Structure of lipid bilayers

Eating five servings of fruits and vegetables per day! This is what is highly recommended and heavily advertised nowadays to the general public to stay fit and healthy! Drinking green tea on a regular basis, eating chocolate from time to time, as well as savoring a couple of glasses of red wine per day have been claimed to increase life expectancy even further! Why? The answer is in fact still under scientific scrutiny, but a particular class of compounds naturally occurring in fruits and vegetables is considered to be crucial for the expression of such human health benefits: the polyphenols! What are these plant products really? What are their physicochemical properties? How do they express their biological activity? Are they really valuable for disease prevention? Can they be used to develop new pharmaceutical drugs? What recent progress has been made toward their preparation by organic synthesis? This Review gives answers from a chemical perspective, summarizes the state of the art, and highlights the most significant advances in the field of polyphenol research.

Plant Polyphenols: Chemical Properties, Biological Activities, and Synthesis

Intermolecular And Surface Forces

CHARMM-GUI Membrane Builder, http://www.charmm-gui.org/input/membrane, is a web-based user interface designed to interactively build all-atom protein/membrane or membrane-only systems for molecular dynamics simulations through an automated optimized process. In this work, we describe the new features and major improvements in Membrane Builder that allow users to robustly build realistic biological membrane systems, including (1) addition of new lipid types, such as phosphoinositides, cardiolipin (CL), sphingolipids, bacterial lipids, and ergosterol, yielding more than 180 lipid types, (2) enhanced building procedure for lipid packing around protein, (3) reliable algorithm to detect lipid tail penetration to ring structures and protein surface, (4) distance-based algorithm for faster initial ion displacement, (5) CHARMM inputs for P21 image transformation, and (6) NAMD equilibration and production inputs. The robustness of these new features is illustrated by building and simulating a membrane model of the polar and septal regions of E. coli membrane, which contains five lipid types: CL lipids with two types of acyl chains and phosphatidylethanolamine lipids with three types of acyl chains. It is our hope that CHARMM-GUI Membrane Builder becomes a useful tool for simulation studies to better understand the structure and dynamics of proteins and lipids in realistic biological membrane environments. © 2014 Wiley Periodicals, Inc.

CHARMM-GUI Membrane Builder Toward Realistic Biological Membrane Simulations

Cholesterol and the cell membrane.

The effect of sterols from mammals, plants, fungi, and bacteria on model and natural membrane dynamics are reviewed, in the frame of ordering-disordering properties of membranes. It is shown that all sterols share a common property: the ability to regulate dynamics in order to maintain membranes in a microfluid state where it can convey important biological processes. Depending on the sterol class, this property is modulated by molecular modifications that have occurred during evolution. The role of sterols in rafts, antibiotic complexes, and in protecting membranes from the destructive action of amphipathic toxins is also discussed.

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Sterols and membrane dynamics

Restatement of order parameters in biomembranes: calculation of C-C bond order parameters from C-D quadrupolar splittings

Structural and dynamical details of cholesterol-lipid interaction as revealed by deuterium NMR

Dynamics of phosphate head groups in biomembranes. Comprehensive analysis using phosphorus-31 nuclear magnetic resonance lineshape and relaxation time measurements

Erick J. Dufourc

Papers

Sterols and membrane dynamics

Restatement of order parameters in biomembranes: calculation of C-C bond order parameters from C-D quadrupolar splittings

Structural and dynamical details of cholesterol-lipid interaction as revealed by deuterium NMR

Dynamics of phosphate head groups in biomembranes. Comprehensive analysis using phosphorus-31 nuclear magnetic resonance lineshape and relaxation time measurements

The Metabolic Architecture of Plant Cells STABILITY OF CENTRAL METABOLISM AND FLEXIBILITY OF ANABOLIC PATHWAYS DURING THE GROWTH CYCLE OF TOMATO CELLS