1
|
|
2
|
Hughes AC, Patfield S, Rasooly R, He X. Validation of a Cell-Based Assay for Detection of Active Shiga Toxins Produced by Escherichia coli in Water. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17217901. [PMID: 33126550 PMCID: PMC7663042 DOI: 10.3390/ijerph17217901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 10/20/2020] [Accepted: 10/20/2020] [Indexed: 11/16/2022]
Abstract
Shiga toxin-producing Escherichia coli (STEC) causes a wide spectrum of diseases, including hemorrhagic colitis and hemolytic uremic syndrome (HUS). Almost 5% of STEC infections result from waterborne exposures, yet there is no test listed in the EPA's current Selected Analytical Methods for the detection of active Shiga toxins (Stxs) in water. In this study, a HeLa cell-based assay is validated for the detection of metabolically active Stxs produced by STEC in water, including tap, bottled, and pond water. Active Stxs are detected even when the number of Stx-producing bacteria is less than 0.4 CFU/mL and the assay performance is not affected by background flora or chlorine in the water. This assay is not only as simple and affordable as cell-free assays but also detects active holotoxins without the use of live animals. In addition, the assay is designed for use in multi-well formats, making it ideal for high-throughput screening of water samples and therefore useful for environmental public health surveillance programs to reduce human risk of infection with STEC.
Collapse
Affiliation(s)
- Anna C. Hughes
- Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, 800 Buchanan St., Albany, CA 94710, USA; (A.C.H.); (S.P.); (R.R.)
| | - Stephanie Patfield
- Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, 800 Buchanan St., Albany, CA 94710, USA; (A.C.H.); (S.P.); (R.R.)
- Forensic Services Division, Contra Costa County Office of the Sheriff, 651 Pine St., Martinez, CA 94553, USA
| | - Reuven Rasooly
- Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, 800 Buchanan St., Albany, CA 94710, USA; (A.C.H.); (S.P.); (R.R.)
| | - Xiaohua He
- Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, 800 Buchanan St., Albany, CA 94710, USA; (A.C.H.); (S.P.); (R.R.)
- Correspondence: ; Tel.: +1-(510)-559-5823
| |
Collapse
|
3
|
Liu CC, Liang LH, Yang Y, Yu HL, Yan L, Li XS, Chen B, Liu SL, Xi HL. Direct Acetonitrile-Assisted Trypsin Digestion Method Combined with LC-MS/MS-Targeted Peptide Analysis for Unambiguous Identification of Intact Ricin. J Proteome Res 2020; 20:369-380. [PMID: 33108200 DOI: 10.1021/acs.jproteome.0c00458] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ricin is a type II ribosome-inactivating protein toxin consisting of A and B chains linked by one interchain disulfide bond. Because of its high toxicity depending on both chains together, confirming the presence of both A and B chains of intact ricin is required during the investigation of the illegal production and application. Here, we report a novel and sensitive acetonitrile (ACN)-assisted trypsin digestion method for unambiguous identification of intact ricin by simultaneous detection of its marker peptides from A and B chains. Marker peptides were generated with a simple procedure by direct cleaving the native ricin at 45 °C for 4 h using Promega modified sequencing grade trypsin under the assistance of 10% ACN, and then directly analyzed by ultrahigh performance liquid chromatography tandem mass spectrometry. The type of trypsin was found to be one critical factor for cleavage of intact ricin based on a significant difference in the yields of specific peptides generated while using various types of trypsin. A low content of ACN in enzymatic buffer significantly reduced the digestion time from overnight to 4 h. There was commonly a better MS response of marker peptides when using the developed ACN-assisted trypsin digestion method than methanol-assisted trypsin digestion within the same 4 h. Totally, seven specific peptides with high sensitivity and specificity including three in the A-chain (TA7, TA11, and TA10) and four in the B-chain (TB6, TB14-ss-TB16, TB20, and TB18) were obtained as good marker peptides for unambiguous identification of intact ricin. The lowest concentration of native ricin for unambiguous identification was 20 ng/mL, in which three marker peptides from both the A-chain and B-chain could be measured with a minimum of three ion transitions. Combined with affinity enrichment, the developed approach was successfully applied for the measurement of intact ricin from the complicated matrix samples of the second, third, and fourth biotoxin exercises organized by the Organisation for the Prohibition of Chemical Weapons (OPCW). This study has provided a recommended detection method combined with one novel ACN-assisted trypsin digestion with MS for forensic unambiguous confirmation of trace ricin intact with high confidence.
Collapse
Affiliation(s)
- Chang-Cai Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.,Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing 102205, China
| | - Long-Hui Liang
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China
| | - Yang Yang
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.,Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing 102205, China
| | - Hui-Lan Yu
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.,Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing 102205, China
| | - Long Yan
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.,Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing 102205, China
| | - Xiao-Sen Li
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.,Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing 102205, China
| | - Bo Chen
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China
| | - Shi-Lei Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.,Laboratory of Analytical Chemistry, Research Institute of Chemical Defence, Beijing 102205, China
| | - Hai-Ling Xi
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China
| |
Collapse
|
4
|
Franke H, Scholl R, Aigner A. Ricin and Ricinus communis in pharmacology and toxicology-from ancient use and "Papyrus Ebers" to modern perspectives and "poisonous plant of the year 2018". Naunyn Schmiedebergs Arch Pharmacol 2019; 392:1181-1208. [PMID: 31359089 DOI: 10.1007/s00210-019-01691-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 07/04/2019] [Indexed: 12/19/2022]
Abstract
While probably originating from Africa, the plant Ricinus communis is found nowadays around the world, grown for industrial use as a source of castor oil production, wildly sprouting in many regions, or used as ornamental plant. As regards its pharmacological utility, a variety of medical purposes of selected parts of the plant, e.g., as a laxative, an anti-infective, or an anti-inflammatory drug, have been described already in the sixteenth century BC in the famous Papyrus Ebers (treasured in the Library of the University of Leipzig). Quite in contrast, on the toxicological side, the native plant has become the "poisonous plant 2018" in Germany. As of today, a number of isolated components of the plant/seeds have been characterized, including, e.g., castor oil, ricin, Ricinus communis agglutinin, ricinin, nudiflorin, and several allergenic compounds. This review mainly focuses on the most toxic protein, ricin D, classified as a type 2 ribosome-inactivating protein (RIP2). Ricin is one of the most potent and lethal substances known. It has been considered as an important bioweapon (categorized as a Category B agent (second-highest priority)) and an attractive agent for bioterroristic activities. On the other hand, ricin presents great potential, e.g., as an anti-cancer agent or in cell-based research, and is even explored in the context of nanoparticle formulations in tumor therapy. This review provides a comprehensive overview of the pharmacology and toxicology-related body of knowledge on ricin. Toxicokinetic/toxicodynamic aspects of ricin poisoning and possibilities for analytical detection and therapeutic use are summarized as well.
Collapse
Affiliation(s)
- Heike Franke
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, Medical Faculty, University of Leipzig, Haertelstrasse 16-18, 04107, Leipzig, Germany.
| | - Reinhold Scholl
- Department of History, University of Leipzig, Leipzig, Germany
| | - Achim Aigner
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, Clinical Pharmacology, Medical Faculty, University of Leipzig, Leipzig, Germany
| |
Collapse
|
5
|
Andrade IRAD, Cândido MJD, Pompeu RCFF, Feitosa TS, Bomfim MAD, Salles HO, Egito ASD. Inactivation of lectins from castor cake by alternative chemical compounds. Toxicon 2019; 160:47-54. [PMID: 30790577 DOI: 10.1016/j.toxicon.2019.02.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 02/03/2019] [Indexed: 10/27/2022]
Abstract
Enabling the use of castor cake in animal feeding is an excellent alternative strategy to reduce feed costs. The cake is a by-product derived from the extraction of the castor oil by the biodiesel industry whose chemical composition is satisfactory despite the presence of antinutritional factors like toxic lectins, which require detoxification before it can be used as a dietary ingredient. The aim of the present study was to evaluate alternative chemical sources in the degradation and inactivation of ricin and Ricinus communis agglutinin (RCA), two lectins from castor cake. Ten chemical compounds were evaluated: sodium hydroxide, monodicalcium phosphate, dicalcium phosphate, calcium oxide, calcium hydroxide, calcitic limestone, magnesian limestone, urea, potassium chloride, and sodium chloride. Gel electrophoresis indicated 100% lectin degradation only in the cakes treated with 90 g sodium hydroxide and 2500 mL water per kg of cake. The hemagglutination assay was crucial to providing innocuousness to the treated cakes, with total absence of hemagglutinating activity observed in the castor cakes treated with 60 or 90 g sodium hydroxide in water volumes equal to or higher than 1500 mL/kg of castor cake and in the cakes treated with 90 g calcium oxide with 2500 or 3000 mL water/kg castor cake. Thus, though depending on the concentration of the chemical compound and on the volume of water per kilogram of treated cake, sodium hydroxide and calcium oxide showed to be promising chemical products for degradation and complete inactivation of the lectins present in castor cake to allow its use as an ingredient in animal diets.
Collapse
Affiliation(s)
- Igo Renan Albuquerque de Andrade
- Instituto Federal de Educação, Ciência e Tecnologia do Ceará/IFCE, Campus Crateús, Av. Geraldo Marques Barbosa, 567, 63708-260, Crateús, CE, Brazil.
| | - Magno José Duarte Cândido
- Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Zootecnia, Av. Mister Hull, 2977, Bl. 808, Pici Campus, 60440-554, Fortaleza, CE, Brazil.
| | | | - Tibério Sousa Feitosa
- Departamento de Zootecnia, ESALQ, Universidade de São Paulo, Avenida Pádua Dias, 11, 13418-900, Piracicaba, SP, Brazil
| | | | - Hévila Oliveira Salles
- Embrapa Caprinos e Ovinos, Estrada Sobral - Groaíras, Km 04, PO Box 71, 62010-970, Sobral, CE, Brazil
| | - Antonio Silvio do Egito
- Embrapa Caprinos e Ovinos/Núcleo Regional Nordeste, Rua Oswaldo Cruz, n° 1.143, Bairro Centenário, 58.428-095, Campina Grande, PB, Brazil.
| |
Collapse
|
6
|
Cai Z, Sasmal A, Liu X, Asher SA. Responsive Photonic Crystal Carbohydrate Hydrogel Sensor Materials for Selective and Sensitive Lectin Protein Detection. ACS Sens 2017; 2:1474-1481. [PMID: 28934853 DOI: 10.1021/acssensors.7b00426] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Lectin proteins, such as the highly toxic lectin protein, ricin, and the immunochemically important lectin, jacalin, play significant roles in many biological functions. It is highly desirable to develop a simple but efficient method to selectively detect lectin proteins. Here we report the development of carbohydrate containing responsive hydrogel sensing materials for the selective detection of lectin proteins. The copolymerization of a vinyl linked carbohydrate monomer with acrylamide and acrylic acid forms a carbohydrate hydrogel that shows specific "multivalent" binding to lectin proteins. The resulting carbohydrate hydrogels are attached to 2-D photonic crystals (PCs) that brightly diffract visible light. This diffraction provides an optical readout that sensitively monitors the hydrogel volume. We utilize lactose, galactose, and mannose containing hydrogels to fabricate a series of 2-D PC sensors that show strong selective binding to the lectin proteins ricin, jacalin, and concanavalin A (Con A). This binding causes a carbohydrate hydrogel shrinkage which significantly shifts the diffraction wavelength. The resulting 2-D PC sensors can selectively detect the lectin proteins ricin, jacalin, and Con A. These unoptimized 2-D PC hydrogel sensors show a limit of detection (LoD) of 7.5 × 10-8 M for ricin, a LoD of 2.3 × 10-7 M for jacalin, and a LoD of 3.8 × 10-8 M for Con A, respectively. This sensor fabrication approach may enable numerous sensors for the selective detection of numerous lectin proteins.
Collapse
Affiliation(s)
- Zhongyu Cai
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Aniruddha Sasmal
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Xinyu Liu
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Sanford A. Asher
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| |
Collapse
|
7
|
Brandon DL, McKeon TA, Patfield SA, Kong Q, He X. Analysis of Castor by ELISAs that Distinguish Ricin andRicinus communisagglutinin (RCA). J AM OIL CHEM SOC 2015. [DOI: 10.1007/s11746-015-2773-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- David L. Brandon
- ; Foodborne Toxin Detection and Prevention Research Unit; Western Regional Research Center, USDA Agricultural Research Service; 800 Buchanan Street Albany CA 94710 USA
| | - Thomas A. McKeon
- ; Bioproducts Research Unit; Western Regional Research Center, USDA Agricultural Research Service; 800 Buchanan Street Albany CA 94710 USA
| | - Stephanie A. Patfield
- ; Foodborne Toxin Detection and Prevention Research Unit; Western Regional Research Center, USDA Agricultural Research Service; 800 Buchanan Street Albany CA 94710 USA
| | - Qiulian Kong
- ; Foodborne Toxin Detection and Prevention Research Unit; Western Regional Research Center, USDA Agricultural Research Service; 800 Buchanan Street Albany CA 94710 USA
| | - Xiaohua He
- ; Foodborne Toxin Detection and Prevention Research Unit; Western Regional Research Center, USDA Agricultural Research Service; 800 Buchanan Street Albany CA 94710 USA
| |
Collapse
|
8
|
Worbs S, Skiba M, Söderström M, Rapinoja ML, Zeleny R, Russmann H, Schimmel H, Vanninen P, Fredriksson SÅ, Dorner BG. Characterization of Ricin and R. communis Agglutinin Reference Materials. Toxins (Basel) 2015; 7:4906-34. [PMID: 26703723 PMCID: PMC4690106 DOI: 10.3390/toxins7124856] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 10/07/2015] [Accepted: 10/22/2015] [Indexed: 12/12/2022] Open
Abstract
Ricinus communis intoxications have been known for centuries and were attributed to the toxic protein ricin. Due to its toxicity, availability, ease of preparation, and the lack of medical countermeasures, ricin attracted interest as a potential biological warfare agent. While different technologies for ricin analysis have been established, hardly any universally agreed-upon "gold standards" are available. Expert laboratories currently use differently purified in-house materials, making any comparison of accuracy and sensitivity of different methods nearly impossible. Technically challenging is the discrimination of ricin from R. communis agglutinin (RCA120), a less toxic but highly homologous protein also contained in R. communis. Here, we established both highly pure ricin and RCA120 reference materials which were extensively characterized by gel electrophoresis, liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI MS/MS), and matrix-assisted laser desorption ionization-time of flight approaches as well as immunological and functional techniques. Purity reached >97% for ricin and >99% for RCA120. Different isoforms of ricin and RCA120 were identified unambiguously and distinguished by LC-ESI MS/MS. In terms of function, a real-time cytotoxicity assay showed that ricin is approximately 300-fold more toxic than RCA120. The highly pure ricin and RCA120 reference materials were used to conduct an international proficiency test.
Collapse
Affiliation(s)
- Sylvia Worbs
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| | - Martin Skiba
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| | - Martin Söderström
- VERIFIN (Finnish Institute for Verification of the ChemicalWeapons Convention), Department of Chemistry, University of Helsinki, A.I. Virtasen aukio 1, Helsinki 05600, Finland.
| | - Marja-Leena Rapinoja
- VERIFIN (Finnish Institute for Verification of the ChemicalWeapons Convention), Department of Chemistry, University of Helsinki, A.I. Virtasen aukio 1, Helsinki 05600, Finland.
| | - Reinhard Zeleny
- European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, 2440 Geel, Belgium.
| | - Heiko Russmann
- Bundeswehr Research Institute for Protective Technologies and NBC Protection, Humboldtstr. 100, 29633 Munster, Germany.
| | - Heinz Schimmel
- European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, 2440 Geel, Belgium.
| | - Paula Vanninen
- VERIFIN (Finnish Institute for Verification of the ChemicalWeapons Convention), Department of Chemistry, University of Helsinki, A.I. Virtasen aukio 1, Helsinki 05600, Finland.
| | - Sten-Åke Fredriksson
- FOI, Swedish Defence Research Agency, CBRN Defence and Security, Cementvagen 20, 901 82 Umeå, Sweden.
| | - Brigitte G Dorner
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| |
Collapse
|
9
|
Gaylord ST, Dinh TL, Goldman ER, Anderson GP, Ngan KC, Walt DR. Ultrasensitive Detection of Ricin Toxin in Multiple Sample Matrixes Using Single-Domain Antibodies. Anal Chem 2015; 87:6570-7. [DOI: 10.1021/acs.analchem.5b00322] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shonda T. Gaylord
- Department
of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Trinh L. Dinh
- Department
of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Ellen R. Goldman
- Center for Bio/Molecular
Science and Engineering, Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375, United States
| | - George P. Anderson
- Center for Bio/Molecular
Science and Engineering, Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375, United States
| | - Kevin C. Ngan
- Department
of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - David R. Walt
- Department
of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| |
Collapse
|
10
|
Schieltz DM, McWilliams LG, Kuklenyik Z, Prezioso SM, Carter AJ, Williamson YM, McGrath SC, Morse SA, Barr JR. Quantification of ricin, RCA and comparison of enzymatic activity in 18 Ricinus communis cultivars by isotope dilution mass spectrometry. Toxicon 2015; 95:72-83. [PMID: 25576235 PMCID: PMC5303535 DOI: 10.1016/j.toxicon.2015.01.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 12/20/2014] [Accepted: 01/06/2015] [Indexed: 11/22/2022]
Abstract
The seeds of the Ricinus communis (Castor bean) plant are the source of the economically important commodity castor oil. Castor seeds also contain the proteins ricin and R. communis agglutinin (RCA), two toxic lectins that are hazardous to human health. Radial immunodiffusion (RID) and the enzyme linked immunosorbent assay (ELISA) are two antibody-based methods commonly used to quantify ricin and RCA; however, antibodies currently used in these methods cannot distinguish between ricin and RCA due to the high sequence homology of the respective proteins. In this study, a technique combining antibody-based affinity capture with liquid chromatography and multiple reaction monitoring (MRM) mass spectrometry (MS) was used to quantify the amounts of ricin and RCA independently in extracts prepared from the seeds of eighteen representative cultivars of R. communis which were propagated under identical conditions. Additionally, liquid chromatography and MRM-MS was used to determine rRNA N-glycosidase activity for each cultivar and the overall activity in these cultivars was compared to a purified ricin standard. Of the cultivars studied, the average ricin content was 9.3 mg/g seed, the average RCA content was 9.9 mg/g seed, and the enzymatic activity agreed with the activity of a purified ricin reference within 35% relative activity.
Collapse
Affiliation(s)
- David M Schieltz
- Clinical Chemistry Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway N.E., MS-F50, Atlanta, GA 30341, USA
| | - Lisa G McWilliams
- Clinical Chemistry Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway N.E., MS-F50, Atlanta, GA 30341, USA
| | - Zsuzsanna Kuklenyik
- Clinical Chemistry Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway N.E., MS-F50, Atlanta, GA 30341, USA
| | - Samantha M Prezioso
- Division of Foodborne, Waterborne and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Center for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333, USA
| | - Andrew J Carter
- Division of Foodborne, Waterborne and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Center for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333, USA
| | - Yulanda M Williamson
- Clinical Chemistry Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway N.E., MS-F50, Atlanta, GA 30341, USA
| | - Sara C McGrath
- Clinical Chemistry Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway N.E., MS-F50, Atlanta, GA 30341, USA
| | - Stephen A Morse
- Division of Foodborne, Waterborne and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Center for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333, USA
| | - John R Barr
- Clinical Chemistry Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway N.E., MS-F50, Atlanta, GA 30341, USA.
| |
Collapse
|
11
|
Bozza WP, Tolleson WH, Rivera Rosado LA, Zhang B. Ricin detection: Tracking active toxin. Biotechnol Adv 2015; 33:117-123. [DOI: 10.1016/j.biotechadv.2014.11.012] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 10/22/2014] [Accepted: 11/30/2014] [Indexed: 12/11/2022]
|
12
|
Guo P, Wang J, Dong G, Wei D, Li M, Yang M, Kong L. NMR-based metabolomics approach to study the chronic toxicity of crude ricin from castor bean kernels on rats. MOLECULAR BIOSYSTEMS 2014; 10:2426-40. [PMID: 24992468 DOI: 10.1039/c4mb00251b] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
Ricin, a large, water soluble toxic glycoprotein, is distributed majorly in the kernels of castor beans (the seeds of Ricinus communis L.) and has been used in traditional Chinese medicine (TCM) or other folk remedies throughout the world. The toxicity of crude ricin (CR) from castor bean kernels was investigated for the first time using an NMR-based metabolomic approach complemented with histopathological inspection and clinical chemistry. The chronic administration of CR could cause kidney and lung impairment, spleen and thymus dysfunction and diminished nutrient intake in rats. An orthogonal signal correction partial least-squares discriminant analysis (OSC-PLSDA) of metabolomic profiles of rat biofluids highlighted a number of metabolic disturbances induced by CR. Long-term CR treatment produced perturbations on energy metabolism, nitrogen metabolism, amino acid metabolism and kynurenine pathway, and evoked oxidative stress. These findings could explain well the CR induced nephrotoxicity and pulmonary toxicity, and provided several potential biomarkers for diagnostics of these toxicities. Such a (1)H NMR based metabolomics approach showed its ability to give a systematic and holistic view of the response of an organism to drugs and is suitable for dynamic studies on the toxicological effects of TCM.
Collapse
Affiliation(s)
- Pingping Guo
- State Key Laboratory of Natural Medicines, Department of Natural Medicinal Chemistry, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, PR China.
| | | | | | | | | | | | | |
Collapse
|
13
|
RASOOLY REUVEN, HE XIAOHUA. Sensitive Bioassay for Detection of Biologically Active Ricin in Food. J Food Prot 2012; 75:951-4. [DOI: 10.4315/0362-028x.jfp-11-448] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The potential use of ricin as an agent of biological warfare highlights the need to develop fast and effective methods to detect biologically active ricin. The current “gold standard” for ricin detection is an in vivo mouse bioassay; however, this method is not practical to test on a large number of samples and raises ethical concerns with regard to the use of experimental animals. In this work, we generated adenoviral vectors that express the green fluorescent protein gene and used the relative fluorescence units intensity inhibition by transduced cells for quantitative measurement of biologically active ricin. The detection limit of the assay was 200 pg/ml, which is over 500,000 times greater than the adult human lethal oral dose. The inhibition of fluorescence intensity between ricin treatment and control was higher in 72-h posttransduction Vero cells than 24-h human embryonic kidney cells. Therefore, to detect biologically active ricin in food matrices that might influence the assay, we used 72-h posttransduction Vero cells. This simple assay could be used for large-scale screening to detect biologically active ricin in food without added substrates or use of cell fixation methods.
Collapse
Affiliation(s)
- REUVEN RASOOLY
- U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center, 800 Buchanan Street, Albany, California 94710, USA
| | - XIAOHUA HE
- U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center, 800 Buchanan Street, Albany, California 94710, USA
| |
Collapse
|
14
|
Real-time cytotoxicity assay for rapid and sensitive detection of ricin from complex matrices. PLoS One 2012; 7:e35360. [PMID: 22532852 PMCID: PMC3330811 DOI: 10.1371/journal.pone.0035360] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Accepted: 03/15/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND In the context of a potential bioterrorist attack sensitive and fast detection of functionally active toxins such as ricin from complex matrices is necessary to be able to start timely countermeasures. One of the functional detection methods currently available for ricin is the endpoint cytotoxicity assay, which suffers from a number of technical deficits. METHODOLOGY/FINDINGS This work describes a novel online cytotoxicity assay for the detection of active ricin and Ricinus communis agglutinin, that is based on a real-time cell electronic sensing system and impedance measurement. Characteristic growth parameters of Vero cells were monitored online and used as standardized viability control. Upon incubation with toxin the cell status and the cytotoxic effect were visualized using a characteristic cell index-time profile. For ricin, tested in concentrations of 0.06 ng/mL or above, a concentration-dependent decrease of cell index correlating with cytotoxicity was recorded between 3.5 h and 60 h. For ricin, sensitive detection was determined after 24 h, with an IC50 of 0.4 ng/mL (for agglutinin, an IC50 of 30 ng/mL was observed). Using functionally blocking antibodies, the specificity for ricin and agglutinin was shown. For detection from complex matrices, ricin was spiked into several food matrices, and an IC50 ranging from 5.6 to 200 ng/mL was observed. Additionally, the assay proved to be useful in detecting active ricin in environmental sample materials, as shown for organic fertilizer containing R. communis material. CONCLUSIONS/SIGNIFICANCE The cell-electrode impedance measurement provides a sensitive online detection method for biologically active cytotoxins such as ricin. As the cell status is monitored online, the assay can be standardized more efficiently than previous approaches based on endpoint measurement. More importantly, the real-time cytotoxicity assay provides a fast and easy tool to detect active ricin in complex sample matrices.
Collapse
|
15
|
Worbs S, Köhler K, Pauly D, Avondet MA, Schaer M, Dorner MB, Dorner BG. Ricinus communis intoxications in human and veterinary medicine-a summary of real cases. Toxins (Basel) 2011; 3:1332-72. [PMID: 22069699 PMCID: PMC3210461 DOI: 10.3390/toxins3101332] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 09/26/2011] [Accepted: 09/30/2011] [Indexed: 12/11/2022] Open
Abstract
Accidental and intended Ricinus communis intoxications in humans and animals have been known for centuries but the causative agent remained elusive until 1888 when Stillmark attributed the toxicity to the lectin ricin. Ricinus communis is grown worldwide on an industrial scale for the production of castor oil. As by-product in castor oil production ricin is mass produced above 1 million tons per year. On the basis of its availability, toxicity, ease of preparation and the current lack of medical countermeasures, ricin has gained attention as potential biological warfare agent. The seeds also contain the less toxic, but highly homologous Ricinus communis agglutinin and the alkaloid ricinine, and especially the latter can be used to track intoxications. After oil extraction and detoxification, the defatted press cake is used as organic fertilizer and as low-value feed. In this context there have been sporadic reports from different countries describing animal intoxications after uptake of obviously insufficiently detoxified fertilizer. Observations in Germany over several years, however, have led us to speculate that the detoxification process is not always performed thoroughly and controlled, calling for international regulations which clearly state a ricin threshold in fertilizer. In this review we summarize knowledge on intended and unintended poisoning with ricin or castor seeds both in humans and animals, with a particular emphasis on intoxications due to improperly detoxified castor bean meal and forensic analysis.
Collapse
Affiliation(s)
- Sylvia Worbs
- Centre for Biological Security, Microbial Toxins (ZBS3), Robert Koch-Institut, Nordufer 20, Berlin 13353, Germany; (S.W.); (D.P.); (M.B.D.)
| | - Kernt Köhler
- Institute of Veterinary Pathology, Justus Liebig University Giessen, Frankfurter Street 96, Giessen 35392, Germany;
| | - Diana Pauly
- Centre for Biological Security, Microbial Toxins (ZBS3), Robert Koch-Institut, Nordufer 20, Berlin 13353, Germany; (S.W.); (D.P.); (M.B.D.)
| | - Marc-André Avondet
- Biology and Chemistry Section, Federal Department of Defence, Civil Protection and Sports DDPS SPIEZ LABORATORY, Austrasse 1, Spiez CH-3700, Switzerland; (M.-A.A.); (M.S.)
| | - Martin Schaer
- Biology and Chemistry Section, Federal Department of Defence, Civil Protection and Sports DDPS SPIEZ LABORATORY, Austrasse 1, Spiez CH-3700, Switzerland; (M.-A.A.); (M.S.)
| | - Martin B. Dorner
- Centre for Biological Security, Microbial Toxins (ZBS3), Robert Koch-Institut, Nordufer 20, Berlin 13353, Germany; (S.W.); (D.P.); (M.B.D.)
| | - Brigitte G. Dorner
- Centre for Biological Security, Microbial Toxins (ZBS3), Robert Koch-Institut, Nordufer 20, Berlin 13353, Germany; (S.W.); (D.P.); (M.B.D.)
| |
Collapse
|
16
|
He X, McMahon S, Henderson TD, Griffey SM, Cheng LW. Ricin toxicokinetics and its sensitive detection in mouse sera or feces using immuno-PCR. PLoS One 2010; 5:e12858. [PMID: 20877567 PMCID: PMC2943921 DOI: 10.1371/journal.pone.0012858] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2010] [Accepted: 08/23/2010] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Ricin (also called RCA-II or RCA(60)), one of the most potent toxins and documented bioweapons, is derived from castor beans of Ricinus communis. Several in vitro methods have been designed for ricin detection in complex food matrices in the event of intentional contamination. Recently, a novel Immuno-PCR (IPCR) assay was developed with a limit of detection of 10 fg/ml in a buffer matrix and about 10-1000-fold greater sensitivity than other methods in various food matrices. METHODS AND FINDINGS In order to devise a better diagnostic test for ricin, the IPCR assay was adapted for the detection of ricin in biological samples collected from mice after intoxication. The limit of detection in both mouse sera and feces was as low as 1 pg/ml. Using the mouse intravenous (iv) model for ricin intoxication, a biphasic half-life of ricin, with a rapid t(1/2)α of 4 min and a slower t(1/2)β of 86 min were observed. The molecular biodistribution time for ricin following oral ingestion was estimated using an antibody neutralization assay. Ricin was detected in the blood stream starting at approximately 6-7 h post- oral intoxication. Whole animal histopathological analysis was performed on mice treated orally or systemically with ricin. Severe lesions were observed in the pancreas, spleen and intestinal mesenteric lymph nodes, but no severe pathology in other major organs was observed. CONCLUSIONS The determination of in vivo toxicokinetics and pathological effects of ricin following systemic and oral intoxication provide a better understanding of the etiology of intoxication and will help in the future design of more effective diagnostic and therapeutic methods.
Collapse
Affiliation(s)
- Xiaohua He
- Foodborne Contaminants Research Unit, Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, California, United States of America
| | - Stephanie McMahon
- Foodborne Contaminants Research Unit, Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, California, United States of America
| | - Thomas D. Henderson
- Foodborne Contaminants Research Unit, Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, California, United States of America
| | - Stephen M. Griffey
- Comparative Pathology Lab, School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
| | - Luisa W. Cheng
- Foodborne Contaminants Research Unit, Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, California, United States of America
| |
Collapse
|
17
|
You WK, Kasman I, Hu-Lowe DD, McDonald DM. Ricinus communis agglutinin I leads to rapid down-regulation of VEGFR-2 and endothelial cell apoptosis in tumor blood vessels. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 176:1927-40. [PMID: 20185574 DOI: 10.2353/ajpath.2010.090561] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ricinus communis agglutinin I (RCA I), a galactose-binding lectin from castor beans, binds to endothelial cells at sites of plasma leakage, but little is known about the amount and functional consequences of binding to tumor endothelial cells. We addressed this issue by examining the effects of RCA I on blood vessels of spontaneous pancreatic islet-cell tumors in RIP-Tag2 transgenic mice. After intravenous injection, RCA I bound strongly to tumor vessels but not to normal blood vessels. At 6 minutes, RCA I fluorescence of tumor vessels was largely diffuse, but over the next hour, brightly fluorescent dots appeared as the lectin was internalized by endothelial cells. RCA I injection led to a dose- and time-dependent decrease in vascular endothelial growth factor receptor-2 (VEGFR-2) immunoreactivity in tumor endothelial cells, with 95% loss over 6 hours. By comparison, VEGFR-3, CD31, and CD105 had decreases in the range of 21% to 33%. Loss of VEGFR-2 was followed by increased activated caspase-3 in tumor vessels. Prior inhibition of VEGF signaling by AG-028262 decreased RCA I binding and internalization into tumor vessels. These findings indicate RCA I preferentially binds to and is internalized by tumor endothelial cells, which leads to VEGFR-2 down-regulation, endothelial cell apoptosis, and tumor vessel regression. Together, the results illustrate the selective impact of RCA I on VEGF signaling in tumor blood vessels.
Collapse
Affiliation(s)
- Weon-Kyoo You
- Department of Anatomy, University of California, San Francisco, CA 94143-0452, USA
| | | | | | | |
Collapse
|
18
|
Pauly D, Kirchner S, Stoermann B, Schreiber T, Kaulfuss S, Schade R, Zbinden R, Avondet MA, Dorner MB, Dorner BG. Simultaneous quantification of five bacterial and plant toxins from complex matrices using a multiplexed fluorescent magnetic suspension assay. Analyst 2009; 134:2028-39. [PMID: 19768210 DOI: 10.1039/b911525k] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Proteotoxins such as ricin, abrin, botulinum neurotoxins type A and B (BoNT/A, BoNT/B) and staphylococcal enterotoxin B (SEB) are regarded as potential biological warfare agents which could be used for bioterrorism attacks on the food chain. In this study we used a novel immunisation strategy to generate high-affinity monoclonal and polyclonal antibodies against native ricin, BoNT/A, and BoNT/B. The antibodies were used along with antibodies against SEB and abrin to establish a highly sensitive magnetic and fluorescent multiplex bead array with excellent sensitivities between 2 ng/L and 546 ng/L from a minimal sample volume of 50 microL. The assay was validated using 20 different related analytes and the assay precision was determined. Advancing the existing bead array technology, the novel magnetic and fluorescent microbeads proved amenable to enrichment procedures, by further increasing sensitivity to 0.3-85 ng/L, starting from a sample volume of 500 microL. Furthermore, the method was successfully applied for the simultaneous identification of the target toxins spiked into complex food matrices like milk, baby food and yoghurt. On the basis of our results, the assay appears to be a good tool for large-scale screening of samples from the food supply chain.
Collapse
Affiliation(s)
- Diana Pauly
- Center for Biological Safety, Microbial Toxins (ZBS3), Robert Koch-Institut, Nordufer 20, 13353 Berlin, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Abstract
We report a case of multisystem organ failure after large volume subcutaneous injection of castor oil for cosmetic enhancement. An unlicensed practitioner injected 500 mL of castor oil bilaterally to the hips and buttocks of a 28-year-old male to female transsexual. Immediate local pain and erythema were followed by abdominal and chest pain, emesis, headache, hematuria, jaundice, and tinnitus. She presented to an emergency department 12 hours postinjection. Persistently hemolyzed blood samples complicated preliminary laboratory analysis. She rapidly deteriorated despite treatment and developed fever, tachycardia, hemolysis, thrombocytopenia, hepatitis, respiratory distress, and anuric renal failure. An infectious diseases evaluation was negative. After intensive supportive care, including mechanical ventilation and hemodialysis, she was discharged 11 days later, requiring dialysis for an additional 1.5 months. Castor oil absorption was inferred from recovery of the Ricinus communis biomarker, ricinine, in the patient's urine (41 ng/mL). Clinicians should anticipate multiple complications after unapproved methods of cosmetic enhancement.
Collapse
|
20
|
Yuan Y, Dai X, Wang D, Zeng X. Purification, characterization and cytotoxicity of malanin, a novel plant toxin from the seeds of Malania oleifera. Toxicon 2009; 54:121-7. [PMID: 19341757 DOI: 10.1016/j.toxicon.2009.03.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Revised: 03/19/2009] [Accepted: 03/23/2009] [Indexed: 11/26/2022]
Abstract
Malanin, a novel plant toxin with a molecular weight of 61,875 Da and an isoelectric point of 5.5, was isolated from Malania oleifera seeds by homogenization, ammonium sulfate precipitation and hydrophobic interaction chromatography (HIC). It is a glycoprotein with two chains, chain-A and chain-B, which are crosslinked by one or more disulfide bonds. The N-terminal amino-acid sequences of malanin are DETXTDEEFN (X was commonly C) in chain-B, and DYPKLTFTTS in chain-A. Malanin exhibited highly cytotoxic activities against cancer cell lines (HeLa, PC-12, MCF-7, K562) and non-cancer cell lines (Vero and MDCK), producing IC(50) values of 0.15+/-0.08, 7.71+/-0.24, 11.20+/-0.02, 15.80+/-0.09, 2.79+/-0.05 and 3.92+/-0.01 nM, respectively. It significantly inhibited the growth of HeLa cells through cell-cycle arrest at S phase and induced an apoptotic response. LD(50) values were determined in ICR mice, which were found to be 26.22 microg/kg and 43.11 mg/kg by i.p. and i.g. respectively. Thus, malanin is amongst the most potent toxin of plant origin.
Collapse
Affiliation(s)
- Yan Yuan
- Department of Life Science and Technology, Kunming University, Kunming 650031, China.
| | | | | | | |
Collapse
|
21
|
Brandon DL, Hernlem BJ. Development of monoclonal antibodies specific forRicinusagglutinins. FOOD AGR IMMUNOL 2009. [DOI: 10.1080/09540100802626487] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
22
|
He X, Lu S, Cheng LW, Rasooly R, Carter JM. Effect of food matrices on the biological activity of ricin. J Food Prot 2008; 71:2053-8. [PMID: 18939752 DOI: 10.4315/0362-028x-71.10.2053] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A cell-free translation assay was applied for the quick detection of ricin in food samples. Three economically important foods-ground beef, low-fat milk, and liquid chicken egg--were tested. The results indicated that ground beef had very little matrix effect on the assay, whereas low-fat milk and liquid chicken egg showed clear interference on the protein translation. A simple dilution in phosphate-buffered saline (PBS) effectively eliminated the translational inhibition from these foods. The concentrations inhibiting 50% of luciferase translation derived from the current study were 0.01 nM for the pure ricin A chain, 0.02 nM for pure ricin, and 0.087 nM for crude ricin in PBS. In most cases, the half inhibitory concentration values for ricin in food matrices were significantly lower than for those in PBS buffer, suggesting that some components in these food matrices might potentiate the activity of ricin. Thermal stability tests indicated that the ricin A chain was the least stable among the three forms of ricin in all matrices measured. The thermal stability of pure and crude ricins varied depending on the matrices. The specific activities of ricin in PBS buffer were confirmed by a neutralization test with ricin-specific and nonspecific antibodies. This study demonstrates that the cell-free translation assay is a rapid and sensitive method for detection of biologically active ricin toxin in ground beef, low-fat milk, and liquid chicken egg and that food matrices can greatly affect the thermal stability of ricin.
Collapse
Affiliation(s)
- Xiaohua He
- Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, California 94710, USA.
| | | | | | | | | |
Collapse
|
23
|
El-Nikhely N, Helmy M, Saeed HM, Abou Shama LA, Abd El-Rahman Z. Ricin A Chain from Ricinus sanguineus: DNA Sequence, Structure and Toxicity. Protein J 2007; 26:481-9. [PMID: 17687522 DOI: 10.1007/s10930-007-9088-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The gene coding for the ricin A-chain from Ricinus sanguineus (RsTA) was isolated and sequenced (GB: DQ661048). Comparison of RsTA with the ricin A-chain from Ricinus communis (RTA) revealed the presence of five differences in the gene sequence. At the protein level only two differences were noticed, the replacement of Asn136 by Ser (N136S) and Ile173 by Val (I174 V). From the RsTA structure model (PMDB: PM0074652), the N136S mutation was predicted to have no effect on RsTA structure. The I174V mutation is believed to have no effect on the RsTA structure or on toxicity since this replacement was found in the Ricinus agglutinin's A-chain and the latter has a comparable toxicity to RTA. The Ser221 of the putative lipase active site was found. Toxicity experiments showed that RsTA and RTA have similar toxicities. This finding proves that the N136S and I174 V mutations have no effect on RsTA toxicity.
Collapse
Affiliation(s)
- N El-Nikhely
- Department of Biotechnology, Institute of Graduate Studies and Research, Alexandria University, Alexandria, Egypt
| | | | | | | | | |
Collapse
|
24
|
He X, Brandon DL, Chen GQ, McKeon TA, Carter JM. Detection of castor contamination by real-time polymerase chain reaction. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2007; 55:545-50. [PMID: 17227091 DOI: 10.1021/jf062381r] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Due to the potential for intentional contamination of food with crude preparations containing ricin, a real-time PCR method was developed for the detection of castor plant material in ground beef. One primer pair was identified and confirmed to be castor-specific and efficient for amplification of ricin in DNA extracts from castor or beef matrices. Of three different DNA extraction protocols compared, the hexadecyltrimethylammonium bromide (CTAB) method yielded the highest quality of DNA for QPCR assay. The detection limit for castor contamination in ground beef samples was <0.001% (<10 microg of castor acetone powder per gram of beef, corresponding to 0.5 microg of ricin), indicating excellent sensitivity for the assay, well below the threshold for oral toxicity.
Collapse
Affiliation(s)
- Xiaohua He
- Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, California 94710, USA
| | | | | | | | | |
Collapse
|