Development of a novel short 12-meric papiliocin-derived peptide that is effective against Gram-negative sepsis

Abstract

The development of novel peptide antibiotics with potent activity against multidrug-resistant Gram-negative bacteria and anti-septic activity is urgently needed. In this study, we designed short, 12-meric antimicrobial peptides by substituting amino acids from the N-terminal 12 residues of the papiliocin (Pap12-1) peptide to alter cationicity and amphipathicity and improve antibacterial activity and bacterial membrane interactions. Pap12-6, with an amphipathic α-helical structure and Trp 12 at the C-terminus, showed broad-spectrum antibacterial activity, especially against multidrug-resistant Gram-negative bacteria. Dye leakage, membrane depolarization, and electron microscopy data proved that Pap12-6 kills bacteria by permeabilizing the bacterial membrane. Additionally, Pap12-6 significantly reduced the secretion of NO, TNF-α, and IL-6 and secreted alkaline phosphatase reporter gene activity confirmed that Pap12-6 shows anti-inflammatory activity via a TLR4-mediated NF-κB signaling pathway. In a mouse sepsis model, Pap12-6 significantly improved survival, reduced bacterial growth in organs, and reduced LPS and inflammatory cytokine levels in the serum and organs. Pap12-6 showed minimal cytotoxicity towards mammalian cells and controlled liver and kidney damage, proving its high bacterial selectivity. Our results suggest that Pap12-6 is a promising peptide antibiotic for the therapeutic treatment of Gram-negative sepsis via dual bactericidal and immunomodulatory effects on the host.

Target Proteins of Phloretin for Its Anti-Inflammatory and Antibacterial Activities Against Propionibacterium acnes-Induced Skin Infection

“…SEAP assay was used to evaluate the effect of phloretin on TLR2 signaling in HEK-Blue TM -hTLR2 cells by monitoring the activation of NF-kB [29]. SEAP assay was performed with phloretin and CU-CPT22 (Hexyl-3,4,6-trihydroxy-2-methoxy-5-oxo-5H-benzo[7]annulene-8-carboxylate) to a maximum concentration of 50 µM before the induction of cytotoxicity.…”

A Novel Peptide Antibiotic, Pro10-1D, Designed from Insect Defensin Shows Antibacterial and Anti-Inflammatory Activities in Sepsis Models

“…For example, papiliocin with 37 amino acids shows high antibacterial activity against gram-negative bacteria; however, 37 residues can make the production costs high [ 61 ]. Previously, we designed 12-meric AMP analogs from the N-terminus of papiliocin with antiseptic activity against gram-negative infections [ 62 , 63 ].…”

“…Endotoxin levels in the serum contents were quantified according to the kit protocol using Pierce LAL Chromogenic Endotoxin Quantitation Kit (Thermo Fisher Scientific, MA, USA). The levels of AST, ALT, and BUN in serum and the inflammatory cytokine levels in the serum or lung lysates were quantified as described previously [ 63 ].…”

New Antibacterial Peptides from the Freshwater Mollusk Pomacea poeyana (Pilsbry, 1927)

“…The selectivity of AMPs is attributed to their affinities for the cytoplasmic membranes of different cells and is determined by physiochemical properties such as hydrophobicity (H), hydrophobic moment (uHrel), cationicity, amphipaticity etc. [ 51 ].…”