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Petit, Vanessa W.; Rolland, Jean-luc; Blond, Alain; Cazevieille, Chantal; Djediat, Chakib; Peduzzi, Jean; Goulard, Christophe; Bachere, Evelyne; Dupont, Joelle; Destoumieux-garzon, Delphine; Rebuffat, Sylvie. |
Background. Hemocyanins are respiratory proteins with multiple functions. In diverse crustaceans hemocyanins can release histidine-rich antimicrobial peptides in response to microbial challenge. In penaeid shrimp, strictly antifungal peptides are released from the C-terminus of hemocyanins. Methods. The three-dimensional structure of the antifungal peptide PvHCt from Litopenaeus vannamei was determined by NMR. Its mechanism of action against the shrimp pathogen Fusarium oxysporum was investigated using immunochemistry, fluorescence and transmission electron microscopy. Results. PvHCt folded into an amphipathic α-helix in membrane-mimicking media and displayed a random conformation in aqueous environment. In contact with F. oxysporum, PvHCt bound... |
Tipo: Text |
Palavras-chave: Antimicrobial peptide; Amphipathic helix; Fungi; Membrane bilayer; Nuclear magnetic resonance (NMR); Fluorescence microscopy. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00301/41202/40362.pdf |
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Vassiliadis, Gaelle; Destoumieux-garzon, Delphine; Peduzzi, Jean. |
Class II microcins are 4.9- to 8.9-kDa polypeptides produced by and active against enterobacteria. They are classified into two subfamilies according to their structure and their gene cluster arrangement. While class ha microcins undergo no posttranslational modification, class Jib rnicrocins show a conserved C-terminal sequence that carries a salmochelin-like siderophore motif as a posttranslational modification. Aside from this C-terminal end, which is the signature of class IIb microcins, some sequence similarities can be observed within and between class II subclasses, suggesting the existence of common ancestors. Their mechanisms of action are still under investigation, but several class II microcins use inner membrane proteins as cellular targets,... |
Tipo: Text |
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Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00073/18386/16447.pdf |
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Longeon, Arlette; Peduzzi, Jean; Barthelemy, Michel; Corre, Sophie; Nicolas, Jean-louis; Guyot, Museum National D'Histoire Naturelle. |
A marine bacterium, X 153, was isolated from a pebble collected at St. Anne du Portzic (France). By 16S ribosomal DNA gene sequence analysis, X153 strain was identified as a Pseudoalteromonas sp. close to P. piscicida. The crude culture of X153 was highly active against human pathogenic strains involved in dermatologic diseases, and marine bacteria including various ichthyopathogenic Vibrio strains. The active substance occurred both in bacterial cells and in culture supernatant. An antimicrobial protein was purified to homogeneity by a 4-step procedure using size-exclusion and ion-exchange chromatography. The highly purified P-153 protein is anionic, and sodium dodecylsulfate polyacrylamide gel electrophoresis gives all apparent molecular mass of 87 kDa.... |
Tipo: Text |
Palavras-chave: Probiotic bacteria; Pseudoalteromonas; Antimicrobial protein. |
Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-426.pdf |
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