Supported lipid bilayers containing phosphatidylcholine headgroups are observed to undergo reorganization from a 2D fluid, lipid bilayer assembly into an array of complex 3D structures upon exposure to extreme pH environments. These conditions induce a combination of molecular packing and electrostatic interactions that can create dynamic morphologies of highly curved lipid membrane structures....

A mixed bilayer of cholesterol and dimyristoylphosphatidylcholine has been formed on a gold-coated block of quartz by fusion of small unilamellar vesicles. The formation of this bilayer lipid membrane on a conductive surface allowed us to study the influence of the support's surface charge on the structure and hydration of the bilayer lipid membrane. We have employed electrochemical measurement...

The 2H NMR transverse relaxation rates of a deuterated phospholipid bilayer reflect slow motions in the bilayer membrane. A study of dimyristoyl lecithin specifically deuterated at several positions of the hydrocarbon chains indicates that these motions are cooperative and are confined to the hydrocarbon chains of the lipid bilayer. However, lipid head group interactions do play an important ro...

A cell membrane can be simply regarded as composite material consisting of lipid bilayer, membrane cytoskeleton beneath lipid bilayer, and proteins embedded in lipid bilayer and linked with membrane cytoskeleton if one only concerns its mechanical properties. In this Chapter, above all, the authors give a brief introduction to some important work on mechanical properties of lipid bilayers follo...

Triglycerides have a limited solubility, around 3%, in phosphatidylcholine lipid bilayers. Using millisecond-scale course grained molecular dynamics simulations, we show that the model lipid bilayer can accommodate a higher concentration of triolein (TO) than earlier anticipated, by sequestering triolein molecules to the bilayer center in the form of a disordered, isotropic, mobile neutral lipi...

At submicromolar concentrations, capsaicin specifically activates the TRPV1 receptor involved in nociception. At micro- to millimolar concentrations, commonly used in clinical and in vitro studies, capsaicin also modulates the function of a large number of seemingly unrelated membrane proteins, many of which are similarly modulated by the capsaicin antagonist capsazepine. The mechanism(s) under...

The modulation of the properties and function of cell membranes by small volatile substances is important for many biomedical applications. Despite available experimental results, molecular mechanisms of action of inhalants and organic solvents, such as acetone, on lipid membranes remain not well understood. To gain a better understanding of how acetone interacts with membranes, we have perform...

A set of 49 protein nanopore-lipid bilayer systems was explored by means of coarse-grained molecular-dynamics simulations to study the interactions between nanopores and the lipid bilayers in which they are embedded. The seven nanopore species investigated represent the two main structural classes of membrane proteins (alpha-helical and beta-barrel), and the seven different bilayer systems rang...

The major permeability barrier in any membrane is the lipid bilayer structure, and its barrier property is inversely correlated with its fluidity. Bacteria cannot make this membrane much less fluid or it will start to interfere with the normal functions of the membrane proteins, so some bacteria have constructed an additional structure that surrounds the cell outside the cytoplasmic membrane. A...

The ionization states of individual amino acid residues of membrane proteins are difficult to decipher or assign directly in the lipid-bilayer membrane environment. We address this issue for lysines and arginines in designed transmembrane helices. For lysines (but not arginines) at two locations within dioleoyl-phosphatidylcholine bilayer membranes, we measure pK(a) values below 7.0. We find th...