Cyclodextrin derivatives prepared to mimic a membrane active antibacterial peptide polymyxin B strongly permeabilized bacterial membrane and inhibited bacterial proliferation.

The horseshoe crab peptide polyphemusin I possesses high antimicrobial activity, but its mechanism of action is as yet not well defined. Using a biotin-labeled polyphemusin I analogue and confocal fluorescence microscopy, we showed that the peptide accumulates in the cytoplasm of wild-type Escherichia coli within 30 min after addition without causing substantial membrane damage.

The antimicrobial activity of the collective molecules comprising human milk reflects an evolutionarily successful paradigm for preventing and limiting microbial infection. Understanding the molecules that participate in this process and how they work can yield insight into potentially new antimicrobial therapies. Upon proteolytic processing, antimicrobial peptides can be derived from milk prot...

BACKGROUND The antimicrobial peptide LL-37 is a significant molecule of innate immunity and recent studies indicate that it plays an important role in maintaining oral health. Yet limited knowledge exists on its role in oral diseases and oral lichen planus (OLP) in particular. OBJECTIVE The study aimed to examine: 1) the salivary concentration of LL-37 in patients with OLP and healthy subject...

Lung tissue removed from neonatal calves with acute Mannheimia haemolytica pneumonia showed that rapid up-regulation of the basal mRNA expression of tracheal antimicrobial peptide (TAP), NF-kappa B, and intercellular adhesion molecule 1 occurred after infection; TAP and interleukin 8 expression were highly correlated. This work suggests that the coordinated expression of beta-defensin and infla...

The cathelicidin antimicrobial peptide LL-37 is an important component of our first line of defense against bacterial infections. Induction of antimicrobial peptides such as LL-37 might provide a novel approach in treating bacterial infections, where conventional antibiotics fail. To investigate the effect of 4-phenylbutyrate (PBA) on antimicrobial peptide expression, we initially treated vario...

The lipopolysaccharide binding domain (LBD) in anti-lipopolysaccharide factor (ALF) is the main functional element of ALF, which exhibits antimicrobial activities. Our previous studies show that the peptide LBDv, synthesized based on the modified sequence of LBD (named LBD2) from FcALF2, exhibited an apparently enhanced antimicrobial activity. To learn the prospect of LBDv application, the char...

Conventional analyses distinguish between antimicrobial peptides by differences in amino acid sequence. Yet structural paradigms common to broader classes of these molecules have not been established. The current analyses examined the potential conservation of structural themes in antimicrobial peptides from evolutionarily diverse organisms. Using proteomics, an antimicrobial peptide signature ...

Antimicrobial peptides are expressed in the skin of amphibians and are used to prevent infection by microorganisms. Frog species store distinct collections of antimicrobial peptides that show variation in size, charge, conformation, and bactericidal activity, and so the evolution of antimicrobial peptide gene families may reflect the adaptive diversification of these loci. We examined the molec...

The antimicrobial activity of the anionic peptide, AP1 (GEQGALAQFGEWL), was investigated. AP1 was found to kill Staphylococcus aureus with an MLC of 3mM and to induce maximal surface pressure changes of 3.8 mN m(-1) over 1200s in monolayers formed from lipid extract of S. aureus membranes. FTIR spectroscopy showed the peptide to be alpha-helical (100%) in the presence of vesicles formed from th...