Disruption of lipid domain organization in monolayers of complex yeast lipid extracts induced by the lysophosphatidylcholine analogue edelfosine in vivo.

The lysophosphatidylcholine analogue edelfosine is a potent antitumor and antiparasitic drug that targets cell membranes. Previous studies have shown that edelfosine alters membrane domain organization inducing internalization of sterols and endocytosis of plasma membrane transporters. These early events affect signaling pathways that result in cell death.

Visualizing a multidrug resistance protein, EmrE, with major bacterial lipids using Brewster angle microscopy.

Understanding lipid-protein interactions to enhance our knowledge of membrane architecture is a critical step in the development of novel therapeutic measures to respond to the drastic rise of drug resistant microorganisms. Escherichia coli contains a small archetypal inner membrane multidrug resistance protein, EmrE, that must multimerize to be functional but this multimerization is difficult to demonstrate in vivo. We studied three major E.

Real-time imaging of lipid domains and distinct coexisting membrane protein clusters.

A detailed understanding of biomembrane architecture is still a challenging task. Many in vitro studies have shown lipid domains but much less information is known about the lateral organization of membrane proteins because their hydrophobic nature limits the use of many experimental methods. We examined lipid domain formation in biomimetic Escherichia coli membranes composed of phosphatidylethanolamine and phosphatidylglycerol in the absence and presence of 1% and 5% (mol/mol) membrane multidrug resistance protein, EmrE.

Toluene depletion in produced oil contributes to souring control in a field subjected to nitrate injection.

Souring in the Medicine Hat Glauconitic C field, which has a low bottom-hole temperature (30 °C), results from the presence of 0.8 mM sulfate in the injection water. Inclusion of 2 mM nitrate to decrease souring results in zones of nitrate-reduction, sulfate-reduction, and methanogenesis along the injection water flow path.

Real-time imaging of interactions between dipalmitoylphosphatidylcholine monolayers and gelatin based nanoparticles using Brewster angle microscopy.

Given the current interest in the pulmonary route for targeted drug delivery, assessing the impact of drug delivery vehicles on the surfactant layer lining the surface of the lung alveoli is critical. As gelatin-based nanoparticles are one such vehicle, this study addresses their interaction with the major saturated phospholipid component of native lung surfactant, dipalmitoylphosphatidylcholine (DPPC). Nanoparticles are colloidal particles in the size range of 1 to 1000 nm that are presently investigated for site-specific drug delivery in the emerging field of nanomedicine.

Induction of non-lamellar lipid phases by antimicrobial peptides: a potential link to mode of action.

Antimicrobial peptides are naturally produced by numerous organisms including insects, plants and mammals. Their non-specific mode of action is thought to involve the transient perturbation of bacterial membranes but the molecular mechanism underlying the rearrangement of the lipid molecules to explain the formation of pores and micelles is still poorly understood. Biological membranes mostly adopt planar lipid bilayers; however, antimicrobial peptides have been shown to induce non-lamellar lipid phases which may be intimately linked to their proposed mechanisms of action.