Abstract
Screening method for determining plant proteinous toxin ricin was developed using polyacrylamide gel electrophoresis (PAGE) and matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS), which are based on the estimation of molecular weight of proteins. From authentic ricin, two protein bands with about 60 kDa were observed by non-reduced sodium dodecyl sulfate (SDS)-PAGE and microchip electrophoretic protein analysis using Agilent 2100 BioAnalyzer. From reduced authentic ricin, several protein bands with about 30 kDa, which are derived from ricin A-chain (RTA) and B-chain (RTB), were observed. Two distinct peaks, which are derived from singly (m/z 62,592) and doubly (m/z 31,401) protonated molecular ions, were detected on the mass spectrum of authentic ricin by MALDI-TOF-MS. Two partly-overlapped peaks around m/z 31,000-32,000, which are derived from singly protonated molecular ions of RTA and RTB, were observed for reduced authentic ricin. It was concluded that the developed analytical methods based on the estimation of molecular weights with and without reduction are useful for screening of ricin.
