Abstract: The present invention relates to a new composition of human recombinant antibody fragments in both single chain or Fab format, which is capable of completely neutralizing the venom of the scorpion Centruroides sculpturatus Ewing (C. sculpturatus. In particular the new composition comprises the scFv fragment 10FG2 (SEQ. ID. No: 1), which has broad cross-reactivity against various Mexican scorpion venom toxins, and the scFv fragment LR (SEQ. ID. No: 2), with more limited cross-reactivity. Alternatively, the new composition comprises the Fab 10FG2 fragment (SEQ. ID. No: 3 and SEQ.ID. No:4) and the Fab LR fragment (SEQ. ID. No: 5 and SEQ.ID. No 6). The two antibody fragments recognize independent epitopes, present in the two main toxins of the scorpion C. sculpturatus, so that they do not interfere with each other during their binding to the same, on the contrary the antibody fragments of the present invention complement the neutralizing activity.

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 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.