A novel mechanism for membrane modulation of transmembrane protein structure, and consequently function, is suggested in which mismatch between the hydrophobic surface of the protein and the hydrophobic interior of the lipid bilayer induces a flexing or bending of a transmembrane segment of the protein. Studies on model hydrophobic transmembrane peptides predict that helices tilt to submerge th...

The simplest cell-like structure, the lipid bilayer vesicle, can respond to mechanical deformation by elastic membrane dilation/thinning and curvature changes. When a protein is inserted in the lipid bilayer, an energetic cost may arise because of hydrophobic mismatch between the protein and bilayer. Localized changes in bilayer thickness and curvature may compensate for this mismatch. The pept...

Intrinsic membrane proteins are solvated by a shell of lipid molecules interacting with the membrane-penetrating surface of the protein; these lipid molecules are referred to as annular lipids. Lipid molecules are also found bound between transmembrane α-helices; these are referred to as non-annular lipids. Annular lipid binding constants depend on fatty acyl chain length, but the dependence is...

In eukaryotic cells, the membranes of different intracellular organelles have different lipid composition, and various biomembranes show an asymmetric distribution of lipid types across the membrane bilayer. Membrane lipid organization reflects a dynamic equilibrium of lipids moving across the bilayer in both directions. In this review, we summarize data supporting the role of specific membrane...

docosahexaenoic acid (DHA, 22:6) and eicosapentaenoic acid (EPA, 20:5), is linked to the prevention of diseases such as cancer and heart disease, and is needed for neurological and brain development. We have recently attempted to use these functional fatty acids as an absorption enhancer and have reported that intestinal absorption of insulin and vancomycin increase when administered with these...

A comparative study of the lipid bilayer phase status and structure of the outer membrane of free-living Bradyrhizobium strain 359a (Nod(+)Fix(+)) and 400 (Nod(+)FixL) or Rhizobium leguminosarum 97 (Nod(+)Fix(+), effective) and 87 (Nod(+)FixL, ineffective) has been carried out. Also, the effect of the symbiotic pair combination on the lipid bilayer structure of the bacteroid outer membrane and ...

For four decades, since W. Helfrich's pioneering study of smectic A liquid crystals in 1973, continuum elastic models (CEMs) have been employed as tools to understand the energetics of protein-induced lipid bilayer deformations. Among the assumptions underlying this use is that all relevant protein-lipid interactions can be included in the continuum representation of the protein-bilayer interac...

Membranes of all cells contain a significant fraction of phospholipids arranged in a self-assembled bilayer. This lipid bilayer forms a robust barrier to ions, proteins and other molecules, and separates the inside of the cell from the outside (plasma membrane), or compartmentalizes the cells (mitochondria). Embedded in the lipid bilayers are a large variety of glycoproteins, globular proteins,...

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...

iMembrane is a homology-based method, which predicts a membrane protein's position within a lipid bilayer. It projects the results of coarse-grained molecular dynamics simulations onto any membrane protein structure or sequence provided by the user. iMembrane is simple to use and is currently the only computational method allowing the rapid prediction of a membrane protein's lipid bilayer inser...