FN Archimer Export Format PT J TI Insight into Invertebrate Defensin Mechanism of Action OYSTER DEFENSINS INHIBIT PEPTIDOGLYCAN BIOSYNTHESIS BY BINDING TO LIPID II BT AF SCHMITT, Paulina WILMES, Miriam PUGNIERE, Martine AUMELAS, Andre BACHERE, Evelyne SAHL, Hans-Georg SCHNEIDER, Tanja DESTOUMIEUX-GARZON, Delphine AS 1:1,2;2:3;3:7;4:4,5,6;5:1,2;6:3;7:3;8:1,2; FF 1:PDG-DOP-DCM-BOME-LALR;2:;3:;4:;5:PDG-DOP-DCM-BOME;6:;7:;8:; C1 Univ Montpellier 2, CNRS, UMR 5119, Lab Ecosyst Lagunaires, F-34095 Montpellier, France. Univ Montpellier 2, IFREMER, UMR 5119, Lab Ecosyst Lagunaires,IRD, F-34095 Montpellier, France. Univ Bonn, Inst Med Microbiol Immunol & Parasitol, Pharmaceut Microbiol Sect, D-53105 Bonn, Germany. CNRS, UMR 5048, INSERM, U554, F-34090 Montpellier, France. Univ Montpellier 1, Ctr Biochim Struct, F-34090 Montpellier, France. Univ Montpellier 2, Ctr Biochim Struct, F-34090 Montpellier, France. Ctr Etud Agents Pathogenes & Biotechnol Sante, CNRS, UMR 5236, Inst Biol, F-34965 Montpellier, France. C2 UNIV MONTPELLIER, FRANCE IFREMER, FRANCE UNIV BONN, GERMANY CNRS, FRANCE UNIV MONTPELLIER, FRANCE UNIV MONTPELLIER, FRANCE CPBS, FRANCE SI MONTPELLIER PALAVAS SE PDG-DOP-DCM-BOME-LALR PDG-DOP-DCM-BOME IN WOS Ifremer jusqu'en 2018 copubli-france copubli-europe copubli-univ-france IF 5.328 TC 99 UR https://archimer.ifremer.fr/doc/00014/12503/9369.pdf LA English DT Article AB Three oyster defensin variants (Cg-Defh1, Cg-Defh2, and Cg-Defm) were produced as recombinant peptides and characterized in terms of activities and mechanism of action. In agreement with their spectrum of activity almost specifically directed against Gram-positive bacteria, oyster defensins were shown here to be specific inhibitors of a bacterial biosynthesis pathway rather than mere membrane-active agents. Indeed, at lethal concentrations, the three defensins did not compromise Staphylococcus aureus membrane integrity but inhibited the cell wall biosynthesis as indicated by the accumulation of the UDP-N-acetylmuramyl-pentapeptide cell wall precursor. In addition, a combination of antagonization assays, thin layer chromatography, and surface plasmon resonance measurements showed that oyster defensins bind almost irreversibly to the lipid II peptidoglycan precursor, thereby inhibiting the cell wall biosynthesis. To our knowledge, this is the first detailed analysis of the mechanism of action of antibacterial defensins produced by invertebrates. Interestingly, the three defensins, which were chosen as representative of the oyster defensin molecular diversity, bound differentially to lipid II. This correlated with their differential antibacterial activities. From our experimental data and the analysis of oyster defensin sequence diversity, we propose that oyster defensin activity results from selective forces that have conserved residues involved in lipid II binding and diversified residues at the surface of oyster defensins that could improve electrostatic interactions with the bacterial membranes. PY 2010 PD SEP SO Journal Of Biological Chemistry SN 0021-9258 PU Amer Soc Biochemistry Molecular Biology Inc VL 285 IS 38 UT 000281740100021 BP 29208 EP 29216 DI 10.1074/jbc.M110.143388 ID 12503 ER EF