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Communication Dans Un Congrès Année : 2005

Siderophore-peptide, a new type of antimicrobial peptide targetting iron-siderophore receptors at the outer membrane of Escherichia coli

Résumé

Microcins are gene-encoded antibacterial peptides secreted by enterobacteria, which act against Gram-negative bacteria and are strongly involved in microbial competitions within the intestinal tract. We have recently isolated a post-translationally modified form of the 84-residue microcin E492 (mccE92m), which exhibits minimal inhibitory concentrations in the nanomolar range. The MccE492m post-translational modification was characterized by biochemical and spectroscopic methods as a trimer of N-(2,3-dihydroxybenzoyl)-L-serine (DHBS) linked via a C-glycosidic linkage to a beta-D-glucose moiety, itself linked to the Ser-84-carboxyl through an O-glycosidic bond. DHBS is a catechol-type siderophore involved in iron uptake by enterobacteria. MccE492m, which bears a siderophore-like post-translational modification, is the first example of a novel type of antibacterial peptide called siderophore-peptide. The MccE492m and MccE492 activity and mechanism of action were studied.We showed that recognition of MccE492m is mediated by iron-siderophore receptors at the surface of bacteria. Moreover, the unmodified form is also recognized by the same receptors. Thus, we propose that MccE492 and MccE492m parasitize iron-siderophore receptors to enter more efficiently into the bacteria and that improvement of MccE492 antimicrobial activity upon modification results from an increase in the microcin/receptor affinity.
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Dates et versions

hal-00147062 , version 1 (15-05-2007)

Identifiants

  • HAL Id : hal-00147062 , version 1

Citer

S. Rebuffat, J. Peduzzi, X. Thomas, D. Destoumieux-Garzón, C. Goulard, et al.. Siderophore-peptide, a new type of antimicrobial peptide targetting iron-siderophore receptors at the outer membrane of Escherichia coli. 1st International Symposium on Biomolecules and Related Compounds, Mar 2005, Montpellier, France. ⟨hal-00147062⟩
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