Monte Carlo Studies of the Effects of Protein, Cholesterol and Curvature on Lipid Order Parameters
Author: Sheau-Lin Sharon Cherng
Publisher:
Published: 1978
Total Pages: 90
ISBN-13:
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Author: Sheau-Lin Sharon Cherng
Publisher:
Published: 1978
Total Pages: 90
ISBN-13:
DOWNLOAD EBOOKAuthor: Frédérick Jean-Marie De Meyer
Publisher:
Published: 2010
Total Pages: 304
ISBN-13:
DOWNLOAD EBOOKIn this work we use molecular simulations to investigate how cholesterol affects membrane-mediated protein-protein interactions. We consider a typical hydrated biological model membrane containing saturated phospholipids (for example, dimyris- toylphosphatidylcholine or DMPC), cholesterol, and trans-membrane proteins. We introduce a model in which the different molecules are coarse-grained, retaining their hydrophobic and hydrophilic properties together with their main structure and flexi- bility. The system is studied using a hybrid Monte-Carlo dissipative particle dynamics method. First we study lipid-mediated protein-protein interactions in a pure hydrated sat- urated phospholipid bilayer. The potential of mean force between the proteins show that hydrophobic forces drive long-range lipid-mediated protein-protein interactions and that the nature of these interactions depends on the length of the protein hy- drophobic segment, on the three-dimensional structure of the protein and on the properties of the lipid bilayer. The concept of hydrophilic shielding is introduced to gain insight into the nature of the computed potentials of mean force. To study the effect of cholesterol on the properties of a membrane, we extend our model to cholesterol. Structural and mechanical properties of the hydrated bi- layer containing a saturated lipid and cholesterol are studied at various temperatures and cholesterol concentrations. The properties studied are the area per lipid, con- densation, bilayer thickness, tail order parameters, bending modulus, and area com- pressibility. The model quantitatively reproduces most of the experimental effects of cholesterol on these properties and reproduces the main features of the experi- mental temperature-composition phase diagram. Based on the changes in structural properties a temperature-composition structure diagram is proposed, which is com- pared with the experimental phase and structure diagrams. The lateral organization of cholesterol in the bilayer is also discussed. In a second part, modifications of the cholesterol model are made to allow a better understanding of the cholesterol condensation effect. This condensation effect is further discussed in relation to the DMPC-cholesterol phase behavior. Finally, the effect of cholesterol on lipid-mediated protein-protein interactions is investigated. This is done in accordance with the results concerning the effect of cholesterol on the phase behavior of lipid bilayers. The calculations of the potential of mean force between proteins and protein clusters show that the addition of choles- terol gradually reduces repulsive lipid-mediated interactions between certain proteins. At a given cholesterol concentration, the interactions even become attractive. Hence, cholesterol significantly promotes protein aggregation. The role of protein-induced dynamical cholesterol-enriched and cholesterol-depleted shells in these effects is dis- cussed in detail.
Author: Kenny B. Lipkowitz
Publisher: John Wiley & Sons
Published: 2009-09-22
Total Pages: 482
ISBN-13: 0470126094
DOWNLOAD EBOOKFührende Experten auf dem Gebiet der Computer-Chemie präsentieren in dem fünften Band der erfolgreichen Reihe 'Reviews in Computational Chemistry' die neuesten Entwicklungen. Um den interessierten Chemiker auf dem aktuellen Stand zu halten, ist der Reihe im Anhang eine Liste mit der Software zum Thema beigefügt
Author:
Publisher: Academic Press
Published: 2015-06-08
Total Pages: 393
ISBN-13: 0128033274
DOWNLOAD EBOOKCurrent Topics in Membranes is targeted toward scientists and researchers in biochemistry and molecular and cellular biology, providing the necessary membrane research to assist them in discovering the current state of a particular field and in learning where that field is heading. This volume offers an up to date presentation of current knowledge in the field of Lipid Domains. Written by leading experts Contains original material, both textual and illustrative, that should become a very relevant reference material The material is presented in a very comprehensive manner Both researchers in the field and general readers should find relevant and up-to-date information
Author: Wade H. Shafer
Publisher: Springer Science & Business Media
Published: 2012-12-06
Total Pages: 306
ISBN-13: 1468436201
DOWNLOAD EBOOKMasters Theses in the Pure and Applied Sciences was first conceived, published, and dis seminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the ac tivity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volume were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 23 (thesis year 1978) a total of 10,148 theses titles from 27 Canadian and 220 United States universities. We are sure that this broader base for theses titles reported will greatly enhance the value of this important annual reference work. While Volume 23 reports these submitted in 1978, on occasion, certain universities do report theses submitted in previous years but not reported at the time.
Author: Yvonne Nga Fong Yuan
Publisher:
Published: 2004
Total Pages: 0
ISBN-13:
DOWNLOAD EBOOKThe effects of cholesterol on the phase behaviour of lipid bilayers composed of Dilauroyl phosphatidylcholine (DLPC) and Dipalmitoyl phosphatidylcholine (DPPC) are investigated. Metropolis Monte Carlo simulations are performed on a 2-dimensional multi-state lattice model, which is a direct extension of the Pink model originally proposed to describe the main phase transition of single-component lipid bilayers. The binary mixture containing DLPC and DPPC was chosen because it is assumed to mimic lipid systems used in experimental investigations of the properties of rafts. Our calculations proceed as follows: (i) Simulations were first performed on single-component phosphatidylcholine (PC) bilayers with chain length ranging from 12 to 22. Our results were found to be in excellent agreement with previous simulations performed by different groups with the same parameter sets. (ii) Simulations on DLPC/cholesterol and DPPC/cholesterol bilayers were then performed, which were found to agree with experimental data from differential scanning calorimetry (DSC) and deuterium nuclear magnetic resonance (2H-NMR). A liquid-ordered (lo) phase which displays characteristics that are consistent with experimental observations is obtained from our model. Moreover, we found that formation of domains of different sizes can be induced by varying the interaction between the kink state and cholesterol in our model. (iii) Simulations on the binary DLPC/DPPC bilayers in the absence of cholesterol were next performed and reasonable agreement of our theoretical phase diagram with experimentally determined phase diagram from DSC and Fourier Transform Infrared (FTIR) experiments was found. (iv) Finally, simulations of DLPC/DPPC/cholesterol bilayers were performed, in conjunction with an exploration of the parameter space of the interaction between cholesterol and different lipid conformational states. We found that different parameter sets result in formation of domains of different size and component concentration. Two sets of parameters were chosen for which the system contains lo domains at physiological temperature, and at the same time exhibits a molecular order parameter profile that best resembles those from experimental FTIR data.
Author: Robert Brasseur
Publisher: CRC Press
Published: 2019-07-18
Total Pages: 444
ISBN-13: 1000697665
DOWNLOAD EBOOKFirst published in 1990, the goal of these two volumes is to help fill the gap between theory and experiment in membrane science. Those involved with biochemistry, biophysics, pharmacology, and biology will find these volumes interesting and informative.
Author: R. Lipowsky
Publisher: Elsevier
Published: 1995-06-15
Total Pages: 537
ISBN-13: 0080541917
DOWNLOAD EBOOKThe first volume of the Handbook deals with the amazing world of biomembranes and lipid bilayers. Part A describes all aspects related to the morphology of these membranes, beginning with the complex architecture of biomembranes, continues with a description of the bizarre morphology of lipid bilayers and concludes with technological applications of these membranes. The first two chapters deal with biomembranes, providing an introduction to the membranes of eucaryotes and a description of the evolution of membranes. The following chapters are concerned with different aspects of lipids including the physical properties of model membranes composed of lipid-protein mixtures, lateralphase separation of lipids and proteins and measurement of lipid-protein bilayer diffusion. Other chapters deal with the flexibility of fluid bilayers, the closure of bilayers into vesicles which attain a large variety of different shapes, and applications of lipid vesicles and liposomes. Part B covers membrane adhesion, membrane fusion and the interaction of biomembranes withpolymer networks such as the cytoskeleton. The first two chapters of this part discuss the generic interactions of membranes from the conceptual point of view. The following two chapters summarize the experimental work on two different bilayer systems. The next chapter deals with the process ofcontact formation, focal bounding and macroscopic contacts between cells. The cytoskeleton within eucaryotic cells consists of a network of relatively stiff filaments of which three different types of filaments have been identified. As explained in the next chapter much has been recently learned aboutthe interaction of these filaments with the cell membrane. The final two chapters deal with membrane fusion.
Author: Thomas J. McIntosh
Publisher: Humana
Published: 2007-07-06
Total Pages: 326
ISBN-13: 9781588297297
DOWNLOAD EBOOKThere are many unanswered questions concerning the composition, structure, and dynamics of lateral microdomains (rafts) in biological membranes. Thus, sophisticated techniques have been used to study intact cell membranes as well as model systems composed of specific lipids and proteins thought to be in rafts. Using biochemical, biophysical, and computational methods, "Lipid Rafts" provides the most up-to-date information on the subject.
Author:
Publisher:
Published: 1998
Total Pages: 1646
ISBN-13:
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