such toxins is vital for human health, especially after food poisoning. Nanobodies (Nbs), a type of single-domain antibodies derived from the genetic cloning of a variable domain of heavy chain antibodies (VHHs) in camels, offer unique advantages in toxin neutralization. Their small size, high stability, and precise binding enable effective neutralization. The use of Nbs in neutralizing food-borne biotoxins offers numerous benefits, and their genetic malleability allows tailored optimization for diverse toxins. As nanotechnology continues to evolve and improve, Nbs are poised to become increasingly efficient and safer tools for toxin neutralization, playing a pivotal role in safeguarding human health and environmental safety. This review not only highlights the efficacy of these agents in neutralizing toxins but also proposes innovative solutions to address their current challenges. It lays a solid foundation for their further development in this crucial field and propels their commercial application, thereby contributing significantly to advancements in this domain.
Collapse
Affiliation(s)
- Min-Ling Liu
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Xiao-Min Liang
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Ming-Yu Jin
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
- School of Life and Health Technology, Dongguan, University of Technology, Dongguan 523808, China
| | - Hui-Wei Huang
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Lin Luo
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Hong Wang
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Xing Shen
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
| | - Zhen-Lin Xu
- Guangdong Provincial Key Laboratory of Food Quality and Safety/Research Center for Green Development of Agriculture, South China Agricultural University, Guangzhou 510642, China
| |
Collapse
|
3
|
Worbs S, Kampa B, Skiba M, Hansbauer EM, Stern D, Volland H, Becher F, Simon S, Dorner MB, Dorner BG. Differentiation, Quantification and Identification of Abrin and Abrus precatorius Agglutinin. Toxins (Basel) 2021; 13:toxins13040284. [PMID: 33919561 PMCID: PMC8073929 DOI: 10.3390/toxins13040284] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 04/10/2021] [Accepted: 04/13/2021] [Indexed: 12/21/2022] Open
Abstract
Abrin, the toxic lectin from the rosary pea plant Abrus precatorius, has gained considerable interest in the recent past due to its potential malevolent use. However, reliable and easy-to-use assays for the detection and discrimination of abrin from related plant proteins such as Abrus precatorius agglutinin or the homologous toxin ricin from Ricinus communis are sparse. To address this gap, a panel of highly specific monoclonal antibodies was generated against abrin and the related Abrus precatorius agglutinin. These antibodies were used to establish two sandwich ELISAs to preferentially detect abrin or A. precatorius agglutinin (limit of detection 22 pg/mL for abrin; 35 pg/mL for A. precatorius agglutinin). Furthermore, an abrin-specific lateral flow assay was developed for rapid on-site detection (limit of detection ~1 ng/mL abrin). Assays were validated for complex food, environmental and clinical matrices illustrating broad applicability in different threat scenarios. Additionally, the antibodies turned out to be suitable for immuno-enrichment strategies in combination with mass spectrometry-based approaches for unambiguous identification. Finally, we were able to demonstrate for the first time how the developed assays can be applied to detect, identify and quantify abrin from a clinical sample derived from an attempted suicide case involving A. precatorius.
Collapse
Affiliation(s)
- Sylvia Worbs
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany; (S.W.); (B.K.); (M.S.); (E.-M.H.); (D.S.); (M.B.D.)
| | - Bettina Kampa
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany; (S.W.); (B.K.); (M.S.); (E.-M.H.); (D.S.); (M.B.D.)
| | - Martin Skiba
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany; (S.W.); (B.K.); (M.S.); (E.-M.H.); (D.S.); (M.B.D.)
| | - Eva-Maria Hansbauer
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany; (S.W.); (B.K.); (M.S.); (E.-M.H.); (D.S.); (M.B.D.)
- Département Médicaments et Technologies pour la Santé, Université Paris Saclay, CEA, INRAE, SPI, 91191 Gif-sur-Yvette, France; (H.V.); (F.B.); (S.S.)
| | - Daniel Stern
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany; (S.W.); (B.K.); (M.S.); (E.-M.H.); (D.S.); (M.B.D.)
| | - Hervé Volland
- Département Médicaments et Technologies pour la Santé, Université Paris Saclay, CEA, INRAE, SPI, 91191 Gif-sur-Yvette, France; (H.V.); (F.B.); (S.S.)
| | - François Becher
- Département Médicaments et Technologies pour la Santé, Université Paris Saclay, CEA, INRAE, SPI, 91191 Gif-sur-Yvette, France; (H.V.); (F.B.); (S.S.)
| | - Stéphanie Simon
- Département Médicaments et Technologies pour la Santé, Université Paris Saclay, CEA, INRAE, SPI, 91191 Gif-sur-Yvette, France; (H.V.); (F.B.); (S.S.)
| | - Martin B. Dorner
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany; (S.W.); (B.K.); (M.S.); (E.-M.H.); (D.S.); (M.B.D.)
| | - Brigitte G. Dorner
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany; (S.W.); (B.K.); (M.S.); (E.-M.H.); (D.S.); (M.B.D.)
- Correspondence: ; Tel.: +49-30-18754-2500
| |
Collapse
|
4
|
|
5
|
Mechaly A, Alcalay R, Noy-Porat T, Epstein E, Gal Y, Mazor O. Novel Phage Display-Derived Anti-Abrin Antibodies Confer Post-Exposure Protection against Abrin Intoxication. Toxins (Basel) 2018; 10:toxins10020080. [PMID: 29438273 PMCID: PMC5848181 DOI: 10.3390/toxins10020080] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/06/2018] [Accepted: 02/08/2018] [Indexed: 11/20/2022] Open
Abstract
Abrin toxin is a type 2 ribosome inactivating glycoprotein isolated from the seeds of Abrus precatorius (jequirity pea). Owing to its high toxicity, relative ease of purification and accessibility, it is considered a biological threat agent. To date, there is no effective post-exposure treatment for abrin poisoning and passive immunization remains the most effective therapy. However, the effectiveness of anti-abrin monoclonal antibodies for post-exposure therapy following abrin intoxication has not been demonstrated. The aim of this study was to isolate high affinity anti-abrin antibodies that possess potent toxin-neutralization capabilities. An immune scFv phage-display library was constructed from an abrin-immunized rabbit and a panel of antibodies (six directed against the A subunit of abrin and four against the B subunit) was isolated and expressed as scFv-Fc antibodies. By pair-wise analysis, we found that these antibodies target five distinct epitopes on the surface of abrin and that antibodies against all these sites can bind the toxin simultaneously. Several of these antibodies (namely, RB9, RB10, RB28 and RB30) conferred high protection against pulmonary intoxication of mice, when administered six hours post exposure to a lethal dose of abrin. The data presented in this study demonstrate for the first time the efficacy of monoclonal antibodies in treatment of mice after pulmonary intoxication with abrin and promote the use of these antibodies, one or several, for post-exposure treatment of abrin intoxication.
Collapse
Affiliation(s)
- Adva Mechaly
- Department of Infectious Diseases, Israel Institute for Biological Research, Ness-Ziona 76100, Israel;
| | - Ron Alcalay
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (R.A.); (T.N.-P.); (Y.G.)
| | - Tal Noy-Porat
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (R.A.); (T.N.-P.); (Y.G.)
| | - Eyal Epstein
- Department of Biotechnology, Israel Institute for Biological Research, Ness-Ziona 76100, Israel;
| | - Yoav Gal
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona 76100, Israel; (R.A.); (T.N.-P.); (Y.G.)
| | - Ohad Mazor
- Department of Infectious Diseases, Israel Institute for Biological Research, Ness-Ziona 76100, Israel;
- Correspondence: ; Tel.: +972-8-938-5862; Fax: +972-8-938-1544
| |
Collapse
|
6
|
He X, Patfield S, Cheng LW, Stanker LH, Rasooly R, McKeon TA, Zhang Y, Brandon DL. Detection of Abrin Holotoxin Using Novel Monoclonal Antibodies. Toxins (Basel) 2017; 9:E386. [PMID: 29182545 PMCID: PMC5744106 DOI: 10.3390/toxins9120386] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 11/09/2017] [Accepted: 11/23/2017] [Indexed: 01/17/2023] Open
Abstract
Abrin, a member of the ribosome-inactivating protein family, is produced by the Abrus precatorius plant. Having the potential to pose a severe threat to both human and animal health, abrin is classified as a Select Agent by the U.S. Department of Health and Human Services. However, an immunoassay that is specific for intact abrin holotoxin has not yet been reported. In this study, seven new monoclonal antibodies (mAbs), designated as Abrin-1 through Abrin-7 have been developed. Isotyping analyses indicate these mAbs have IgG1, IgG2a, or IgG2b heavy-chains and kappa light-chains. Western blot analyses identified two abrin A-chain specific mAbs, Abrin-1 and Abrin-2, and four B-chain specific mAbs (Abrin-3, -5, -6, and -7). A sandwich enzyme-linked immunosorbent assay (ELISA), capable of detecting a mixture of abrin isoforms and agglutinins was developed using B-chain specific Abrin-3 for capture and A-chain specific Abrin-2 as detector. The ELISA is highly sensitive and detects 1 ng/mL of the abrin holotoxin in phosphate-buffered saline, nonfat milk, and whole milk, significantly below concentrations that would pose a health concern for consumers. This ELISA also detects native abrin in plant extracts with a very low background signal. The new abrin mAbs and ELISA should be useful for detecting this potent toxin in the milk supply chain and other complex matrices.
Collapse
Affiliation(s)
- Xiaohua He
- Western Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, CA 94710, USA.
| | - Stephanie Patfield
- Western Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, CA 94710, USA.
| | - Luisa W Cheng
- Western Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, CA 94710, USA.
| | - Larry H Stanker
- Western Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, CA 94710, USA.
| | - Reuven Rasooly
- Western Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, CA 94710, USA.
| | - Thomas A McKeon
- Western Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, CA 94710, USA.
| | - Yuzhu Zhang
- Western Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, CA 94710, USA.
| | - David L Brandon
- Western Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, CA 94710, USA.
| |
Collapse
|
7
|
Abrin Toxicity and Bioavailability after Temperature and pH Treatment. Toxins (Basel) 2017; 9:toxins9100320. [PMID: 29027937 PMCID: PMC5666367 DOI: 10.3390/toxins9100320] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/07/2017] [Accepted: 10/10/2017] [Indexed: 11/17/2022] Open
Abstract
Abrin, one of most potent toxins known to man, is derived from the rosary pea (jequirity pea), Abrus precatorius and is a potential bioterror weapon. The temperature and pH stability of abrin was evaluated with an in vitro cell free translation (CFT) assay, a Vero cell culture cytotoxicity assay, and an in vivo mouse bioassay. pH treatment of abrin had no detrimental effect on its stability and toxicity as seen either in vitro or in vivo. Abrin exposure to increasing temperatures did not completely abrogate protein translation. In both the cell culture cytotoxicity model and the mouse bioassay, abrin’s toxic effects were completely abrogated if the toxin was exposed to temperatures of 74 °C or higher. In the cell culture model, 63 °C-treated abrin had a 30% reduction in cytotoxicity which was validated in the in vivo mouse bioassay with all mice dying but with a slight time-to-death delay as compared to the non-treated abrin control. Since temperature inactivation did not affect abrin’s ability to inhibit protein synthesis (A-chain), we hypothesize that high temperature treatment affected abrin’s ability to bind to cellular receptors (affecting B-chain). Our results confirm the absolute need to validate in vitro cytotoxicity assays with in vivo mouse bioassays.
Collapse
|
8
|
Sant B, Rao PVL, Nagar DP, Pant SC, Bhasker ASB. Evaluation of abrin induced nephrotoxicity by using novel renal injury markers. Toxicon 2017; 131:20-28. [PMID: 28288935 DOI: 10.1016/j.toxicon.2017.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 12/22/2022]
Abstract
Abrin is a potent plant toxin analogous to ricin that is derived from the seeds of Abrus precatorius plant. It belongs to the family of type II ribosome-inactivating proteins and causes cell death by irreversibly inactivating ribosomes through site-specific depurination. In this study we examined the in vivo nephrotoxicity potential of abrin toxin in terms of oxidative stress, inflammation, histopathological changes and biomarkers of kidney injury. Animals were exposed to 0.5 and 1.0 LD50 dose of abrin by intraperitoneal route and observed for 1, 3, and 7 day post-toxin exposure. Depletion of reduced glutathione and increased lipid peroxidation levels were observed in abrin treated mice. In addition, abrin also induced inflammation in the kidneys as observed through expression of MMP-9 and MMP-9/NGAL complex in abrin treated groups by using zymography method. Nephrotoxicity was also evaluated by western blot analysis of kidney injury biomarkers including Clusterin, Cystatin C and NGAL, and their results indicate severity of kidney injury in abrin treated groups. Kidney histology confirmed inflammatory changes due to abrin. The data generated in the present study clearly prove the nephrotoxicity potential of abrin.
Collapse
Affiliation(s)
- Bhavana Sant
- Division of Pharmacology and Toxicology, Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India
| | - P V Lakshmana Rao
- Division of Pharmacology and Toxicology, Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India
| | - D P Nagar
- Division of Pharmacology and Toxicology, Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India
| | - S C Pant
- Division of Pharmacology and Toxicology, Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India
| | - A S B Bhasker
- Division of Pharmacology and Toxicology, Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India.
| |
Collapse
|
9
|
Sarkes DA, Hurley MM, Stratis-Cullum DN. Unraveling the Roots of Selectivity of Peptide Affinity Reagents for Structurally Similar Ribosomal Inactivating Protein Derivatives. Molecules 2016; 21:E1504. [PMID: 27834872 PMCID: PMC6272918 DOI: 10.3390/molecules21111504] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 11/02/2016] [Accepted: 11/04/2016] [Indexed: 11/17/2022] Open
Abstract
Peptide capture agents have become increasingly useful tools for a variety of sensing applications due to their ease of discovery, stability, and robustness. Despite the ability to rapidly discover candidates through biopanning bacterial display libraries and easily mature them to Protein Catalyzed Capture (PCC) agents with even higher affinity and selectivity, an ongoing challenge and critical selection criteria is that the peptide candidates and final reagent be selective enough to replace antibodies, the gold-standard across immunoassay platforms. Here, we have discovered peptide affinity reagents against abrax, a derivative of abrin with reduced toxicity. Using on-cell Fluorescence Activated Cell Sorting (FACS) assays, we show that the peptides are highly selective for abrax over RiVax, a similar derivative of ricin originally designed as a vaccine, with significant structural homology to abrax. We rank the newly discovered peptides for strongest affinity and analyze three observed consensus sequences with varying affinity and specificity. The strongest (Tier 1) consensus was FWDTWF, which is highly aromatic and hydrophobic. To better understand the observed selectivity, we use the XPairIt peptide-protein docking protocol to analyze binding location predictions of the individual Tier 1 peptides and consensus on abrax and RiVax. The binding location profiles on the two proteins are quite distinct, which we determine is due to differences in pocket size, pocket environment (including hydrophobicity and electronegativity), and steric hindrance. This study provides a model system to show that peptide capture candidates can be quite selective for a structurally similar protein system, even without further maturation, and offers an in silico method of analysis for understanding binding and down-selecting candidates.
Collapse
Affiliation(s)
- Deborah A Sarkes
- Biotechnology Branch, Sensors and Electron Devices Directorate, US Army Research Laboratory, Adelphi, MD 20783, USA.
| | - Margaret M Hurley
- Biotechnology Branch, Sensors and Electron Devices Directorate, US Army Research Laboratory, Adelphi, MD 20783, USA.
| | - Dimitra N Stratis-Cullum
- Biotechnology Branch, Sensors and Electron Devices Directorate, US Army Research Laboratory, Adelphi, MD 20783, USA.
| |
Collapse
|
10
|
Wooten JV, Pittman CT, Blake TA, Thomas JD, Devlin JJ, Higgerson RA, Johnson RC. A case of abrin toxin poisoning, confirmed via quantitation of L-abrine (N-methyl-L-tryptophan) biomarker. J Med Toxicol 2015; 10:392-4. [PMID: 24522983 DOI: 10.1007/s13181-013-0377-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
INTRODUCTION The seeds of Abrus precatorius contain the highly toxic plant protein abrin. There is no antidote for abrin poisoning. Management, largely supportive, may consist of administering intravenous fluids, anti-emetics, and activated charcoal depending on the time of exposure. We report the presentation of a single case of unintentional abrin poisoning confirmed by the quantitation of L-abrine biomarker. CASE REPORT A previously healthy 22-month-old, 11.5-kg female presented to the hospital after ingesting approximately 20 rosary peas (A. precatorius) sold as a "peace bracelet". Her primary manifestations were episodes of forceful emesis that included food particles progressing to clear gastric fluid. The patient was tachycardic (HR = 134 bpm) but had brisk capillary refill and normal blood pressure (96/60 mmHg). Laboratory testing revealed elevated blood urea nitrogen (16 mg/dL) and serum creatinine (0.4 mg/dL). In the emergency department, the patient was resuscitated with 40 mL/kg normal saline via peripheral IV and received ondansetron (0.15 mg/kg IV) to control retching. The patient was discharged well 24 h after the ingestion. DISCUSSION This is the first case of human abrin toxin poisoning confirmed by the quantitation of L-abrine as a biomarker. Quantifying the levels of abrin toxin in the body after exposure can help clinicians make informed decisions when managing patients with symptomatic exposures to seeds of A. precatorius.
Collapse
Affiliation(s)
- Joe Valentine Wooten
- National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA,
| | | | | | | | | | | | | |
Collapse
|
11
|
Kim DY, To R, Kandalaft H, Ding W, van Faassen H, Luo Y, Schrag JD, St-Amant N, Hefford M, Hirama T, Kelly JF, MacKenzie R, Tanha J. Antibody light chain variable domains and their biophysically improved versions for human immunotherapy. MAbs 2014; 6:219-35. [PMID: 24423624 PMCID: PMC3929445 DOI: 10.4161/mabs.26844] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We set out to gain deeper insight into the potential of antibody light chain variable domains (VLs) as immunotherapeutics. To this end, we generated a naïve human VL phage display library and, by using a method previously shown to select for non-aggregating antibody heavy chain variable domains (VHs), we isolated a diversity of VL domains by panning the library against B cell super-antigen protein L. Eight domains representing different germline origins were shown to be non-aggregating at concentrations as high as 450 µM, indicating VL repertoires are a rich source of non-aggregating domains. In addition, the VLs demonstrated high expression yields in E. coli, protein L binding and high reversibility of thermal unfolding. A side-by-side comparison with a set of non-aggregating human VHs revealed that the VLs had similar overall profiles with respect to melting temperature (Tm), reversibility of thermal unfolding and resistance to gastrointestinal proteases. Successful engineering of a non-canonical disulfide linkage in the core of VLs did not compromise the non-aggregation state or protein L binding properties. Furthermore, the introduced disulfide bond significantly increased their Tms, by 5.5–17.5 °C, and pepsin resistance, although it somewhat reduced expression yields and subtly changed the structure of VLs. Human VLs and engineered versions may make suitable therapeutics due to their desirable biophysical features. The disulfide linkage-engineered VLs may be the preferred therapeutic format because of their higher stability, especially for oral therapy applications that necessitate high resistance to the stomach’s acidic pH and pepsin.
Collapse
Affiliation(s)
- Dae Young Kim
- Human Health Therapeutics; National Research Council Canada; Ottawa, ON Canada
| | - Rebecca To
- Human Health Therapeutics; National Research Council Canada; Ottawa, ON Canada
| | - Hiba Kandalaft
- Human Health Therapeutics; National Research Council Canada; Ottawa, ON Canada
| | - Wen Ding
- Human Health Therapeutics; National Research Council Canada; Ottawa, ON Canada
| | - Henk van Faassen
- Human Health Therapeutics; National Research Council Canada; Ottawa, ON Canada
| | - Yan Luo
- Human Health Therapeutics; National Research Council Canada; Ottawa, ON Canada
| | - Joseph D Schrag
- Human Health Therapeutics; National Research Council Canada; Montréal, QC Canada
| | - Nadereh St-Amant
- Centre for Vaccine Evaluation; Biologics and Genetic Therapies Directorate;, Health Canada; Ottawa, ON Canada
| | - Mary Hefford
- Centre for Vaccine Evaluation; Biologics and Genetic Therapies Directorate;, Health Canada; Ottawa, ON Canada
| | - Tomoko Hirama
- Human Health Therapeutics; National Research Council Canada; Ottawa, ON Canada
| | - John F Kelly
- Human Health Therapeutics; National Research Council Canada; Ottawa, ON Canada
| | - Roger MacKenzie
- Human Health Therapeutics; National Research Council Canada; Ottawa, ON Canada; School of Environmental Sciences; Ontario Agricultural College; University of Guelph; Guelph, ON Canada
| | - Jamshid Tanha
- Human Health Therapeutics; National Research Council Canada; Ottawa, ON Canada; School of Environmental Sciences; Ontario Agricultural College; University of Guelph; Guelph, ON Canada; Department of Biochemistry, Microbiology, and Immunology; University of Ottawa; Ottawa, ON Canada
| |
Collapse
|
12
|
Walper SA, Liu JL, Zabetakis D, Anderson GP, Goldman ER. Development and evaluation of single domain antibodies for vaccinia and the L1 antigen. PLoS One 2014; 9:e106263. [PMID: 25211488 PMCID: PMC4161341 DOI: 10.1371/journal.pone.0106263] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 07/30/2014] [Indexed: 11/25/2022] Open
Abstract
There is ongoing interest to develop high affinity, thermal stable recognition elements to replace conventional antibodies in biothreat detection assays. As part of this effort, single domain antibodies that target vaccinia virus were developed. Two llamas were immunized with killed viral particles followed by boosts with the recombinant membrane protein, L1, to stimulate the immune response for envelope and membrane proteins of the virus. The variable domains of the induced heavy chain antibodies were selected from M13 phage display libraries developed from isolated RNA. Selection via biopanning on the L1 antigen produced single domain antibodies that were specific and had affinities ranging from 4×10−9 M to 7.0×10−10 M, as determined by surface plasmon resonance. Several showed good ability to refold after heat denaturation. These L1-binding single domain antibodies, however, failed to recognize the killed vaccinia antigen. Useful vaccinia binding single domain antibodies were isolated by a second selection using the killed virus as the target. The virus binding single domain antibodies were incorporated in sandwich assays as both capture and tracer using the MAGPIX system yielding limits of detection down to 4×105 pfu/ml, a four-fold improvement over the limit obtained using conventional antibodies. This work demonstrates the development of anti-vaccinia single domain antibodies and their incorporation into sandwich assays for viral detection. It also highlights the properties of high affinity and thermal stability that are hallmarks of single domain antibodies.
Collapse
Affiliation(s)
- Scott A. Walper
- Naval Research Laboratory, Center for Bio/Molecular Science and Engineering, Washington, DC, United States of America
| | - Jinny L. Liu
- Naval Research Laboratory, Center for Bio/Molecular Science and Engineering, Washington, DC, United States of America
| | - Daniel Zabetakis
- Naval Research Laboratory, Center for Bio/Molecular Science and Engineering, Washington, DC, United States of America
| | - George P. Anderson
- Naval Research Laboratory, Center for Bio/Molecular Science and Engineering, Washington, DC, United States of America
| | - Ellen R. Goldman
- Naval Research Laboratory, Center for Bio/Molecular Science and Engineering, Washington, DC, United States of America
- * E-mail:
| |
Collapse
|
13
|
Turner KB, Zabetakis D, Legler P, Goldman ER, Anderson GP. Isolation and epitope mapping of staphylococcal enterotoxin B single-domain antibodies. SENSORS (BASEL, SWITZERLAND) 2014; 14:10846-63. [PMID: 24949641 PMCID: PMC4118376 DOI: 10.3390/s140610846] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 06/09/2014] [Accepted: 06/10/2014] [Indexed: 12/22/2022]
Abstract
Single-domain antibodies (sdAbs), derived from the heavy chain only antibodies found in camelids such as llamas have the potential to provide rugged detection reagents with high affinities, and the ability to refold after denaturation. We have isolated and characterized sdAbs specific to staphylococcal enterotoxin B (SEB) which bind to two distinct epitopes and are able to function in a sandwich immunoassay for toxin detection. Characterization of these sdAbs revealed that each exhibited nanomolar binding affinities or better. Melting temperatures for the sdAbs ranged from approximately 60 °C to over 70 °C, with each demonstrating at least partial refolding after denaturation and several were able to completely refold. A first set of sdAbs was isolated by panning the library using adsorbed antigen, all of which recognized the same epitope on SEB. Epitope mapping suggested that these sdAbs bind to a particular fragment of SEB (VKSIDQFLYFDLIYSI) containing position L45 (underlined), which is involved in binding to the major histocompatibility complex (MHC). Differences in the binding affinities of the sdAbs to SEB and a less-toxic vaccine immunogen, SEBv (L45R/Y89A/Y94A) were also consistent with binding to this epitope. A sandwich panning strategy was utilized to isolate sdAbs which bind a second epitope. This epitope differed from the initial one obtained or from that recognized by previously isolated anti-SEB sdAb A3. Using SEB-toxin spiked milk we demonstrated that these newly isolated sdAbs could be utilized in sandwich-assays with each other, A3, and with various monoclonal antibodies.
Collapse
Affiliation(s)
- Kendrick B Turner
- American Society for Engineering Education, Postdoctoral Fellow at the Naval Research Laboratory, Washington, DC 20375, USA.
| | - Dan Zabetakis
- Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA.
| | - Patricia Legler
- Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA.
| | - Ellen R Goldman
- Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA.
| | - George P Anderson
- Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA.
| |
Collapse
|
14
|
Turner KB, Zabetakis D, Goldman ER, Anderson GP. Enhanced stabilization of a stable single domain antibody for SEB toxin by random mutagenesis and stringent selection. Protein Eng Des Sel 2014; 27:89-95. [PMID: 24488977 DOI: 10.1093/protein/gzu001] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Single domain antibodies, recombinant variable heavy domains derived from the unique heavy-chain only antibodies found in camelids and sharks, are exceptionally rugged due to their ability to refold following heat or chemical denaturation. In addition, a number of single domain antibodies have been found to possess high melting points which provide an even greater degree of stability; one of these, llama-derived A3, is a binder of Staphylococcal enterotoxin B and has a Tm of 83.5 °C. In this work, we utilized random mutagenesis and stringent selection in an effort to obtain variants of A3 with even higher melting points. This effort resulted in the selection of a double mutant, A3-T28I-S72I, which has a melting point of 90.0 °C and near wild-type affinity for the target antigen. We further characterized the mutations individually to determine that while both contributed to the thermal stabilization, the T28I mutation accounted for ∼ 4.1 °C of the 6.5 °C increase. This work demonstrates that by the addition of relatively subtle changes it is possible to further improve the melting temperature of single domain antibodies that are already remarkably stable.
Collapse
Affiliation(s)
- Kendrick B Turner
- American Society for Engineering Education Postdoctoral Fellow, Naval Research Laboratory, Washington, DC 20375, USA
| | | | | | | |
Collapse
|
15
|
Goldman ER, Brozozog-Lee PA, Zabetakis D, Turner KB, Walper SA, Liu JL, Anderson GP. Negative tail fusions can improve ruggedness of single domain antibodies. Protein Expr Purif 2014; 95:226-32. [PMID: 24440507 DOI: 10.1016/j.pep.2014.01.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 01/06/2014] [Accepted: 01/08/2014] [Indexed: 12/31/2022]
Abstract
Single-domain antibodies (sdAbs), the recombinantly expressed binding domains derived from the heavy-chain-only antibodies found in camelids and sharks, are valued for their ability to refold after heat denaturation. However, some sdAbs are prone to aggregation on extended heating at high concentration. Additionally, sdAbs prepared cytoplasmically often lack the conserved disulfide bond found in variable heavy domains, which both decreases their melting point and can decrease their ability to refold. Genetic fusions of sdAbs with the acid tail of α-synuclein (ATS) resulted in constructs that had enhanced ability to resist aggregation. In addition, almost complete refolding was observed even in the absence of the disulfide bond. These sdAb-ATS fusions expand the utility of sdAbs. They provide sdAbs that are resistant to aggregation, and enable the production of re-foldable sdAbs in the reducing environment of the cytoplasm.
Collapse
Affiliation(s)
- Ellen R Goldman
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375, USA
| | | | - Dan Zabetakis
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375, USA
| | - Kendrick B Turner
- Science and Engineering Apprenticeship Program, American Society for Engineering Education, 4555 Overlook Ave. SW, Washington, DC 20375, USA
| | - Scott A Walper
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375, USA
| | - Jinny L Liu
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375, USA
| | - George P Anderson
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375, USA.
| |
Collapse
|
16
|
Contributions of the complementarity determining regions to the thermal stability of a single-domain antibody. PLoS One 2013; 8:e77678. [PMID: 24143255 PMCID: PMC3797041 DOI: 10.1371/journal.pone.0077678] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 09/03/2013] [Indexed: 11/19/2022] Open
Abstract
Single domain antibodies (sdAbs) are the recombinantly-expressed variable domain from camelid (or shark) heavy chain only antibodies and provide rugged recognition elements. Many sdAbs possess excellent affinity and specificity; most refold and are able to bind antigen after thermal denaturation. The sdAb A3, specific for the toxin Staphylococcal enterotoxin B (SEB), shows both sub-nanomolar affinity for its cognate antigen (0.14 nM) and an unusually high melting point of 85°C. Understanding the source of sdAb A3's high melting temperature could provide a route for engineering improved melting temperatures into other sdAbs. The goal of this work was to determine how much of sdAb A3's stability is derived from its complementarity determining regions (CDRs) versus its framework. Towards answering this question we constructed a series of CDR swap mutants in which the CDRs from unrelated sdAbs were integrated into A3's framework and where A3's CDRs were integrated into the framework of the other sdAbs. All three CDRs from A3 were moved to the frameworks of sdAb D1 (a ricin binder that melts at 50°C) and the anti-ricin sdAb C8 (melting point of 60°C). Similarly, the CDRs from sdAb D1 and sdAb C8 were moved to the sdAb A3 framework. In addition individual CDRs of sdAb A3 and sdAb D1 were swapped. Melting temperature and binding ability were assessed for each of the CDR-exchange mutants. This work showed that CDR2 plays a critical role in sdAb A3's binding and stability. Overall, results from the CDR swaps indicate CDR interactions play a major role in the protein stability.
Collapse
|
17
|
Legler PM, Zabetakis D, Anderson GP, Lam A, Hol WGJ, Goldman ER. Structure of a low-melting-temperature anti-cholera toxin: llama V(H)H domain. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:90-3. [PMID: 23385744 DOI: 10.1107/s1744309112050750] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 12/13/2012] [Indexed: 01/29/2023]
Abstract
Variable heavy domains derived from the heavy-chain-only antibodies found in camelids (V(H)H domains) are known for their thermal stability. Here, the structure of A9, an anti-cholera toxin V(H)H domain (K(d) = 77 ± 5 nM) that has an unusually low melting temperature of 319.9 ± 1.6 K, is reported. The CDR3 residues of A9 form a β-hairpin that is directed away from the former V(H)-V(L) interfacial surface, exposing hydrophobic residues to the solvent. A DALI structural similarity search showed that this CDR3 conformation is uncommon.
Collapse
Affiliation(s)
- Patricia M Legler
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA.
| | | | | | | | | | | |
Collapse
|