Lasso peptides. Bioactive peptides from Actinobacteria and Proteobacteria
Résumé
Certain bacteria produce 16/21-residue peptides that share a compact lasso-folded structure involving a 8/9-residue ring resulting from a lactame bond between the N-terminus and the carboxylic group of an Asp/Glu residue, crossed by the C-terminal tail. These peptides, termed lasso peptides, exhibit a variety of biological activities, involving enzyme inhibition, receptor antagonism or antimicrobial activities. Their compact structure confers to lasso peptide a great resistance to denaturing conditions and certain proteases, which increase their interest as bioactive peptides. The best characterized lasso peptide in terms of structure, mechanism of action and biosynthesis pathway is microcin J25 (MccJ25), a gene-encoded antibacterial peptide secreted by Escherichia coli AY25.