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...seffective mechanisms that include the generation of gene-encoded antimicrobial peptidess(AMPs). AMPs are important components of the innate immune system, which have beensconserved during evolution (=-=Brogden, 2005-=-; Yang et al., 2002). They form a key line of hostsdefence against pathogens in plants and animals (Bachère et al., 2004; Boman, 2003; Bulet etsal., 2004). In animals, AMPs are particularly abundant i...

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...espite their great diversity in terms of size, primary structure and amino acidscomposition, most AMPs are characterized by a high content in cationic and hydrophobicsamino acids (Bulet et al., 2004; =-=Jenssen et al., 2006-=-). The resulting amphipathic structure issconsidered to be required for the interaction of the peptide with the membrane of the sensitivesmicroorganisms, leading commonly to the disruption of the memb...

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...t etsal., 2004). In animals, AMPs are particularly abundant in tissues that are likely to come inscontact with microorganisms, such as at mucosal surfaces (Zasloff, 2006a, b) and withinsimmune cells (=-=Bals, 2000-=-; Zhao et al., 2007). AMPs can be classified into three major groups:s(i) linear peptides that can form amphipatic –helices, (ii) peptides containing cysteinesresidues engaged in internal disulphide ...

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...nnate immune system, which have beensconserved during evolution (Brogden, 2005; Yang et al., 2002). They form a key line of hostsdefence against pathogens in plants and animals (Bachère et al., 2004; =-=Boman, 2003-=-; Bulet etsal., 2004). In animals, AMPs are particularly abundant in tissues that are likely to come inscontact with microorganisms, such as at mucosal surfaces (Zasloff, 2006a, b) and withinsimmune c...

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...anisms that include the generation of gene-encoded antimicrobial peptidess(AMPs). AMPs are important components of the innate immune system, which have beensconserved during evolution (Brogden, 2005; =-=Yang et al., 2002-=-). They form a key line of hostsdefence against pathogens in plants and animals (Bachère et al., 2004; Boman, 2003; Bulet etsal., 2004). In animals, AMPs are particularly abundant in tissues that are ...

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...d Hoffmann,s2007). Despite their great diversity in terms of size, primary structure and amino acidscomposition, most AMPs are characterized by a high content in cationic and hydrophobicsamino acids (=-=Bulet et al., 2004-=-; Jenssen et al., 2006). The resulting amphipathic structure issconsidered to be required for the interaction of the peptide with the membrane of the sensitivesmicroorganisms, leading commonly to the ...

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...icrobial activity. Such a synergy with Cg-Def is of particular interest. Indeed, while bothsvertebrate and invertebrate defensins have been shown to play a key role in the defensesagainst infections (=-=Salzman et al., 2003-=-; Tzou et al., 2002), to our knowledge, only defensinssfrom vertebrates have been reported to have synergistic activity with other antimicrobialss(Bals et al., 1998; Levy et al., 1994). Thus, from our...

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... the defensesagainst infections (Salzman et al., 2003; Tzou et al., 2002), to our knowledge, only defensinssfrom vertebrates have been reported to have synergistic activity with other antimicrobialss(=-=Bals et al., 1998-=-; Levy et al., 1994). Thus, from our data, Cg-Prp would be an oyster defensespeptide that acts through synergy with AMPs such as Cg-Def rather than through directskilling of microbes. This is reminisc...

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...antimicrobial compounds have been reported in various tissuessand cell types, as well as specific evidence of synergistic activity (Lauth et al., 2005;sPatrzykat et al., 2001; Rosenfeld et al., 2006; =-=Yan and Hancock, 2001-=-). In conclusion, our results showed that oyster proline-rich peptides and defensins ares(i) present in the same tissues (either hemocytes or mantle through infiltrating hemocytes),sand (ii) display s...

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...h a synergy with Cg-Def is of particular interest. Indeed, while bothsvertebrate and invertebrate defensins have been shown to play a key role in the defensesagainst infections (Salzman et al., 2003; =-=Tzou et al., 2002-=-), to our knowledge, only defensinssfrom vertebrates have been reported to have synergistic activity with other antimicrobialss(Bals et al., 1998; Levy et al., 1994). Thus, from our data, Cg-Prp would...

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...ne in mollusks. To date, mollusks AMPs have been onlysreported in the sea hare Dolabella auricularia (Iijima et al., 2003), the mussels Mytilus edulis (Charlet et al., 1996) and M. galloprovincialis (=-=Hubert et al., 1996-=-), the scallop Argopectensirradians (Zhao et al., 2007), and the oysters C. virginica (Seo et al., 2005) and C. gigas (Gonzalez et al., 2007; Gueguen et al., 2006). All of the AMPs described, which in...

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...nts (putative mature forms) were C-terminally amidatedsassuming Gly elimination, a posttranslational modification frequently observed in AMPss(Destoumieux et al., 1997; Jiravanichpaisal et al., 2007; =-=Mitta et al., 1999-=-). These truncatedsforms were selected as follow: (i) Cg-Prp20-36 because of the presence of a chymotrypsinsensitive site (Phe19), (ii) Cg-Prp22-36 in order to increase peptide cationicity, and (iii) ...

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...heat shock protein involved in chaperone-assisted protein folding. Pyrrhocidin inhibits thesATPase activity of DnaK, which results in the accumulation of misfolded proteins andssubsequent cell death (=-=Kragol et al., 2001-=-). Several proline-rich AMPs have been isolatedsfrom invertebrates (Jiravanichpaisal et al., 2007; Markossian et al., 2004; Rabel et al., 2004;sStensvag et al., 2008), but none in mollusks. To date, m...

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...the peptides reach an intracellular target causing cell deaths(Brogden, 2005). For example, PR39, a mammalian proline-rich AMP kills Gram negativesbacteria by inhibition of DNA and protein synthesis (=-=Gennaro et al., 2002-=-). Similarly, thes4insect pyrrhocidin, drosocin and apidaecin enter the target cells and specifically bind to DnaK,sa heat shock protein involved in chaperone-assisted protein folding. Pyrrhocidin inh...

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...ers(Dynatech).s7Determination of Fractional Inhibitory Concentrations (FICs) - Synergy between C.sgigas antimicrobial peptides was tested using the checkerboard microtiter assay (Rabel et al.,s2004) (=-=Patrzykat et al., 2001-=-). To detect a possible reduction of the MIC values of each peptide when used in combination, 2-fold serial dilutions of one peptide were tested against 2fold serial dilutions of the other peptide. Re...

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...t infections (Salzman et al., 2003; Tzou et al., 2002), to our knowledge, only defensinssfrom vertebrates have been reported to have synergistic activity with other antimicrobialss(Bals et al., 1998; =-=Levy et al., 1994-=-). Thus, from our data, Cg-Prp would be an oyster defensespeptide that acts through synergy with AMPs such as Cg-Def rather than through directskilling of microbes. This is reminiscent of MPAC, the pr...

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...kticus, Vibrio splendidus and V. anguillarum (5 x 108 bacteria/litre) inssea-water tanks. Hemolymph was collected at different times (0, 15, and 72h) in antiaggregant Modified Alsever Solution (MAS) (=-=Bachère et al., 1988-=-). Hemocytes werescollected by centrifugation (700 g, 10 min, 4°C) and fixed in 4% paraformaldehyde forsimmunofluorescence. Oyster tissues were harvested by dissection for in situ hybridization.sPepti...

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...t al., 1996) and M. galloprovincialis (Hubert et al., 1996), the scallop Argopectensirradians (Zhao et al., 2007), and the oysters C. virginica (Seo et al., 2005) and C. gigas (Gonzalez et al., 2007; =-=Gueguen et al., 2006-=-). All of the AMPs described, which includesseveral defensins, belong to the group of cysteine-containing peptides. In this study, we describe the first proline-rich AMP from mollusks. A sequence with...

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...ite), and (iii) an 18-amino acid cationic proline-rich region (pI = 11.83) ending with asGly residue (Fig. 1). The cationic region has significant similarities with AMPs from thesproline-rich family (=-=Otvos, 2002-=-). It also contains two repeats of the Pro-Arg-Pro tripeptide, a motif characteristic of the insect proline-rich AMPs (Otvos, 2002).sThe overall structure of the Cg-Prp precursor suggests that Cg-Prp ...

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...chpaisal et al., 2007; Markossian et al., 2004; Rabel et al., 2004;sStensvag et al., 2008), but none in mollusks. To date, mollusks AMPs have been onlysreported in the sea hare Dolabella auricularia (=-=Iijima et al., 2003-=-), the mussels Mytilus edulis (Charlet et al., 1996) and M. galloprovincialis (Hubert et al., 1996), the scallop Argopectensirradians (Zhao et al., 2007), and the oysters C. virginica (Seo et al., 200...

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...s in vivo. In other species, severalsexamples of co-localization of antimicrobial compounds have been reported in various tissuessand cell types, as well as specific evidence of synergistic activity (=-=Lauth et al., 2005-=-;sPatrzykat et al., 2001; Rosenfeld et al., 2006; Yan and Hancock, 2001). In conclusion, our results showed that oyster proline-rich peptides and defensins ares(i) present in the same tissues (either ...

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...l synthesis of Cg-Prp20-36, Cg-Prp22-36, Cg-Prp26-36 (cationic putative maturespeptides), and Cg-Prp1-19 (anionic putative proregion) was performed on an Abimed AMS 422ssynthesizer by Fmoc chemistry (=-=Gausepohl et al., 1992-=-). Peptides were deprotected andsreleased from the Rink amide resin (Novabiochem) by trifluoroacetic acid treatment in thespresence of appropriate scavengers. Peptides were lyophilized and then purifi...

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...latedsanalogs (Otvos, 2002). Isomerization of the proline peptide bond(s) by a peptidylproline cistrans-isomerase was also reported to be necessary for the activation of a synthetic proline-richsAMP (=-=Luders et al., 2005-=-). The occurrence of such posttranslational modifications in Cg-Prpscould not be evidenced by the molecular biology approach used in this study. Interestingly, three synthetic variants of Cg-Prp displ...

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...ma et al., 2003), the mussels Mytilus edulis (Charlet et al., 1996) and M. galloprovincialis (Hubert et al., 1996), the scallop Argopectensirradians (Zhao et al., 2007), and the oysters C. virginica (=-=Seo et al., 2005-=-) and C. gigas (Gonzalez et al., 2007; Gueguen et al., 2006). All of the AMPs described, which includesseveral defensins, belong to the group of cysteine-containing peptides. In this study, we describ...

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... proteins andssubsequent cell death (Kragol et al., 2001). Several proline-rich AMPs have been isolatedsfrom invertebrates (Jiravanichpaisal et al., 2007; Markossian et al., 2004; Rabel et al., 2004;s=-=Stensvag et al., 2008-=-), but none in mollusks. To date, mollusks AMPs have been onlysreported in the sea hare Dolabella auricularia (Iijima et al., 2003), the mussels Mytilus edulis (Charlet et al., 1996) and M. galloprovi...

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...s of co-localization of antimicrobial compounds have been reported in various tissuessand cell types, as well as specific evidence of synergistic activity (Lauth et al., 2005;sPatrzykat et al., 2001; =-=Rosenfeld et al., 2006-=-; Yan and Hancock, 2001). In conclusion, our results showed that oyster proline-rich peptides and defensins ares(i) present in the same tissues (either hemocytes or mantle through infiltrating hemocyt...

Citation Context

...bel et al., 2004;sStensvag et al., 2008), but none in mollusks. To date, mollusks AMPs have been onlysreported in the sea hare Dolabella auricularia (Iijima et al., 2003), the mussels Mytilus edulis (=-=Charlet et al., 1996-=-) and M. galloprovincialis (Hubert et al., 1996), the scallop Argopectensirradians (Zhao et al., 2007), and the oysters C. virginica (Seo et al., 2005) and C. gigas (Gonzalez et al., 2007; Gueguen et ...

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... thesATPase activity of DnaK, which results in the accumulation of misfolded proteins andssubsequent cell death (Kragol et al., 2001). Several proline-rich AMPs have been isolatedsfrom invertebrates (=-=Jiravanichpaisal et al., 2007-=-; Markossian et al., 2004; Rabel et al., 2004;sStensvag et al., 2008), but none in mollusks. To date, mollusks AMPs have been onlysreported in the sea hare Dolabella auricularia (Iijima et al., 2003),...

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...hich results in the accumulation of misfolded proteins andssubsequent cell death (Kragol et al., 2001). Several proline-rich AMPs have been isolatedsfrom invertebrates (Jiravanichpaisal et al., 2007; =-=Markossian et al., 2004-=-; Rabel et al., 2004;sStensvag et al., 2008), but none in mollusks. To date, mollusks AMPs have been onlysreported in the sea hare Dolabella auricularia (Iijima et al., 2003), the mussels Mytilus edul...

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...ulation of misfolded proteins andssubsequent cell death (Kragol et al., 2001). Several proline-rich AMPs have been isolatedsfrom invertebrates (Jiravanichpaisal et al., 2007; Markossian et al., 2004; =-=Rabel et al., 2004-=-;sStensvag et al., 2008), but none in mollusks. To date, mollusks AMPs have been onlysreported in the sea hare Dolabella auricularia (Iijima et al., 2003), the mussels Mytilus edulis (Charlet et al., ...

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...als (Bachère et al., 2004; Boman, 2003; Bulet etsal., 2004). In animals, AMPs are particularly abundant in tissues that are likely to come inscontact with microorganisms, such as at mucosal surfaces (=-=Zasloff, 2006a-=-, b) and withinsimmune cells (Bals, 2000; Zhao et al., 2007). AMPs can be classified into three major groups:s(i) linear peptides that can form amphipatic –helices, (ii) peptides containing cysteines...