Attività antibatterica di peptidi estratti da celomociti di echinodermi

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Abstract

[automatically translated] Echinoderms the body's defense against microbial invasion is via cellular mechanisms of innate immunity and humoral. A key component of the humoral factors consists of the antimicrobial peptides (AMPs) preserved by a very broad spectrum of antimicrobial activity against bacteria, viruses and fungi. AMPs are usually consisting of less than 100 amino acids, are cationic and form amphipathic structures. Here we show that the celomociti dell'Echinoideo Paracentrotus lividus and dell'Oloturoideo Holothuria tubulosa contain substances with antimicrobial activity against several human pathogenic bacteria. In both species, in the acid precipitate of the supernatant of the lysate of celomociti is a peptide fraction with low molecular weight (Low Molecular Peptides. LMP) with a mass of between 3 and 5 kDa showing antibacterial activity, assessed as the minimum inhibitory concentration (MIC). In particular, in P. lividus the peptide fraction with less than 5 kDa molecular mass was evaluated against a set of reference bacteria, Gram-positive and Gram-negative bacteria and against human pathogenic fungi: Staphylococcus. aureus ATCC 29213, ATCC 25923, ATCC 43866, Staphylococcus. epidermis DSM 3269, 1457, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 9027, ATCC 10231 Candida albicans and Candida tropicalis ATCC 13803. The 5-CC is active against all microbial strains tested in vitro, with MIC values ranging from 15.8 mg ml -1 and 253.7 mg ml-1. Moreover, in this case Paracentrotus lividus, were characterized AMPs present in the peptide fraction, through the use of a RP-HPLC / Nesi-MSMS. The results have identified three main peptides (Paracentrina I, II, III) with a molecular size of respectively 1251.7, 2088.1 and 2292.2 d. The MSMS analysis showed that peptides respectively include the peptide sequences 9-19, 12-31 and 24-41 of the β-thymosin of P. lividus (AN AJ439718). The β-thymosin is one of the antibacterial peptides present in invertebrates. In H. tubulosa acid precipitated by the supernatant of the lysate of celomociti was isolated a fraction of 3 kDa which showed activity against several bacterial strains: Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus with MIC values ranging from 16.5 micrograms ml-1 and 22.5 micrograms ml-1. Also in both species, the LMPs are capable of inhibiting the activity of staphylococcal biofilms, as demonstrated by the observations fluorescence and confocal microscopy. Further studies are needed to better characterize these antimicrobial components, both from a biochemical point of view that molecular, both to assess the cellular localization and tissue and the modulation of gene expression in the presence of microorganisms. In conclusion celomociti echinoderms can be an important source of antimicrobial agents useful for the development of new strategies for the treatment of biofilms. both to assess the cellular localization and tissue and the modulation of gene expression in the presence of microorganisms. In conclusion celomociti echinoderms can be an important source of antimicrobial agents useful for the development of new strategies for the treatment of biofilms. both to assess the cellular localization and tissue and the modulation of gene expression in the presence of microorganisms. In conclusion celomociti echinoderms can be an important source of antimicrobial agents useful for the development of new strategies for the treatment of biofilms.
Original languageItalian
Pages65-66
Number of pages2
Publication statusPublished - 2010

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