Aeromonas piscicola AH‐3 expresses an extracellular collagenase with cytotoxic properties. (29th December 2014)

• Record Type: Journal Article
• Authors: Duarte, A.S.; Cavaleiro, E.; Pereira, C.; Merino, S.; Esteves, A.C.; Duarte, E.P.; Tomás, J.M.; Correia, A.C.
• Is Part Of: Letters in applied microbiology. Volume 60:Number 3(2015:Mar.)
• Page Start: 288
• Page End: 297
• Publication Date: 2014-12-29
• Subjects: Microbiology -- Periodicals; 660.62
• DOI: 10.1111/lam.12373
• Languages: English
• ISSNs: 0266-8254

Abstract

<abstract abstract-type="main" id="lam12373-abs-0001"> <title>Abstract</title> <sec id="lam12373-sec-0501" sec-type="section"> <p>The aim of this study was to investigate the presence and the phenotypic expression of a gene coding for a putative collagenase. This gene (AHA_0517) was identified in <italic>Aeromonas hydrophila </italic>ATCC 7966 genome and named <italic>colAh</italic>. We constructed and characterized an <italic>Aeromonas piscicola </italic>AH‐3::<italic>colAh</italic> knockout mutant. Collagenolytic activity of the wild‐type and mutant strains was determined, demonstrating that <italic>colAh</italic> encodes for a collagenase. ColAh–collagen interaction was assayed by Far‐Western blot, and cytopathic effects were investigated in Vero cells. We demonstrated that ColAh is a gluzincin metallopeptidase (approx. 100 kDa), able to cleave and physically interact with collagen, that contributes for <italic>Aeromonas</italic> collagenolytic activity and cytotoxicity. ColAh possess the consensus HEXXH sequence and a glutamic acid as the third zinc binding positioned downstream the HEXXH motif, but has low sequence similarity and distinct domain architecture to the well‐known clostridial collagenases. In addition, these results highlight the importance of exploring new microbial collagenases that may have significant relevance for the health and biotechnological industries.</p> </sec> <sec id="lam12373-sec-0511" sec-type="section"> <title>Significance and Impact of the Study</title> <p>Collagenases play a central role in processes where collagen digestion is needed, for example host invasion by pathogenic micro‐organisms. We identified a new collagenase from <italic>Aeromonas</italic> using an integrated <italic>in silico</italic>/<italic>in vitro</italic> strategy. This enzyme is able to bind and cleave collagen, contributes for AH‐3 cytotoxicity and shares low similarity with known bacterial collagenases. This is the first report of an enzyme belonging to the gluzincin subfamily of the M9 family of peptidases in <italic>Aeromonas</italic>. This study increases the current knowledge on collagenolytic enzymes bringing new perspectives for biotechnology/medical purposes.</p> </sec> </abstract>