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

Abstract

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 of antimicrobial 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 Seppak 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

Immune mediators of sea-cucumber Holothuria tubulosa (Echinodermata) as source of novel antimicrobial and anti-staphylococcal biofilm agents

“…Acid-soluble protein extracts were prepared according to a previously described method (Mercado et al 2005) with some slight modifications. Coelomocytes (1 × 10 7 ) were suspended in a solution of 10% acetic acid in ISO without EDTA, sonicated (Sonifier Branson, model B-15 Danbury, CT USA) for 1 min at 0°C (1 pulse per second, 70% duty cycle) and centrifuged at 27,000 × g for 30 min at 4°C to remove any precipitate.…”

Design and expression of a retro doublet of cecropin with enhanced activity

“…However, up to now the classical way to have access to these molecules has been their isolation from host organisms, which requires large amount of material with very low yields of functional peptides (Mercado et al 2005). Other alternatives explored have been their chemical synthesis (Andreu et al 1983) or their expression in heterologous systems following their cloning from origins (Piers et al 1993;Zhang et al 1998).…”

Antimicrobial Peptides: Diversity and Perspectives for Their Biomedical Application

“…The continuous discovery of new AMPs groups in diverse organisms has turned these natural antibiotics into the basic elements of a new generation of potential biomedical treatments against infectious diseases in humans and animals. Besides the above, the broad spectrum of biological activities reported for these molecules suggests a potential benefit in cancer treatment, viral and parasitic infections and in the modulation of the immune system, which reinforces the importance of studying these molecules (Mercado et al, 2005;Schweizer, 2009). …”