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Updated: Jul 9, 2026

Production and Visualization of Bacterial Spheroplasts and Protoplasts to Characterize Antimicrobial Peptide Localization
Published on: August 11, 2018
Fuscopeptins, antimicrobial lipodepsipeptides from Pseudomonas fuscovaginae, are channel forming peptides active on
M Coraiola1, R Paletti, A Fiore
1FBK & CNR Istituto di Biofisica, via alla Cascata 56/C, I-38100 Povo (Trento), Italy.
Abstract:
FP-A and FP-B are LDPs produced by the plant pathogen Pseudomonas fuscovaginae. As expected from their primary structure, they shared a similar mechanism of action with the better characterized SPs, synthesized by strains of Pseudomonas syringae pv. syringae. Indeed, they displayed hemolytic activity on human erythrocytes and were able to induce calcein release from LUVs: the effect was dependent on the concentration of the FPs and the lipid composition of the liposome and, in particular, it increased with the SM content of the membrane. The permeabilizing activity was further investigated on PLMs. FPs were able to open pores on pure POPC membranes. Pore opening was strongly voltage dependent: by switching the potential from negative to positive values, an increase in the absolute amplitude of transmembrane current was induced with simultaneous closure of pores. In 0.1 M KCl both FPs' pores had a conductance of 4 and 9 pS at - 140 mV and + 140 mV, respectively. Studies on ion selectivity indicated that FPs formed cation-selective channels.
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