Table 1 Screening of LL-37–derived peptides reveals peptides with improved bactericidal activity against S. aureus.

Bactericidal activity in phosphate-buffered saline (PBS) and in PBS with 50% human plasma. Results are expressed as the 99.9% lethal concentration (LC99.9), that is, the lowest peptide concentration that resulted in ≥99.9% killing of S. aureus JAR060131. Results are medians (and ranges) of three to four independent experiments. If no range is indicated, then the LC99.9 was identical in all experiments. The most effective synthetic antimicrobial and antibiofilm peptides (SAAPs) are depicted in bold.

PeptideSequenceLC99.9 (μM)
PBS50% plasma
LL-37LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES1.6(1.6–6.4)>204.8
P139LKKLWKRVFRIWKRIFRYLKRPVR1.6(0.8–1.6)51.2
P140LRRLWKRLVRIIKRIYRQLKRPVR1.638.4(25.6–51.2)
P141LRRLYKRVFRLLKRWWRYLKRPVR1.6(0.8–1.6)38.4(25.6–51.2)
P142LRRLWKRLVKILKRWFRYLRRPVR1.6(0.8–1.6)51.2(51.2–102.4)
P143LRRLYKRVVKLWKRLFRQLRRPVR1.6(1.6–3.2)51.2(51.2–102.4)
P144LKKLYKRVAKIWKRWIRYLKKPVR1.638.4(25.6–51.2)
P145(SAAP-145)LKRLYKRLAKLIKRLYRYLKKPVR1.6(0.8–1.6)12.8(12.8–25.6)
P146LKKLYKRLFKILKRILRYLRKPVR1.2(0.8–1.6)51.2(25.6–51.2)
P147LKKLWKRLARLLKRFIRQLRRPVR1.651.2(25.6–51.2)
P148(SAAP-148)LKRVWKRVFKLLKRYWRQLKKPVR1.612.8(12.8–25.6)
P149LKKVYKRLARLLKRYIRYLRRPVR1.625.6(25.6–51.2)
P150LKKVWKRVARLIKRWFRYLRRPVR1.625.6(25.6–51.2)
P151LKKLYKRLFKLWKRLYRYLKKPVR1.625.6(25.6–51.2)
P152LRRVYKRLARLIKRYLRQLKKPVR1.6(1.6–3.2)25.6
P153LRKLWKRVVKIWKRYLRQLRRPVR1.619.2(12.8–25.6)
P154LRKLWKRLAKIIKRLYRYLRRPVR1.6(0.8–1.6)25.6(12.8–25.6)
P155LKKVYKRVARLIKRLFRYLKRPVR1.625.6(12.8–25.6)
P156LRRLWKRLVKLWKRFFRYLKKPVR1.651.2(51.2–102.4)
P157LKKVWKRVFRILKRFLRYLKRPVR1.6(0.8–1.6)51.2(25.6–51.2)
P158LRRVYKRLFRLWKRIIRQLRRPVR1.625.6(12.8–25.6)
P159(SAAP-159)LKRLYKRVFRLLKRYYRQLRRPVR1.6(1.6–3.2)12.8
P160LKKLWKRLARLWKRIIRQLKKPVR1.6(1.6–3.2)51.2(25.6–51.2)
P161LRRVWKRVARIIKRLYRYLKRPVR1.6(1.6–3.2)19.2(12.8–25.6)
P162LKRLWKRLFKILKRYYRYLRRPVR1.625.6(25.6–51.2)
P163LRRLWKRVFKIIKRLFRQLKKPVR1.6(0.8–1.6)19.2(12.8–25.6)
P276(SAAP-276)LKRVWKAVFKLLKRYWRQLKKPVR0.86.4(6.4–12.8)