Biotechnologie, Agronomie, Société et Environnement (Jan 2013)
Interactions des antibiotiques ituriniques avec la membrane plasmique. Apport des systèmes biomimétiques des membranes (synthèse bibliographique)
Abstract
Interactions of iturinic antibiotics with plasma membrane. Contribution of biomimetic membranes. Iturinic antibiotics are produced by Bacillus subtilis strains and constitute a family including iturin A, mycosubtilin and bacillomycins D, F and Lc. These are cyclic lipopeptides with β-amino fatty acids linked up to a peptide constituted by seven α-aminoacids with an invariable LDDLLDL chiral sequence. The first three α-aminoacids containing the tyrosyl residue are the same for all members. They are well known for their strong antifungal activities but they also have antibacterial and hemolytic properties. These biological properties are due to their amphiphilic nature, allowing interactions with different membrane components. Sterols found in plasma membranes are the privileged interaction partners of these lipopeptides. Moreover, the tyrosyl residue of the iturinic antibiotics seems to play an important role during their fixation to the plasma membrane, the result of which is often cellular lysis. Within plasma membranes, there are particular regions with a high sterol content. These microdomains have a different composition compared to the rest of the membrane; they are rich in certain lipids and proteins and are involved in many key cellular processes. The perturbation of these microdomains could therefore have an important impact on the cell. Due to their composition, these microdomains may constitute the preferential target of iturin antibiotics. This review aims to summarize the studies relating to the biological activities of iturinic antibiotics. It focuses in particular on the existing knowledge regarding iturin antibiotics at the molecular level and discusses both the key chemical groups of these drugs and the potentiality of microdomains to constitute a target for these molecules.
