The objective of this research is to investigate structural and dynamical properties of aqueous solutions next to and between surfaces of biological macromolecules, particularly membranes.

Due to recent advancements in the development of numerical algorithms and computational hardware, computer simulations of biological membranes, often requiring use of substantial computational resources, are now reaching a mature stage. Since molecular processes in membranes occur on a multitude of spatial and time scales, molecular simulations of membranes can also serve as a testing ground for use of multi-scale simulation techniques. This book addresses some of the important issues related to understanding properties and behavior of model biological membranes and it Shows how simulations improve our understanding of biological membranes and makes connections with experimental results. Presents a careful discussion of the force fields used in the membrane simulations including detailed all-atom fields and coarse-grained fields. Presents a continuum description of membranes. Discusses a variety of issues such as influence of membrane surfaces on properties of water, interaction between membranes across water, nanoparticle permeation across the membrane, action of anesthetics and creation of inhomogeneous regions in membranes. Discusses important methodological issues when using simulations to examine phenomena such as pore creation and permeation across membranes. Discusses progress recently achieved in modeling bacterial membranes. It will be a valuable resource for graduate students, researchers and instructors in biochemistry, biophysics, pharmacology, physiology, and computational biology.

This book is about the importance of water in determining the structure, stability and responsive behavior of biological membranes. Water confers to lipid membranes unique features in terms of surface and mechanical properties. The analysis of the hydration forces, plasticiser effects, controlled hydration, formation of microdomains of confined water suggests that water is an active constituent in a water-lipid system. The chapters describe water organization at the lipid membrane–water interphase, the water penetration, the long range water structure in the presence of lipid membranes by means of X-ray and neutron scattering, general polarization, fluorescent probes, ATR-FTIR and near infrared spectroscopies, piezo electric methods, computer simulation and surface thermodynamics. Permeation, percolation, osmotic stress, polarization, protrusion, sorption, hydrophobicity, density fluctuations are treated in detail in self-assembled bilayers. Studies in lipid monolayers show the correlation of surface pressure with water activity and its role in peptide and enzyme interactions. The book concludes with a discussion on anhydrobiosis and the effect of water replacement in microdomains and its consequence for cell function. New definitions of lipid/water interphases consider water not only as a structural-making solvent but as a mediator in signalling metabolic activity, modulating protein insertion and enzymatic activity, triggering oscillatory reactions and functioning of membrane bound receptors. Since these effects occur at the molecular level, membrane hydration appears fundamental to understand the behavior of nano systems and confined environments mimicking biological systems. These insights in structural, thermodynamical and mechanical water properties give a base for new paradigms in membrane structure and function for those interested in biophysics, physical chemistry, biology, bio and nano medicine, biochemistry, biotechnology and nano sciences searching for biotechnological inputs in human health, food industry, plant growing and energy conversion.

This volume collects a number of the invited lectures and a few selected contrib utions presented at the International Symposium on Structure and Dynamics of Nucleic Acids, Proteins and Membranes held August 31st through September 5th, 1986, in Riva del Garda, Italy. The title of the conference as well as a number of the topics covered represent a continuation of two previous conferences, the first held in 1982 at the University of California in San Diego, and the second in 1984 in Rome at the Accademia dei Lincei. These two earlier conferences have been documented in Structure and Dynamics: Nucleic Acids and Proteins, edited by E. Clementi and R. H. Sarma, Adenine Press, New York, 1983, and Structure and Motion: Membranes, Nucleic Acids and Proteins, edited by E. Clementi, G. Corongiu, M. H. Sarma and R. H. Sarma, Adenine Press, New York, 1985. At this conference in Riva del Garda we were very hesitant to keep the name of the conference the same as the two previous ones. Indeed, a number of topics discussed in this conference were not included in the previous ones and even the emphasis of this gathering is only partly reflected in the conference title. An alternative title would have been Structure and Dynamics of Nucleic Acids, Proteins, and Higher Functions, or, possibly, "higher components" rather than "higher functions.

This thesis presents a highly innovative study of the ultrafast structural and vibrational dynamics of hydrated phospholipids, the basic constituents of cell membranes. As a novel approach to the water-phospholipid interface, the author studies phosphate vibrations using the most advanced methods of nonlinear vibrational spectroscopy, including femtosecond two-dimensional infrared spectroscopy. He shows for the first time that the structure of interfacial water undergoes very limited fluctuations on a 300 fs time scale and that the lifetimes of hydrogen bonds with the phospholipid are typically longer than 10 ps. Such properties originate from the steric hindrance of water fluctuations at the interface and the orienting action of strong electric fields from the phospholipid head group dipoles. In an extensive series of additional experiments, the vibrational lifetimes of the different vibrations and the processes of energy dissipation are elucidated in detail.

First published in 2004. Routledge is an imprint of Taylor & Francis, an informa company.