Extended Data Fig. 2: LAR does not affect the bacterial cell envelope.
From: A broad-spectrum lasso peptide antibiotic targeting the bacterial ribosome
(a) Inner membrane permeabilization assay in E. coli TOP10 cells with pUC19 plasmid (containing the lacZ gene) using membrane-impermeable dye Ortho-nitrophenyl-β-D-galactopyranoside (ONPG). LAR (40 μg/ml) did not facilitate the uptake of ONPG, unlike colistin (5 μg/ml), which creates membrane pores. Data are representative of two independent experiments. (b) Membrane depolarization assay using DiOC2(3) dye. The fluorescence of the dye quenches when it enters depolarized cells (due to membrane potential disruption). LAR was used at 10xMIC (40 μg/ml). Protonophore, CCCP (20 μM) served as a positive control. Data represent three biological experiments, with error bars indicating SD of three replicates (c) Scanning electron microscopy images of E. coli treated with 10xMIC of LAR, showing no obvious changes in morphology or defects in the cell envelope. The images are representative of two independent samples.
