Investigation of the N-Terminus Amino Function of Arg-Teixobactin.

Teixobactin is a recently described antimicrobial peptide that shows high activity against gram-positive bacteria as well as . Due to both its structure as a head-to-side chain cyclodepsipeptide and its activity, it has attracted the attention of several research groups. In this regard, a large number of analogs with substitutions in both the cycle and the tail has been described. Here, we report the contribution of the -terminus residue, -Me-d-Phe, to the activity of Arg-teixobactin. On the basis of our findings, we conclude that the -terminus accepts minimum changes but not the presence of long alkyl chains. The presence of a positive charge is a requirement for the activity of the peptide. Furthermore, acylation of the -terminus leads to total loss of activity.