title: Recommended Mass Spectrometry-Based Strategies to Identify Ricin-Containing Samples.
abstract: Ricin is a protein toxin produced by the castor bean plant (Ricinus communis) together with a related protein known as R. communis agglutinin (RCA120). Mass spectrometric (MS) assays have the capacity to unambiguously identify ricin and to detect ricin's activity in samples with complex matrices. These qualitative and quantitative assays enable detection and differentiation of ricin from the less toxic RCA120 through determination of the amino acid sequence of the protein in question, and active ricin can be monitored by MS as the release of adenine from the depurination of a nucleic acid substrate. In this work, we describe the application of MS-based methods to detect, differentiate and quantify ricin and RCA120 in nine blinded samples supplied as part of the EQuATox proficiency test. Overall, MS-based assays successfully identified all samples containing ricin or RCA120 with the exception of the sample spiked with the lowest concentration (0.414 ng/mL). In fact, mass spectrometry was the most successful method for differentiation of ricin and RCA120 based on amino acid determination. Mass spectrometric methods were also successful at ranking the functional activities of the samples, successfully yielding semi-quantitative results. These results indicate that MS-based assays are excellent techniques to detect, differentiate, and quantify ricin and RCA120 in complex matrices.
authors.affiliation: Centers for Disease Control and Prevention, 4770 Buford Hwy NE, Atlanta, GA 30341, USA. skalb@cdc.gov.
authors.forename: Suzanne R
authors.initials: SR
authors.lastname: Kalb
authors.affiliation: Centers for Disease Control and Prevention, 4770 Buford Hwy NE, Atlanta, GA 30341, USA. dschieltz@cdc.gov.
authors.forename: David M
authors.initials: DM
authors.lastname: Schieltz
authors.affiliation: Service de Pharmacologie et d'Immunoanalyse, Institut de Biologie et de Technologies de Saclay (iBiTec-S), Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA), 91191 Gif-sur-Yvette, France. francois.becher@cea.fr.
authors.forename: François
authors.initials: F
authors.lastname: Becher
authors.affiliation: The Swedish Defence Research Agency (FOI), SE-901 82 Umeå, Sweden. crister.astot@foi.se.
authors.forename: Crister
authors.initials: C
authors.lastname: Astot
authors.affiliation: The Swedish Defence Research Agency (FOI), SE-901 82 Umeå, Sweden. sten-ake.fredriksson@foi.se.
authors.forename: Sten-Åke
authors.initials: SÅ
authors.lastname: Fredriksson
authors.affiliation: Centers for Disease Control and Prevention, 4770 Buford Hwy NE, Atlanta, GA 30341, USA. jbarr@cdc.gov.
authors.forename: John R
authors.initials: JR
authors.lastname: Barr
mesh_terms: D000225:Adenine / Q000737:chemistry; D000595:Amino Acid Sequence; D013058:Mass Spectrometry / Q000379:methods; D037121:Plant Lectins / Q000032:analysis / Q000737:chemistry; D012276:Ricin / Q000032:analysis* / Q000737:chemistry
chemical_list: D037121:Plant Lectins; C017707:Ricinus communis agglutinin-1; D012276:Ricin; D000225:Adenine
keywords: RCA120; Ricinus communis; mass spectrometry; ricin