Thermodynamic Study on Biomimetic Bacterial Membranes.

The presented studies were aimed at determining the interactions in model membranes (Langmuir monolayers) created of phospholipids (PL) isolated from bacteria cultured with (PL + choline) or without (PL - choline) choline and to describe the impact of an antimicrobial peptide, human cathelicidin LL-37, on PL's monolayer behavior. The addition of choline to the growth medium influenced the mutual proportions of phospholipids extracted from . Four classes of phospholipids-phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), cardiolipin (CL), and their mixtures-were used to register compression isotherms with or without the LL-37 peptide in the subphase.

Susceptibility of Membrane-Derived Phospholipids to the Peptide Action of Antimicrobial LL-37-Langmuir Monolayer Studies.

LL-37 is the only member of the cathelicidin-type host defense peptide family in humans. It exhibits broad-spectrum bactericidal activity, which represents a distinctive advantage for future therapeutic targets. The presence of choline in the growth medium for bacteria changes the composition and physicochemical properties of their membranes, which affects LL-37's activity as an antimicrobial agent.

Insight into the Mechanism of Interactions between the LL-37 Peptide and Model Membranes of Bacteria.

is a fastidious, Gram-negative bacterium known to be the etiological agent of atypical community-acquired pneumonia. The human cathelicidin LL-37 exhibits a dose-dependent bactericidal effect on . The LL-37 peptide at the concentration of 10 µM causes the bacteria to become viable but not cultured.

Physicochemical Characteristics of Model Membranes Composed of Lipids.

is one of the species belonging to the genus , which causes atypical community-acquired pneumonia. The most important virulence factors that enable the bacteria to colonize the host organism are associated with the cell surface. Lipids building the cell envelope are crucial not only for the membrane integrity of but also by virtue of being a dynamic site of interactions between the pathogen and the metabolites supplied by its host.