title: Quantification of ricin, RCA and comparison of enzymatic activity in 18 Ricinus communis cultivars by isotope dilution mass spectrometry.
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.
authors.affiliation: 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.
authors.forename: David M
authors.initials: DM
authors.lastname: Schieltz
authors.affiliation: 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.
authors.forename: Lisa G
authors.initials: LG
authors.lastname: McWilliams
authors.affiliation: 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.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Kuklenyik
authors.affiliation: 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.
authors.forename: Samantha M
authors.initials: SM
authors.lastname: Prezioso
authors.affiliation: 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.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Carter
authors.affiliation: 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.
authors.forename: Yulanda M
authors.initials: YM
authors.lastname: Williamson
authors.affiliation: 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.
authors.forename: Sara C
authors.initials: SC
authors.lastname: McGrath
authors.affiliation: 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.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Morse
authors.affiliation: 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. Electronic address: jbarr@cdc.gov.
authors.forename: John R
authors.initials: JR
authors.lastname: Barr
mesh_terms: D002367:Ricinus communis / Q000737:chemistry* / Q000201:enzymology*; D002853:Chromatography, Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D006026:Glycoside Hydrolases / Q000378:metabolism; D007118:Immunoassay; D010936:Plant Extracts / Q000737:chemistry; D037121:Plant Lectins / Q000737:chemistry*; D012276:Ricin / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry; D053719:Tandem Mass Spectrometry
chemical_list: D010936:Plant Extracts; D037121:Plant Lectins; C017707:Ricinus communis agglutinin-1; D012276:Ricin; D006026:Glycoside Hydrolases
keywords: Cultivar; Mass spectrometry; Quantification; RCA; Ricin; Ricinus communis