In vivo selection of Cry1Aa13 toxin mutants with high affinity for intestinal proteinsof the Mediterranean fruit fly Ceratitis capitata from a phage display library

Abstract: In this work we aim to test the hypothesis that in vitro evolution of Cry toxins andtheir selection using phage display technology can be a useful strategy for developing novelinsecticides actives against non-target insects. It was demonstrated that it is possible to select Crytoxin mutants that bind with high affinity to the intestinal proteins of Ceratitis capitata, from alibrary of bacteriophages expressing Cry1Aa13 toxin mutants on their surface. Selected mutantsshowed a completely different amino acid sequence in the loop2 of the domain II compared withthe lepidopteran active wild type protein. These toxins could potentially be active against this nonnaturally target insect, as binding to epithelial cells proteins is the first step required for Cry toxinactivity.