The outer membrane of Gram-negative bacteria is a unique asymmetric lipid bilayer composed of phospholipids (PLs) in the inner leaflet and lipopolysaccharides (LPSs) in the outer leaflet. Its function as a selective barrier is crucial for the survival of bacteria in many distinct environments, and it also renders Gram-negative bacteria more resistant to antibiotics than their Gram-positive coun...

Phospholipid bilayers are the basic structural element of biological membranes. They separate the various cell compartments found in eukaryotic cells and form the outer barrier (cell membrane or plasma membrane) of eukaryotic and prokaryotic cells separating the cytoplasm from the extra-cellular space. The composition of phospholipid bilayers varies with the cell type and function of the membra...

The membrane interactions of the antimicrobial peptides aurein 1.2 and caerin 1.1 were observed by (31)P and (2)H solid-state NMR and circular dichroism spectroscopy. Both peptides were relatively unstructured in water. In the presence of dimyristoylphosphatidylcholine (DMPC) and mixed DMPC and dimyristoylphosphatidylglycerol (DMPG) vesicles, both peptides displayed a considerable increase in h...

Low-intensity ultrasound can modulate action potential firing in neurons in vitro and in vivo. It has been suggested that this effect is mediated by mechanical interactions of ultrasound with neural cell membranes. We investigated whether these proposed interactions could be reproduced for further study in a synthetic lipid bilayer system. We measured the response of protein-free model membrane...

Highly curved bilayer lipid membranes make up the shell of many intra- and extracellular compartments, including organelles and vesicles. Using all-atom molecular dynamics simulations, we show that increasing the density of lipids in the bilayer membrane can induce the membrane to form a curved shape.

Lipid analysis confirms that not only membrane proteins but also some of the aminophospholipids are cross-linked. This cross-linking of lipid head groups also does not affect sterol uptake, but the phospholipids which are cross-linked are located mainly in the inner leaflet of the bilayer. This is consistent with the finding (P. J. McCabe & C. Green, unpublished work) that uptake of extra chole...

Model biological membranes are becoming increasingly important for studying fundamental biophysical phenomena and developing membrane-based devices. To address the anticipated problem of non-physiological interactions between membrane proteins and substrates seen in "solid-supported lipid bilayers" that are formed directly on hydrophilic substrates, we have developed a polymer-tethered lipid bi...

The red blood cell (RBC) membrane is a complex mixture of lipids and proteins. Hundreds of phospholipid molecular species spontaneously arrange themselves in a lipid bilayer and move rapidly in the plane as well as across the bilayer in a dynamic but highly organized fashion. Areas enriched in certain lipids determine proper protein function. Phospholipids are asymmetrically distributed across ...

Using unbiased atomic-detailed molecular dynamics simulations, the C-terminal fragments of TDP-43 are observed to aggregate and form disordered-toroidal pores in a lipid bilayer. Cytotoxicity of TDP-43 may be inferred from the observation that the membrane pores catalyze lipid flip-flop between bilayer leaflets and conduct water at high rates.

Unfolded outer membrane protein A (OmpA) of Escherichia coli spontaneously inserts and refolds into lipid bilayers upon dilution of denaturing urea. In the accompanying paper, we have developed a new technique, time-resolved distance determination by fluorescence quenching (TDFQ), which is capable of monitoring the translocation across lipid bilayers of fluorescence reporter groups such as tryp...