Tryptophan-Containing Cyclic Decapeptides with Activity against Plant Pathogenic Bacteria
Cristina Camó,
Maria Torné,
Emili Besalú,
Cristina Rosés,
Anna D. Cirac,
Gemma Moiset,
Esther Badosa,
Eduard Bardají,
Emilio Montesinos,
Marta Planas,
Lidia Feliu
Affiliations
Cristina Camó
LIPPSO, Departament de Química, University of Girona, Maria Aurèlia Capmany 69, 17003 Girona, Spain
Maria Torné
LIPPSO, Departament de Química, University of Girona, Maria Aurèlia Capmany 69, 17003 Girona, Spain
Emili Besalú
Institut de Química Computacional i Catàlisi i Departament de Química, University of Girona, Maria Aurèlia Capmany 69, 17003 Girona, Spain
Cristina Rosés
LIPPSO, Departament de Química, University of Girona, Maria Aurèlia Capmany 69, 17003 Girona, Spain
Anna D. Cirac
LIPPSO, Departament de Química, University of Girona, Maria Aurèlia Capmany 69, 17003 Girona, Spain
Gemma Moiset
LIPPSO, Departament de Química, University of Girona, Maria Aurèlia Capmany 69, 17003 Girona, Spain
Esther Badosa
Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Maria Aurèlia Capmany 61, 17003 Girona, Spain
Eduard Bardají
LIPPSO, Departament de Química, University of Girona, Maria Aurèlia Capmany 69, 17003 Girona, Spain
Emilio Montesinos
Laboratory of Plant Pathology, Institute of Food and Agricultural Technology-CIDSAV-XaRTA, University of Girona, Maria Aurèlia Capmany 61, 17003 Girona, Spain
Marta Planas
LIPPSO, Departament de Química, University of Girona, Maria Aurèlia Capmany 69, 17003 Girona, Spain
Lidia Feliu
LIPPSO, Departament de Química, University of Girona, Maria Aurèlia Capmany 69, 17003 Girona, Spain
A library of 66 cyclic decapeptides incorporating a Trp residue was synthesized on solid phase and screened against the phytopathogenic bacteria Pseudomonas syringae pv. syringae, Xanthomonas axonopodis pv. vesicatoria, and Erwinia amylovora. The hemolytic activity of these peptides was also evaluated. The results obtained were compared with those of a collection of Phe analogues previously reported. The analysis of the data showed that the presence of the Trp improved the antibacterial activity against these three pathogens. In particular, 40 to 46 Trp analogues displayed lower minimum inhibitory concentration (MIC) values than their corresponding Phe counterparts. Interestingly, 26 Trp-containing sequences exhibited MIC of 0.8 to 3.1 μM against X. axonopodis pv. vesicatoria, 21 peptides MIC of 1.6 to 6.2 μM against P. syringae pv. syringae and six peptides MIC of 6.2 to 12.5 μM against E. amylovora. Regarding the hemolysis, in general, Trp derivatives displayed a percentage of hemolysis comparable to that of their Phe analogues. Notably, 49 Trp-containing cyclic peptides showed a hemolysis ≤ 20% at 125 μM. The peptides with the best biological activity profile were c(LKKKLWKKLQ) (BPC086W) and c(LKKKKWLLKQ) (BPC108W), which displayed MIC values ranging from 0.8 to 12.5 μM and a hemolysis ≤ 8% at 125 μM. Therefore, it is evident that these Trp sequences constitute promising candidates for the development of new agents for use in plant protection.
