Process Biotechnology

Marine Biotechnology

Electronic Journal of Biotechnology ISSN: 0717-3458 Vol. 8 No. 3, Issue of December 15, 2005
© 2005 by Pontificia Universidad Católica de Valparaíso -- Chile Received June 16, 2005 / Accepted August 10, 2005
DOI: 10.2225/vol8-issue3-fulltext-2  
RESEARCH ARTICLE

Gill tissues of the mussel Mytilus edulis chilensis: A new source for antimicrobial peptides

Luis Mercado*
Laboratorio de Genética e Inmunología Molecular
Instituto de Biología
Pontificia Universidad Católica de Valparaíso
Av. Brasil 2950, Valparaíso, Chile
Tel: 56 32 273117
Fax: 56 32 596703
E-mail: lmercado@ucv.cl

Paulina Schmitt
Laboratorio de Genética e Inmunología Molecular
Instituto de Biología
Pontificia Universidad Católica de Valparaíso
Av. Brasil 2950, Valparaíso, Chile
Tel: 56 32 273117
Fax: 56 32 596703
E-mail: paulina.schmitt@ucv.cl

Sergio H. Marshall
Laboratorio de Genética e Inmunología Molecular
Instituto de Biología
Pontificia Universidad Católica de Valparaíso
Av. Brasil 2950, Valparaíso, Chile
Tel: 56 32 273117
Fax: 56 32 596703
E-mail: smarshal@ucv.cl

Gloria Arenas
Laboratorio de Genética e Inmunología Molecular
Instituto de Biología
Pontificia Universidad Católica de Valparaíso
Av. Brasil 2950, Valparaíso, Chile
Tel: 56 32 273117
Fax: 56 32 596703
E-mail: garenas@ucv.cl

*Corresponding author


Financial support: INCO-DEV: IMMUNAQUA ICA4-CT-2001-10023 and DI-PUCV 122.779/2004.

Keywords: antimicrobial peptides, gill tissues, mussels.

Abbreviations:  

ACN: acetonitrile
AE: acid extract
AMPs: antimicrobial peptides
BCA: bicinchoninic acid
OD: optical density
SE: Sulfoethyl SE


Abstract
Full Text

Antimicrobial peptides are small-sized, cationic and amphipathic molecules able to neutralize pathogenic microorganisms. Their antimicrobial effects tie them to mechanisms of immune defense, which is why they have been normally purified from immune cells. We describe an apparently new group ofantimicrobial peptides from gill tissues of the mussel Mytilus edulis chilensis. 20 specimens yielded 40 g of gills which produced 16 mg of an enriched fraction with antimicrobial activity as low as 0.045 µg/µl over reference strains. Considering the chemical nature of these molecules we used an acid extraction procedure followed by consecutive cationic exchange and hydrophobic interaction chromatography steps for peptide enrichment. The resulting post Sep-pak C-18® 20% acetonitrile (ACN) eluate was fractionated by reverse phase HPLC and all resulting fractions were the source for in vitro antimicrobial activity evaluation. Active fractions were characterized by SDS-containing protein gel electrophoresis. All fractions were particularly enriched with low molecular weight peptides displaying neutralizing growth activity against Gram positive and Gram negative bacteria and 10 times more efficient over fungal pathogens. Active fractions resulted to be thermostable and non cytotoxic to eukaryotic cells. Considering these results, industrial waste gills of bivalves arise as a new source for antimicrobial molecules.  

 
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