Differentiation, Quantification and Identification of Abrin and <i>Abrus precatorius</i> Agglutinin

• Main Authors: Sylvia Worbs, Bettina Kampa, Martin Skiba, Eva-Maria Hansbauer, Daniel Stern, Hervé Volland, François Becher, Stéphanie Simon, Martin B. Dorner, Brigitte G. Dorner
• Format: Article
• Language: English
• Published: MDPI AG 2021-04-01
• Series: Toxins
• Subjects: Abrin; <i>Abrus precatorius</i>; monoclonal antibodies; ELISA; mass spectrometry; lateral flow assay
• Online Access: https://www.mdpi.com/2072-6651/13/4/284

Abrin, the toxic lectin from the rosary pea plant <i>Abrus precatorius,</i> has gained considerable interest in the recent past due to its potential malevolent use. However, reliable and easy-to-use assays for the detection and discrimination of abrin from related plant proteins such as <i>Abrus precatorius</i> agglutinin or the homologous toxin ricin from <i>Ricinus communis</i> are sparse. To address this gap, a panel of highly specific monoclonal antibodies was generated against abrin and the related <i>Abrus precatorius</i> agglutinin. These antibodies were used to establish two sandwich ELISAs to preferentially detect abrin or <i>A. precatorius</i> agglutinin (limit of detection 22 pg/mL for abrin; 35 pg/mL for <i>A. precatorius</i> agglutinin). Furthermore, an abrin-specific lateral flow assay was developed for rapid on-site detection (limit of detection ~1 ng/mL abrin). Assays were validated for complex food, environmental and clinical matrices illustrating broad applicability in different threat scenarios. Additionally, the antibodies turned out to be suitable for immuno-enrichment strategies in combination with mass spectrometry-based approaches for unambiguous identification. Finally, we were able to demonstrate for the first time how the developed assays can be applied to detect, identify and quantify abrin from a clinical sample derived from an attempted suicide case involving <i>A. precatorius</i>.