The modified Cry1Ca protein is a synthetic protein from the Cry1C group of Bacillus thuringiensis crystal delta-endotoxins. Cry1C proteins belong to the family of three-domain-Cry toxins containing a N-terminal toxic half with three-domain structure (“active toxin”) and a C-terminal half. Domain I is involved in the formation of ion channels that are poorly selective to either cations or anions, depending on pH. The intervening loops linking the β-sheets of domain II and III are involved in very specific interactions with receptors present on the cell membrane of the gut epithelial cells in the insect larvae. The protein has a similar pore forming mode of action to other crystal proteins. Thus, upon ingestion by Lepidopteran larvae, the C-terminal part (roughly 60–70 kDa in Cry1 proteins) of the toxin, together with the first N-terminal 26–29 amino acid residues, are cleaved by trypsin-like gut proteases. The remaining part of the “active toxin” becomes folded, allowing further oligomer formation and interaction with the apical cell membrane of the gut epithelium to form pores. These pores act as non-selective ion channels causing cell swelling, lysis and death. The synthetic protein confers resistance to damage by Lepidopteran insects, such as maruca pod borer (Maruca vitrata).