Analysis of active ricin and castor bean proteins in a ricin preparation, castor bean extract, and surface swabs from a public health investigation

• Published in: Forensic science international 2011-06, Vol.209 (1), p.70-79
• Main Authors: Schieltz, David M, McGrath, Sara C, McWilliams, Lisa G, Rees, Jon, Bowen, Michael D, Kools, John J, Dauphin, Leslie A, Gomez-Saladin, Eduardo, Newton, Bruce N, Stang, Heather L, Vick, Michael J, Thomas, Jerry, Pirkle, James L, Barr, John R
• Format: Article
• Language: English
• Subjects: Assaying; Beans; Biological; Biological and medical sciences; Chemical Warfare Agents - analysis; Database search; Deoxyribonucleic acid; Disease control; DNA; DNA Primers; DNA Probes; Enzymes; Forensic medicine; Forensic sciences; General aspects; Humans; Investigative techniques, diagnostic techniques (general aspects); Mass Spectrometry; Medical sciences; Pathology; Plant Extracts - chemistry; Plant Extracts - genetics; Plant Lectins - genetics; Plant Proteins - isolation & purification; Polymerase Chain Reaction; Proteins; Proteomic analysis; Proteomics; Public Health; Public health. Hygiene; Public health. Hygiene-occupational medicine; RCA120; Ricin; Ricin - analysis; Ricin - genetics; Ricinus communis - chemistry; Ricinus communis - genetics; Spectroscopy; Toxins
• ISSN: 0379-0738; 1872-6283
• DOI: 10.1016/j.forsciint.2010.12.013

Abstract In late February 2008, law enforcement officials in Las Vegas, Nevada, discovered in a hotel room, a copy of The Anarchist Cookbook , suspected castor beans and a “white powder” thought to be a preparation of ricin. Ricin is a deadly toxin from the seed of the castor bean plant ( Ricinus communis ). The United States regulates the possession, use, and transfer of ricin and it is the only substance considered a warfare agent in both the Chemical and the Biological Weapons Conventions. Six samples obtained from the hotel room were analyzed by laboratories at the Centers for Disease Control and Prevention using a panel of biological and mass spectrometric assays. The biological assays (real time-PCR, time resolved fluorescence and cytotoxicity) provided presumptive evidence of active ricin in each of the samples. This initial screen was followed by an in-depth analysis using a novel, state-of-the-art mass spectrometry-based ricin functional assay and high sensitivity tandem mass spectrometry for protein identification. Mass spectrometric analysis positively identified ricin and confirmed that in each of the samples it was enzymatically active. The tandem mass spectrometry analysis used here is the most selective method available to detect ricin toxin. In each sample, ricin was unequivocally identified along with other R. communis plant proteins, including the highly homologous protein RCA120. Although database searches using tandem mass spectra acquired from the samples indicated that additional controlled substances were not present in these samples, the mass spectrometric results did provide extensive detail about the sample contents. To the best of our knowledge following a review of the available literature, this report describes the most detailed analysis of a white powder for a public health or forensic investigation involving ricin.