Ion channels form a group of membrane proteins that pass ions through a pore beyond the energy barrier of the lipid bilayer. The structure of the transmembrane segment of membrane proteins is influenced by the charges and the hydrophobicity of the surrounding lipids and the pressure on its surface. A mechanosensitive channel is specifically designed to change its conformation in response to cha...

Proteins are known to form functional clusters in plasma membranes. In order to identify individual proteins within clusters we developed a method to visualize by atomic force microscopy (AFM) the cytoplasmic surface of native plasma membrane, excised from Xenopus laevis oocyte and spread on poly-L-lysine coated glass. After removal of the vitelline membrane intact oocytes were brought in conta...

The composition of the lipid bilayer is increasingly being recognised as important for the regulation of integral membrane protein folding and function, both in vivo and in vitro. The folding of only a few membrane proteins, however, has been characterised in different lipid environments. We have refolded the small multidrug transporter EmrE in vitro from a denatured state to a functional prote...

The incorporation of concanamycin A, a potent inhibitor of vacuolar ATPases, into membranes of dimyristoyl phosphatidylcholine has been studied by using EPR of spin-labelled lipid chains. At an inhibitor/lipid ratio of 1:1 mol/mol, concanamycin A broadens the chain-melting transition of the phospholipid bilayer membrane, and effects the lipid chain motion in the fluid phase. The outer hyperfine...

Bacillus thuringiensis (Bt) Cyt2Aa2 showed toxicity against Dipteran insect larvae and in vitro lysis activity on several cells. It has potential applications in the biological control of insect larvae. Although pore-forming and/or detergent-like mechanisms were proposed, the mechanism underlying cytolytic activity remains unclear. Analysis of the haemolytic activity of Cyt2Aa2 with osmotic sta...

Cell membranes possess a complex three-dimensional architecture, including nonrandom lipid lateral organization within the plane of a bilayer leaflet, and compositional asymmetry between the two leaflets. As a result, delineating the membrane structure-function relationship has been a highly challenging task. Even in simplified model systems, the interactions between bilayer leaflets are poorly...

Transport proteins are essential for cells in allowing the exchange of substances between and their environment across lipid bilayer forming a tight barrier. Membrane lipids modulate function transmembrane such as transporters two ways: Lipids tightly specifically bound to transport addition they from bulk proteins. This overview summarizes currently available information at ultrastructural lev...

Hereditary spherocytosis and elliptocytosis are the two most common inherited red cell membrane disorders resulting from mutations in genes encoding various red cell membrane and skeletal proteins. Red cell membrane, a composite structure composed of lipid bilayer linked to spectrin-based membrane skeleton is responsible for the unique features of flexibility and mechanical stability of the cel...

Sum frequency generation (SFG) vibrational spectroscopy was used to study interactions between solid-supported lipid bilayers mimicking microbial and erythrocyte cellular membranes and synthetic antimicrobial arylamide oligomers named 2, 3, and 4, designed with the facial amphiphilicity common to naturally occurring antimicrobial peptides. The three compounds have the same backbone structure bu...

173 news & views t he space occupied by living organisms is determined by membranes. Each cell is delimited by a membrane, and additional membranes form the functional hierarchy of compartments packed within it. The intracellular compartments, for example vesicles and organelles, define the spatial organization of metabolic pathways, thus providing the topological framework for cellular life. R...