Abstract:
:Electron-electron double resonance (ELDOR) and saturation-recovery spectroscopy employing 14N:15N stearic acid spin-label pairs have been used to study the effects of cholesterol on lateral diffusion and vertical fluctuations in lipid bilayers. The 14N:15N continuous wave electron-electron double resonance (CW ELDOR) theory has been developed using rate equations based on the relaxation model. The collision frequency between 14N-16 doxyl stearate and 15N-16 doxyl stearate, WHex (16:16), is indicative of lateral diffusion of the spin probes, while the collision frequency between 14N-16 doxyl stearate and 15N-5 doxyl stearate, WHex (16:5), provides information on vertical fluctuations of the 14N-16 doxyl stearate spin probe toward the membrane surface. Our results show that: (a) cholesterol decreases the electron spin-lattice relaxation time Tle of 14N-16 doxyl stearate spin label in dimyristoylphosphatidylcholine (DMPC) and egg yolk phosphatidylcholine (egg PC). (b) Cholesterol increases the biomolecular collision frequency WHex (16:16) and decreases WHex (16:5), suggesting that incorporation of cholesterol significantly orders the part of the bilayer that it occupies and disorders the interior region of the bilayer. (c) Alkyl chain unsaturation of the host lipid moderates the effect of cholesterol on both vertical fluctuations and lateral diffusion of 14N-16 doxyl stearate. And (d), there are marked differences in the effects of cholesterol on lateral diffusion and vertical fluctuations between 0-30 mol% and 30-50 mol% of cholesterol that suggest an inhomogeneous distribution of cholesterol in the membrane.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Yin JJ,Feix JB,Hyde JSdoi
10.1016/S0006-3495(87)83296-4subject
Has Abstractpub_date
1987-12-01 00:00:00pages
1031-8issue
6eissn
0006-3495issn
1542-0086pii
S0006-3495(87)83296-4journal_volume
52pub_type
杂志文章abstract::Tip links are thought to gate the mechanically sensitive transduction channels of hair cells, but how they form during development and regeneration remains mysterious. In particular, it is unclear how tip links are strung between stereocilia so that they are oriented parallel to a single axis; why their polarity is un...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2017.08.029
更新日期:2017-10-17 00:00:00
abstract::The x-ray structure analysis of photosystem I (PS I) crystals at 4-A resolution (Schubert et al., 1997, J. Mol. Biol. 272:741-769) has revealed the distances between the three iron-sulfur clusters, labeled F(X), F(1), and F(2), which function on the acceptor side of PS I. There is a general consensus concerning the as...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76599-4
更新日期:2000-01-01 00:00:00
abstract::Recent theoretical work on the cooperative equilibrium binding of myosin subfragment-1-ADP to regulated actin, as influenced by Ca2+, is extended here to the cooperative steady-state ATPase activity of myosin subfragment-1 on regulated actin. Exact solution of the general steady-state problem will require Monte Carlo ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(81)84777-7
更新日期:1981-07-01 00:00:00
abstract::Ceramides have been implicated in the initiation of apoptosis by permeabilizing the mitochondrial outer membrane to small proteins, including cytochrome c. In addition, ceramides were shown to form large metastable channels in planar membranes and liposomes, indicating that these lipids permeabilize membranes directly...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.071977
更新日期:2006-04-01 00:00:00
abstract::Thin filament regulation of contraction is thought to involve the binding of two activating ligands: Ca2+ and strongly bound cross-bridges. The specific cross-bridge states required to promote thin filament activation have not been identified. This study examines the relationship between cross-bridge cycling and thin ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(99)77371-6
更新日期:1999-04-01 00:00:00
abstract::To elucidate effects of electrostatic interactions resulting from surface charges on structures and phase stability of cubic phases of lipid membranes, membranes of 1-monoolein (MO) and dioleoylphosphatidic acid (DOPA) (DOPA/MO membrane) mixtures have been investigated by small-angle x-ray scattering method. As increa...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)75756-6
更新日期:2001-08-01 00:00:00
abstract::Interactions between the graft copolymer poly(L-lysine)-g-poly(ethylene glycol), PLL-g-PEG, and two kinds of surface-supported lipidic systems (supported phospholipid bilayers and supported vesicular layers) were investigated by a combination of microscopic and spectroscopic techniques. It was found that the applicati...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.041780
更新日期:2004-09-01 00:00:00
abstract::Association of transmembrane (TM) helices is facilitated by the close packing of small residues present along the amino-acid sequence. Extensive studies have established the role of such small residue motifs (GxxxG) in the dimerization of Glycophorin A (GpA) and helped to elucidate the association of TM domains in the...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.10.023
更新日期:2010-12-01 00:00:00
abstract::The availability of very high magnetic fields of up to 170,000 gauss made it worthwhile to pursue the search for a critical change in the rate of four enzyme substrate reactions. The four enzymes were ribonuclease, polyphenol oxidase, peroxidase, and aldolase. The experiments showed that, to within +/-3%, no detectabl...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(67)86583-4
更新日期:1967-03-01 00:00:00
abstract::The E5 oncoprotein is the major transforming protein of bovine papillomavirus type 1. This 44-residue transmembrane protein can interact with the platelet-derived growth factor receptor β, leading to ligand-independent activation and cell transformation. For productive interaction, E5 needs to dimerize via a C-termina...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.06.073
更新日期:2010-09-22 00:00:00
abstract::Biological spread cells exist in a perpetually fluctuating state and therefore cannot be described in terms of a unique deterministic system. For modeling approaches to provide novel insight and uncover new mechanisms that drive cell behavior, a framework is required that progresses from traditional deterministic meth...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2018.11.007
更新日期:2018-12-18 00:00:00
abstract::Trains of nerve impulses from the crayfish stretch receptor under steady conditions are found to be extremely regular with a standard deviation of S = 0.7 x 10(-2)tau when tau, the mean interval, is in the 15 to 80 msec range. Such a small fluctuation increases the problems of film recording, accurate measurement of i...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(66)86651-1
更新日期:1966-03-01 00:00:00
abstract::Forces generated by microtubule polymerization and depolymerization are important for the biological functioning of cells. The mean growth velocity, V, under an opposing force, F, has been measured by; Science 278:856-860) for single microtubules growing in vitro, but their analysis of the data suggested that V decrea...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)76002-X
更新日期:2001-01-01 00:00:00
abstract::We have studied the large increase in macroscopic potassium channel current caused by catecholamines in mammalian cardiac cells. An increase in macroscopic K current could result from either an increase in the single-channel current or by an increase in the number of channels that are open. Therefore, we have measured...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(89)82872-3
更新日期:1989-04-01 00:00:00
abstract::The membrane disruption mechanism of pandinin 1 (pin1), an antimicrobial peptide isolated from the venom of the African scorpion, was studied using 31P, 13C, 1H solid-state and multidimensional solution-state NMR spectroscopy. A high-resolution NMR solution structure of pin1 showed that the two distinct alpha-helical ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.070292
更新日期:2005-12-01 00:00:00
abstract::The mathematical model of steady-state iron kinetics in the human presented here extends the use of radioactive tracer observations in the determination of erythron maturative and proliferative behavior. Functions descriptive of that behavior appear explicitly in the model together with functions customarily measured ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(65)86750-9
更新日期:1965-11-01 00:00:00
abstract::A newly developed water-soluble phosphor suitable for measuring oxygen pressure in the blood (Green 2W) was used for noninvasive, in vivo imaging of oxygen distribution in the vascular systems of mice. Oxygen quenches the phosphorescence of Green 2W, measured in the presence of 2% albumin, according to the Stern-volme...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79764-3
更新日期:1996-04-01 00:00:00
abstract::Sarcomere lengths, cell widths, indices of stiffness, and striation pattern uniformity were determined from radially compressed isolated adult cardiac myocytes from the rat. Single cells were bathed in a series of relaxing solutions containing 0-15% concentrations of nonpenetrating long chain polymers PVP-40 and dextr...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(90)82467-X
更新日期:1990-11-01 00:00:00
abstract::We examined the effects of brief current pulses on the pacemaker oscillations of the Purkinje fiber using the model of McAllister , Noble, and Tsien (1975. J. Physiol. [Lond.]. 251:1-57). This model was used to construct phase-response curves for brief electric stimuli to find "black holes," where rhythmic activity of...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(84)84228-9
更新日期:1984-04-01 00:00:00
abstract::The rat connexin40 gap junction channel is permeable to monovalent cations including tetramethylammonium and tetraethylammonium ions. Larger tetraalkyammonium (TAA(+)) ions beginning with tetrabutylammonium (TBA(+)) reduced KCl junctional currents disproportionately. Ionic blockade by tetrapentylammonium (TPeA(+)) and...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)75960-7
更新日期:2001-12-01 00:00:00
abstract::We investigated whether transient step reductions in divalent cations would produce detectable changes in neuronal excitability similar to those reported in the total absence of divalent cations. Using cultured chick dorsal root ganglion cells as a model system, our results indicate that a step reduction in divalent c...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(86)83515-9
更新日期:1986-10-01 00:00:00
abstract::It has been a long belief that release of substances from the cell to the extracellular milieu by exocytosis is completed by diffusion of the substances from secretory vesicles through the fusion pore. Involvement of any mechanical force that may be superposed on the diffusion to enhance the releasing process has not ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(02)75159-X
更新日期:2002-07-01 00:00:00
abstract::The mechanisms by which extracellular electric field stimuli induce the (re)excitation of cardiac cells in various stages of refractoriness are still not well understood. We modeled the interactions between an isolated cardiac cell and imposed extracellular electric fields to determine the mechanisms by which relative...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79692-3
更新日期:1996-03-01 00:00:00
abstract::Ion conduction across the cellular membrane requires the simultaneous opening of activation and inactivation gates of the K+ channel pore. The bacterial KcsA channel has served as a powerful system for dissecting the structural changes that are related to four major functional states associated with K+ gating. Yet, th...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.12.001
更新日期:2017-01-10 00:00:00
abstract::Wiener kernels have been measured for the light growth response of a number of mutants of Phycomyces which show abnormal phototropism (mad mutants). Representative mutants were chosen from the six complementation groups (madA to madF) associated with the light response pathway. One group, madA, associated with the inp...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(75)85881-4
更新日期:1975-10-01 00:00:00
abstract::Exchangeable apolipoproteins are located in the surface of lipoprotein particles and regulate lipid metabolism through direct protein-protein and protein-lipid interactions. These proteins are characterized by the presence of tandem repeats of amphiphatic alpha-helix segments and a high surface activity in monolayers ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.115220
更新日期:2008-03-01 00:00:00
abstract::Glucagon solutions at pH 2.0 were subjected to mechanical agitation at 37 degrees C in the presence of a hydrophobic surface to explore the details of aggregation and fiber formation. High-resolution intermittent-contact atomic force microscopy performed in solution revealed the presence of aggregates after 0.5 h; how...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.077438
更新日期:2006-09-01 00:00:00
abstract::Describing and understanding the biological function of a protein requires a detailed structural and thermodynamic description of the protein's native state ensemble. Obtaining such a description often involves characterizing equilibrium fluctuations that occur beyond the nanosecond timescale. Capturing such fluctuati...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.094409
更新日期:2007-03-01 00:00:00
abstract::Calculations based on the known dimensions of bull spermatozoa show that the scattered light intensity is strongly dependent upon the relative orientation of the particle to the incident beam. The magnitude of this effect of apparently much greater than for other systems where motility has been investigated by dynamic...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(80)85046-6
更新日期:1980-07-01 00:00:00
abstract::Nuclear receptor (NR) ligands occupy a pocket that lies within the core of the NR ligand-binding domain (LBD), and most NR LBDs lack obvious entry/exit routes upon the protein surface. Thus, significant NR conformational rearrangements must accompany ligand binding and release. The precise nature of these processes, h...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.063818
更新日期:2005-09-01 00:00:00