Abstract: The present invention is directed to recombinant human antibodies specific for Cn2 toxin from C. noxius scorpion venom. The antibodies are able to recognize the toxin and preferably neutralize it as well as the whole venom of C. noxius scorpion. This invention is also directed to a human non-immune phage display library. One clone that specifically binds the Cn2 toxin was affinity matured by directed evolution. Three cycles of maturation were performed and several scFv clones were isolated which specifically recognize toxin Cn2 with increased Kd of 446 fold. All variants were monomeric and only variants 6009F, 6105F and 6103E showed to be capable of neutralizing toxin Cn2 and the whole venom. Variant 6009F recognizes a different epitope than that of BCF2, a murine monoclonal antibody raised against scorpion toxin Cn2 which is also capable of neutralizing both Cn2 toxin and the whole venom when tested in mice, as well as that of commercially available polyclonal antibody fragments antivenom from horse.

Abstract: The invention concerns genes and fusion of genes that code for scorpion toxins and the corresponding polypeptides. The invention also concerns the use of the polypeptides as immunogens for the generation of antibodies that can recognize and neutralize components of scorpion venom as well as for vaccines to prevent envenomation from stings of scorpions of the genus Centruroides, and to immunogenic matrices for the purification of specific immunoglobulins.