Heterologous Expression and Immunogenic Potential of the Most Abundant Phospholipase A(2) from Coral Snake Micrurus dumerilii to Develop Antivenoms

Micrurus dumerilii is a coral snake of clinic interest in Colombia. Its venom is mainly composed of phospholipases A(2) being MdumPLA(2) the most abundant protein. Nevertheless, Micrurus species produce a low quantity of venom, which makes it difficult to produce anticoral antivenoms. Therefore, in this work, we present the recombinant expression of MdumPLA(2) to evaluate its biological activities and its immunogenic potential to produce antivenoms. For this, a genetic construct rMdumPLA(2) was cloned into the pET28a vector and expressed heterologously in bacteria. His-rMdumPLA(2) was extracted from inclusion bodies, refolded in vitro, and isolated using affinity and RP-HPLC chromatography. His-rMdumPLA(2) was shown to have phospholipase A(2) activity, a weak anticoagulant effect, and induced myonecrosis and edema. The anti-His-rMdumPLA(2) antibodies produced in rabbits recognized native PLA(2), the complete venom of M. dumerilii, and a phospholipase from another species of the Micrurus genus. Antibodies neutralized 100% of the in vitro phospholipase activity of the recombinant toxin and a moderate percentage of the myotoxic activity of M. dumerilii venom in mice. These results indicate that His-rMdumPLA(2) could be used as an immunogen to improve anticoral antivenoms development. This work is the first report of an M. dumerilii functional recombinant PLA(2).