FN Archimer Export Format PT J TI Alterins Produced by Oyster-Associated Pseudoalteromonas are Antibacterial Cyclolipopeptides with LPS-Binding Activity BT AF Desriac, Florie El Harras, Abderrafek Simon, Matthieu Bondon, Arnaud Brillet, Benjamin Le Chevalier, Patrick Pugnière, Martine Got, Patrice Destoumieux-Garzón, Delphine Fleury, Yannick AS 1:1;2:2;3:2;4:2;5:1;6:1;7:3;8:4;9:5;10:1; FF 1:;2:;3:;4:;5:;6:;7:;8:;9:;10:; C1 Laboratoire de Biotechnologie et Chimie Marine, EA3884, Université de Bretagne Occidentale, Université Bretagne Sud, 29334 Quimper, France Institut des Sciences Chimiques de Rennes-CNRS-UMR 6226, Université Rennes, 35043 Rennes, France IRCM, Institut de Recherche en Cancérologie de Montpellier, INSERM U1194, Université de Montpellier, Institut régional du Cancer de Montpellier, 34298 Montpellier, France MARBEC Université de Montpellier, CNRS, IRD, Place Eugène Bataillon CC 093, Place Eugène Bataillon, CEDEX 5, 34095 Montpellier, France Interactions Hôtes-Pathogènes-Environnements, Université de Montpellier, CNRS, Ifremer, Université Perpignan Via Domitia, 34095 Montpellier, France C2 UBO, FRANCE UNIV RENNES, FRANCE INSERM, FRANCE CNRS, FRANCE CNRS, FRANCE UM MARBEC IHPE IN WOS Cotutelle UMR DOAJ copubli-france copubli-univ-france IF 1.103 TC 13 UR https://archimer.ifremer.fr/doc/00663/77511/79275.pdf LA English DT Article DE ;Pseudoalteromonas;cyclolipopeptides;alterin;antibiotic AB Discovery after discovery, host-associated microbiota reveal a growing list of positive effects on host homeostasis by contributing to host nutrition, improving hosts’ immune systems and protecting hosts against pathogens. In that context, a collection of oyster associated bacteria producing antibacterial compounds have been established to evaluate their role in non-host-derived immunity. Here, we described alterins; potent anti-Gram negative compounds produced by Pseudoalteromonas hCg-6 and hCg-42 isolated from different healthy oyster hemolymph. The strains hCg-6 and hCg-42 produce a set of at least seven antibacterial compounds, ranging from 926 to 982 Da structurally characterized as cyclolipopeptides (CLPs). Alterins share the same cationic heptapeptidic cycle connected via an amido bond to different hydrophobic hydrocarbon tails. Their MICs disclosed a potent antibacterial activity directed against Gram-negative bacteria including oyster and human pathogens that may confer a beneficial defense mechanism to the host but also represents an untapped source of new antibiotics. The alterins’ mechanisms of action have been deciphered: after binding to lipopolysaccharides (LPS), alterins provoke a membrane depolarization and permeabilization leading to bacterial lysis. As hCg-6 and hCg-42 produced a set of natural derivatives, the structure/activity relationship linked to the carbon tail is clarified. We showed that the hydrocarbon tail determines the LPS-binding properties of alterins and consequently their antibacterial activities. Its length and saturation seem to play a major role in this interaction PY 2020 PD DEC SO Marine Drugs SN 1660-3397 PU MDPI AG VL 18 IS 12 UT 000601965900001 DI 10.3390/md18120630 ID 77511 ER EF