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Delta Endotoxin
Delta endotoxins (δ-endotoxins) are pore-forming toxins produced by ''Bacillus thuringiensis'' species of bacteria. They are useful for their insecticidal action and are the primary toxin produced by Bt maize/corn. During spore formation the bacteria produce crystals of such proteins (hence the name Cry toxins) that are also known as parasporal bodies, next to the endospores; as a result some members are known as a parasporin. The Cyt (cytolytic) toxin group is a group of delta-endotoxins different from the Cry group. Mechanism of action When an insect ingests these proteins, they are activated by proteolytic cleavage. The N-terminus is cleaved in all of the proteins and a C-terminal extension is cleaved in some members. Once activated, the endotoxin binds to the gut epithelium and causes cell lysis by the formation of cation-selective channels, which leads to death. For many years there was no clarity as to the relationship between aminopeptidase N and Bt toxins. Althou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cry3Bb1
Delta endotoxins (δ-endotoxins) are pore-forming toxins produced by ''Bacillus thuringiensis'' species of bacteria. They are useful for their insecticidal action and are the primary toxin produced by Bt maize/corn. During spore formation the bacteria produce crystals of such proteins (hence the name Cry toxins) that are also known as parasporal bodies, next to the endospores; as a result some members are known as a parasporin. The Cyt (cytolytic) toxin group is a group of delta-endotoxins different from the Cry group. Mechanism of action When an insect ingests these proteins, they are activated by proteolytic cleavage. The N-terminus is cleaved in all of the proteins and a C-terminal extension is cleaved in some members. Once activated, the endotoxin binds to the gut epithelium and causes cell lysis by the formation of cation-selective channels, which leads to death. For many years there was no clarity as to the relationship between aminopeptidase N and Bt toxins. Althou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |