Lluis Moll1, Àngel Oliveras1, Lidia Feliu1, Marta Planas1, Esther Badosa2, Emilio Montesinos2
1 LIPPSO, Department of Chemistry, University of Girona, Girona, 17003, Spain; 2 Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Girona, 17003, Spain
Correspondence: Lluis Moll (lluismds@hotmail.com); Lidia Feliu (lidia.feliu@udg.edu)
Nowadays, world population has reached 7,6 billion and it is expected to rise up to 11,2 billion in 2100. This increase requires to step up the agricultural yield in order to supply food for the whole population. A way to achieve this purpose would be reducing the losses caused by microorganisms [1]. Recent restrictions imposed by the European Union on the use of several compounds to combat these pathogens, has prompted the search for safer alternatives. Antimicrobial peptides are considered as optimal candidates.
Some years ago, our group, in collaboration with the Laboratory of Plant Pathology, described the lead peptide KKLFKKILKYL-NH2 (BP100) with antimicrobial activity against economically important plant pathogens [2]. More recently, with the aim of obtaining peptides with better biological properties, several lipopeptides have been synthetized. This type of peptides contains a fatty acid in their structure to favour their insertion into the pathogen membrane [3]. The lipopeptides derived from BP100 displayed high antimicrobial activity, but they were hemolytic and poorly stable.
In this work, in order to enhance the properties of the above BP100 derivatives, new lipopeptides have been described. In particular, the amino acid at position 4 has been replaced by its D enantiomer. This approach has been designed to reduce the hemolysis and to increase the stability, while maintaining the antimicrobial activity [4]. These new lipopeptides have been prepared on solid phase. They have been analysed by HPLC and characterized by ESI-MS. They have been tested against the phytopathogenic bacteria Erwinia amylovora, Pseudomonas syringae pv. syringae, Pseudomonas syringae pv. actinidiae, Xanthomonas arboricola pv. pruni, Xanthomonas fragariae, Xantomonas axonopodis pv. vesicatoria, and the fungi Penicillium expansum and Fusarium oxysporum. Furthermore, the toxicity and the stability have been analysed. The best lipopeptides will be selected to be assayed in vivo and, if they are successful, they will be produced in plants to decrease the production cost.
References
1. Savary S, Ficke A, Aubertot J N, Hollier C. Crop Losses Due to Diseases and Their Implications for Global Food Production Losses and Food Security. Food Secur. 2012; 4:519-537
2. Badosa E, Ferre R, Planas M, Feliu L, Besalú E, Cabrefiga J, Bardají E, Montesinos E. A Library of Linear Undecapeptides with Bactericidal Activity against Phytopathogenic Bacteria. Peptides. 2007; 28:2276-2285.
3. Malina A, Shai Y. Conjugation of Fatty Acids with Different Lenghts Modulates the Antibacterial and Antifungal Activity of Cationic Biologically Inactive Peptide. Biochem J. 2005; 390:695-702.
4. Guell I, Cabrefiga J, Badosa E, Ferre R, Talleda M, Bardají E, Planas M, Feliu L, Montesinos E. Improvement of the Efficacy of Linear Undecapeptides against Plant-Pathogenic Bacteria by Incorporation of D-Amino Acids. Appl Enviorn Mirobiol. 2011; 77:2667-2675.
Funding:
MINECO, Grant AGL2015-69876-C2-2-R; University of Girona, MPCUdG2016/038