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Cholesterol in Membrane Models

Author : Leonard X. Finegold

Publisher : CRC Press

Page : 298 pages

File Size : 43,27 MB

Release : 1992-12-15

Category : Science

ISBN : 9780849342073

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Book Description

Cholesterol in Membrane Models provides the most recent summary available of basic molecular models and experiments in models of biological membranes. The book introduces the cell biology of cholesterol and covers the modeling of cholesterol in model membranes by the mean field and Monte Carlo theoretical methods. The experimental movement of cholesterol into model membranes and phase diagrams of cholesterol in these membranes by nuclear magnetic resonance and by thermal techniques using different lipid chain lengths are discussed. Light and electron microscopy that explore the spatial distribution of cholesterol in the model membrane are covered. The book also examines the use of infrared/Raman and neutron spectroscopy. Cholesterol in Membrane Models is an excellent learning resource, research tool, and reference for a wide range of experimental and theoretical scientists, including cellular biologists, biophysicists, biochemists, and molecular modelers.





An Introduction to Biological Membranes

Author : William Stillwell

Publisher : Newnes

Page : 379 pages

File Size : 26,65 MB

Release : 2013-04-20

Category : Science

ISBN : 0080931286

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Book Description

An Introduction to Biological Membranes: From Bilayers to Rafts covers many aspects of membrane structure/function that bridges membrane biophysics and cell biology. Offering cohesive, foundational information, this publication is valuable for advanced undergraduate students, graduate students and membranologists who seek a broad overview of membrane science. Brings together different facets of membrane research in a universally understandable manner Emphasis on the historical development of the field Topics include membrane sugars, membrane models, membrane isolation methods, and membrane transport



Lipid Bilayer Thickness Determines Cholesterol's Location in Model Membranes

Author :

Publisher :

Page : 12 pages

File Size : 38,67 MB

Release : 2016

Category :

ISBN :

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Book Description

Cholesterol is an essential biomolecule of animal cell membranes, and an important precursor for the biosynthesis of certain hormones and vitamins. It is also thought to play a key role in cell signaling processes associated with functional plasma membrane microdomains (domains enriched in cholesterol), commonly referred to as rafts. In all of these diverse biological phenomena, the transverse location of cholesterol in the membrane is almost certainly an important structural feature. Using a combination of neutron scattering and solid-state 2H NMR, we have determined the location and orientation of cholesterol in phosphatidylcholine (PC) model membranes having fatty acids of different lengths and degrees of unsaturation. The data establish that cholesterol reorients rapidly about the bilayer normal in all the membranes studied, but is tilted and forced to span the bilayer midplane in the very thin bilayers. The possibility that cholesterol lies flat in the middle of bilayers, including those made from PC lipids containing polyunsaturated fatty acids (PUFAs), is ruled out. Finally, these results support the notion that hydrophobic thickness is the primary determinant of cholesterol's location in membranes.



The Plasma Membrane

Author : B. D. Gomperts

Publisher :

Page : 244 pages

File Size : 20,54 MB

Release : 1977

Category : Science

ISBN :

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Cholesterol Binding and Cholesterol Transport Proteins:

Author : J. Robin Harris

Publisher : Springer Science & Business Media

Page : 641 pages

File Size : 46,84 MB

Release : 2010-03-10

Category : Science

ISBN : 9048186226

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Book Description

Knowledge of cholesterol and its interaction with protein molecules is of fundamental importance in both animal and human biology. This book contains 22 chapters, dealing in depth with structural and functional aspects of the currently known and extremely diverse unrelated families of cholesterol-binding and cholesterol transport proteins. By drawing together this range of topics the Editor has attempted to correlate this broad field of study for the first time. Technical aspects are given considerable emphasis, particularly in relation cholesterol reporter molecules and to the isolation and study of membrane cholesterol- and sphingomyelin-rich "raft" domains. Cell biological, biochemical and clinical topics are included in this book, which serve to emphasize the acknowledged and important benefits to be gained from the study of cholesterol and cholesterol-binding proteins within the biomedical sciences and the involvement of cholesterol in several clinical disorders. It is hoped that by presenting this topic in this integrated manner that an appreciation of the fact that there is much more that needs to be taken into account, studied and understood than the widely discussed "bad and good cholesterol" associated, respectively, with the low- and high-density lipoproteins, LDL and HDL.



The Membranes of Cells

Author : Philip Yeagle

Publisher :

Page : 376 pages

File Size : 42,46 MB

Release : 1993

Category : Medical

ISBN :

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Book Description

In this new edition of The Membranes of Cells, all of the chapters have been updated, some have been completely rewritten, and a new chapter on receptors has been added. The book has been designed to provide both the student and researcher with a synthesis of information from a number of scientific disciplines to create a comprehensive view of the structure and function of the membranes of cells. The topics are treated in sufficient depth to provide an entry point to the more detailed literature needed by the researcher. Key Features * Introduces biologists to membrane structure and physical chemistry * Introduces biophysicists to biological membrane function * Provides a comprehensive view of cell membranes to students, either as a necessary background for other specialized disciplines or as an entry into the field of biological membrane research * Clarifies ambiguities in the field



Structure and Dynamics of Membranes

Author : R. Lipowsky

Publisher : Elsevier

Page : 537 pages

File Size : 35,12 MB

Release : 1995-06-15

Category : Technology & Engineering

ISBN : 0080541917

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Book Description

The 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.





Effect of Cholesterol Content on Lipid Microdomains in Model Membranes and Cells

Author : Su-In Yoon

Publisher :

Page : 158 pages

File Size : 42,77 MB

Release : 2007

Category : Sterols

ISBN : 9780549081500

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Book Description

Much experimental and theoretical evidence suggests small variations in the mole fraction of sterol can produce significant changes in the lateral organization, which could play a key role in the modulation of membrane function. The initial rate of sterol oxidation in multi-component systems composed of dehydroergosterol(DHE)/1-palmitoyl-2-oleoyl-L-alpha-phosphatidylcholine(POPC)/porcine brain sphingomyelins(pSPMs) is found to change with cholesterol content in an alternating manner, showing local maxima at critical mole fractions (e.g., 20.0, 25.0, 33.3 and 40.0 mol% sterol) predicted for maximal superlattice formation. Thus, this result indicates that the initial rate of sterol oxidation is governed by the extent of cholesterol superlattice and supports the existence of superlattice in multi-component model membranes. In the same system, the initial rate of sterol oxidation was measured in the presence of antioxidants. Lipoic acid and ascorbic acid do not disturb the original membrane lateral organization in spite of being able to reduce sterol oxidation rate. Next, I examined whether superlattice is related to lipid rafts observed in cells and how cholesterol content would affect lipid raft properties and protein behaviors related to lipid rafts. I found the majority of opioid receptors are localized in lipid rafts isolated from rat brain, human placenta, Chinese hamster ovary cells overexpressing FLAG tagged human kappa receptors (FLAG-hKOR) and NG108-15 neuroblastoma x glioma hybrid cells using a non-detergent method. The cholesterol reduction by 2% MCD treatment (∼48%) caused the change in cell shape from spindle to spherical, shift of lipid rafts, caveolin-1 and FLAG-hKOR to higher density fractions and an increase in (-)(trans)-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidiny) cyclohexyl]benzeneacetamide (U50,488H) induced [35S]guanosine 5-(gamma-thio)triphosphate binding. Cholesterol replenishment reversed all the MCD effects. Lipid rafts isolated from multi-component model membranes and from CHO cells also display an alternating variation in raft density with the cholesterol content in original membranes or cells. This biphasic change was shown to be related to protein/lipid ratio and membrane packing in lipid rafts isolated from cells. In addition, the raft density reaches local maxima at critical sterol mole fractions for maximal superlattice formation in model membranes. This new finding suggests that lipid rafts and sterol superlattices may be related.