Unlike the CytA toxin from native subsp. (Bti) crystals, the inclusions of cloned CytA produced by Bti IPS 78/11 in the presence of the 20 kDa ‘helper’ protein require a reducing agent in addition to a highly alkaline pH for complete solubilization. Activation of the solubilized CytA with a range of proteases produced 25-22 kDa products. SDS-PAGE analysis and N-terminal amino acid sequencing revealed that CytA was processed very similarly at both termini by proteinase K or by or gut extracts. Trypsin, by contrast, processed CytA predominantly at the N-terminus. cytolytic assays against cells, and haemolytic assays against rat erythrocytes, showed that CytA processed at both termini by proteinase K was the most active form. Thus CytA, like other Bt δ-endotoxins, is processed to a well-defined protease-resistant product and this processing enhances the toxicity and possibly .


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error