Tryptophan-Containing Cyclic Decapeptides with Activity against Plant Pathogenic Bacteria

Abstract

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.

Antimicrobial activity of linear lipopeptides derived from BP100 towards plant pathogens

“…Antimicrobial and plant defense elicitor peptides have been the object of an intense research and development as new candidates for plant protection against fungal and bacterial diseases [ 7 – 12 ]. Lipopeptides are a subclass of antimicrobial peptides that are considered attractive candidates for the development of new peptide-based pesticides [ 13 – 15 ].…”

Evaluation of Three Antimicrobial Peptides Mixtures to Control the Phytopathogen Responsible for Fire Blight Disease

“…Although most studies on the potential application of AMPs against phytopathogenic microorganisms have been focused on the use of individual peptides [36][37][38][39], several works have been recently assessing mixtures of AMPs with other bactericidal components, such as, lysozyme [40], antibiotics [41], and other different AMPs [15,26,42]. Even though the latter has been showing promising results, up to date there is only one study that has explored the mixture of different AMPs, namely, peptides flg15 and BP16, to control the phytopathogen E. amylovora [15].…”

Cell Membrane-Interrupting Antimicrobial Peptides from Isatis indigotica Fortune Isolated by a Bacillus subtilis Expression System

“…To date, most of the research related to AMPs has been focused on extraction, separation, purification, and synthesis of AMPs, as well as some exploration of resistance mechanisms [23]. For the isolation of candidate AMPs, there are two main methods.…”