Reflecting recent work in the

Teixobactin is a nonribosomal antibiotic peptide that inhibits the biosynthesis of peptidoglycan and teichoic acid, thereby disrupting cell wall formation. However, teixobactin’s cellular site of action is unknown. This information could prove useful in developing analogs with potent antibacterial activity.

With this in mind, a fluorescent derivative (sulforhodamine) of teixobactin was prepared and shown to be only slightly less active than the parent peptide against a panel of gram-positive bacteria. Treatment of Bacillus subtilis with fluorescent teixobactin revealed septal staining, consistent with the notion that this peptide binds to cell wall precursors. In addition to a greater understanding of teixobactin itself, use of the fluorescent teixobactin may lead to a greater understanding of peptidoglycan and teichoic acid synthesis.