Enhanced detection of abrin: Unraveling AP lyase activity and pioneering innovative assays for advanced biosecurity applications

Abstract

Abrin, a potent ribosome-inactivating protein, is a serious threat as a biological warfare agent. Developing rapid and accurate assays for detecting abrin are crucial for early prevention of related attacks. In this study, we systematically demonstrate that abrin exhibits apurinic/apyrimidinic (AP) lyase activity, with optimal enzymatic function at 63 °C and pH 4.4. Based on this discovery, we create a fluorescence signaling assay (FSA) for swift detecting abrin and further integrate it with a lateral flow assay (LFA), resulting in a novel, portable detection platform (FSA-LFA). This combined assay allows for sensitive detection of abrin at the picogram level, surpassing the limitations of traditional N-glycosidase-based assays. The FSA-LFA platform is cost-effective, highly sensitive, and amenable to field use. Furthermore, it can be readily adapted for the detection of other ribosome-inactivating proteins, offering broad potential for rapid identification of biosecurity threats.