The terminal structure plays an important role in the biological activity of cecropin CMIV

Abstract

Antibacterial peptides have received increasing attention as a new pharmaceutical substance. But the molecular mechanism of lysis is still poorly understood. CMIV gene and mutant CMIV gene in GST fusion system were expressed. After cleaving with different cleavage reagents, the peptide with an excess of N-terminus and with an un-amidated C-terminus stopped the activity while the peptide with an excess Asn at the C-terminus had the activity level the same as natural CMIV. The results showed that the terminal structure of cecropin CMIV played an important role in its biological activity.

High-level Expression of Cecropin X in Escherichia coli

“…Considering the importance of the amidated C-terminus for the antibacterial activity and the lack of amidation in E. coli [ 6 , 7 ], the cDNA encoding cecropin X - a mutant CMIV, with an asparigine residue located at the C-terminus of the peptide, was synthesized in our laboratory [ 8 ]. Then, two methods were described for the production of cecropin X.…”