Antimicrobial activity of synthetic cationic peptides and lipopeptides derived from human lactoferricin against Pseudomonas aeruginosa planktonic cultures and biofilms

Table 1 Relevant characteristics of peptides and lipopeptides used in this study

Peptides^a	Sequences		MIC^b (μg/ml)	MBC^c (μg/ml)	T_3log ^d at different concentrations higher their MICs (minutes)			Hydrophobicity^e Δg_woct (kcal/mol)
Peptides^a	Sequences		MIC^b (μg/ml)	MBC^c (μg/ml)	1X	2X	4X	Hydrophobicity^e Δg_woct (kcal/mol)
LF11-215		FWRIRIRR	64	128	>360	28	10	5,5
O-LF11-215	octanoyl	FWRIRIRR	32	32	17	21	10	3,2
DI-MB-LF11-215	2,2-dimethylbutanoyl	FWRIRIRR	16	16	17	11	10	3,2
6-MO-LF11-215	6-methyloctanoyl	FWRIRIRR	64	64	34	11	10	3,2
LF11-322		PFWRIRIRR	32	64	>360	11	11	5,64
DI-MB-LF11-322	2,2-dimethylbutanoyl	PFWRIRIRR	32	32	12	11	10	3,34
6-MO-LF11-322	6-methyloctanoyl	PFWRIRIRR	64	64	41	39	19	3,34
LF11-324		PFFWRIRIRR	8	8	113	13	10	3,93
LF11-227		FWRRFWRR	64	64	13	12	10	3,94
O-LF11-227	octanoyl	FWRRFWRR	128	128	10	10	10	1,64
6-MO-LF11-227	6-methyloctanoyl	FWRRFWRR	128	128	10	10	10	1,64

^a: Peptide derivatives from human lactoferricin (based on residues 21–31), C-termini is amidated in all peptides; ^b: Minimal inhibitory concentration against PAO1 planktonic cells; ^c: Minimal bactericidal concentration against PAO1 planktonic cells; ^d: T_3log is defined as the time needed to decrease 3 logs the initial inoculum determined in the killing curves assays. Relevant peptide modifications are shown in bold. ^e:Peptide hydrophobicity is expressed as transfer free energy of peptides from water to n-octanol (ΔG_woct) using Wimley-White octanol whole-residue scales [59] taking into account end group contributions, i.e. amidation of the C-termini and where appropriate acylation of N-termini. Latter was approximated by an acetyl group. Calculations were performed using MPEx [60]. Note that this parameter is inversely proportional to hydrophobicity

ISSN: 1471-2180