Abstract:
:The distribution of low concentrations of ganglioside GM1 in L-alpha-dipalmitoylphosphatidylcholine (DPPC) and DPPC/cholesterol monolayers supported on mica has been studied using atomic force microscopy (AFM). The monolayers studied correspond to a pure gel phase and a mixture of liquid-expanded (LE) and liquid-condensed (LC) phases for DPPC and to a single homogeneous liquid-ordered phase for 2:1 DPPC/cholesterol. The addition of 2.5-5% GM1 to phase-separated DPPC monolayers resulted in small round ganglioside-rich microdomains in the center and at the edges of the LC domains. Higher amounts of GM1 (10%) give numerous filaments in the center of the LC domains and larger patches at the edges. A gel phase DPPC monolayer containing GM1 showed large domains containing a network of GM1-rich filaments. The addition of GM1 to a liquid-ordered 2:1 DPPC/cholesterol monolayer gives small, round domains that vary in size from 50 to 150 nm for a range of surface pressures. Larger amounts of GM1 lead to coalescence of the small, round domains to give longer filaments that cover 30-40% of the monolayer surface for 10 mol % GM1. The results indicate that biologically relevant GM1 concentrations lead to submicron-sized domains in a cholesterol-rich liquid-ordered phase that is analogous to that found in detergent-insoluble membrane fractions, and are thought to be important in membrane microdomains or rafts. This demonstrates that AFM studies of model monolayers and bilayers provide a powerful method for the direct detection of microdomains that are too small for study with most other techniques.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Yuan C,Johnston LJdoi
10.1016/S0006-3495(00)76516-7subject
Has Abstractpub_date
2000-11-01 00:00:00pages
2768-81issue
5eissn
0006-3495issn
1542-0086pii
S0006-3495(00)76516-7journal_volume
79pub_type
杂志文章abstract::Back-of-the-envelope or rule-of-thumb calculations involving rough estimates of quantities play a central scientific role in developing intuition about the structure and behavior of physical systems, for example in so-called Fermi problems in the physical sciences. Such calculations can be used to powerfully and quant...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.08.040
更新日期:2014-12-02 00:00:00
abstract::It has been a significant challenge to quantitatively study the dynamic intracellular processes in live cells. These studies are essential for a thorough understanding of the underlying mechanisms regulating the signaling pathways and the transitions between cell cycle stages. Our studies of Cdc20, an important mitoti...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.077891
更新日期:2006-07-01 00:00:00
abstract::Spatial patterning of biochemical cues on the micro- and nanometer scale controls numerous cellular processes such as spreading, adhesion, migration, and proliferation. Using force microscopy we show that the lateral spacing of individual integrin receptor-ligand bonds determines the strength of cell adhesion. For spa...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.11.001
更新日期:2010-02-17 00:00:00
abstract::Myosin II is a central mechanoenzyme in a wide range of cellular morphogenic processes. Its cellular localization is dependent not only on signal transduction pathways, but also on mechanical stress. We suggest that this stress-dependent distribution is the result of both the force-dependent binding to actin filaments...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.12.020
更新日期:2012-01-18 00:00:00
abstract::Fibrillar aggregation of the protein ataxin-3 is linked to the inherited neurodegenerative disorder Spinocerebellar ataxia type 3, a member of the polyQ expansion disease family. We previously reported that aggregation and stability of the nonpathological form of ataxin-3, carrying an unexpanded polyQ tract, are modul...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.02.056
更新日期:2011-04-20 00:00:00
abstract::We have developed a novel, spectroscopic technique for high-sensitivity, label-free DNA quantification. We demonstrate that an optical resonance (whispering gallery mode) excited in a micron-sized silica sphere can be used to detect and measure nucleic acids. The surface of the silica sphere is chemically modified wit...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74625-6
更新日期:2003-09-01 00:00:00
abstract::Molecular dynamics simulations in simplified models allow one to study the scaling properties of folding times for many proteins together under a controlled setting. We consider three variants of the Go models with different contact potentials and demonstrate scaling described by power laws and no correlation with the...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74867-X
更新日期:2003-01-01 00:00:00
abstract::Forces applied by intact mucus-propelling cilia were measured for the first time that we know of using a combined atomic force microscopy (AFM) and electrooptic system. The AFM probe was dipped into a field of beating cilia and its time-dependent deflection was recorded as it was struck by the cilia while the electroo...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.094698
更新日期:2007-03-01 00:00:00
abstract::The E462R mutation in the fifth position of the AID (alpha1 subunit interaction domain) region in the I-II linker is known to significantly accelerate voltage-dependent inactivation (VDI) kinetics of the L-type CaV1.2 channel, suggesting that the AID region could participate in a hinged-lid type inactivation mechanism...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.045559
更新日期:2004-11-01 00:00:00
abstract::The goal of this paper is to examine the origins and relative importance of primary and secondary sources of electric and magnetic fields for excitable tissue. It is shown that for axonal and cardiac tissue a comparison of the relative field strength from both primary and secondary sources shows only the latter to be ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(82)84521-9
更新日期:1982-09-01 00:00:00
abstract::mRNAs are involved in complicated supramolecular complexes with human 40S and 80S ribosomes responsible for the protein synthesis. In this work, a derivative of nonaribonucleotide pUUCGUAAAA with nitroxide spin labels attached to the 5'-phosphate and to the C8 atom of the adenosine in sixth position (mRNA analog) was ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2015.10.042
更新日期:2015-12-15 00:00:00
abstract::The fusion peptides of HIV and influenza virus are crucial for viral entry into a host cell. We report the membrane-perturbing and structural properties of fusion peptides from the HA fusion protein of influenza virus and the gp41 fusion protein of HIV. Our goals were to determine: 1), how fusion peptides alter struct...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.063032
更新日期:2005-11-01 00:00:00
abstract::Förster resonance energy transfer (FRET) has become an important tool for analyzing different aspects of interactions among biological macromolecules in their native environments. FRET analysis has also been successfully applied to study the spatiotemporal regulation of various cellular processes using genetically enc...
journal_title:Biophysical journal
pub_type: 杂志文章,评审
doi:10.1016/j.bpj.2012.09.031
更新日期:2012-11-07 00:00:00
abstract::Interpretation of fluorescence anisotropy decay for the case of restricted rotational diffusion often requires a model. To investigate the extent of model dependence, two models are compared: a strict cone model, in which a fluorescent probe wobbles uniformly within a cone, and a Gaussian model, where the stationary d...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(82)84692-4
更新日期:1982-02-01 00:00:00
abstract::Leukocyte capture and rolling on the vascular endothelium is mediated principally by the selectin family of cell adhesion receptors. In a parallel plate flow chamber, neutrophil rolling on purified selectins or a selectin-ligand substrate was resolved by high speed videomicroscopy as a series of ratchet-like steps wit...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(99)77169-9
更新日期:1999-12-01 00:00:00
abstract::We report the crystal structure of a bromide-bound form of the D85S mutant of bacteriorhodopsin, bR(D85S), a protein that uses light energy rather than ATP to pump halide ions across the cell membrane. Comparison of the structure of the halide-bound and halide-free states reveals that both displacements of individual ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74490-7
更新日期:2003-07-01 00:00:00
abstract::The ability to discriminate between different cations efficiently is essential for the proper physiological functioning of many membrane transport proteins. One obvious mechanism of ion selectivity is when a binding site is structurally constrained by the protein architecture and its geometry is precisely adapted to f...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.03.038
更新日期:2010-06-16 00:00:00
abstract::Enterococcus hirae V1-ATPase is a molecular motor composed of the A3B3 hexamer ring and the central stalk. In association with ATP hydrolysis, three catalytic AB pairs in the A3B3 ring undergo conformational changes, which lead to a 120° rotation of the central stalk. To understand how the conformational changes of th...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2017.01.029
更新日期:2017-03-14 00:00:00
abstract::The centromeric histone H3 variant centromeric protein A (CENP-A), whose sequence is the least conserved among all histone variants, is responsible for specifying the location of the centromere. Here, we present a comprehensive study of CENP-A nucleosome arrays by cryo-electron tomography. We see that CENP-A arrays ha...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.01.005
更新日期:2014-02-18 00:00:00
abstract::Solid phase amplification (SPA), a new method to amplify DNA, is characterized by the use of surface-bound primers. This limits the amplification to two-dimensional surfaces and therefore allows the easy parallelization of DNA amplification in a single system. SPA leads to the formation of small but dense DNA brushes,...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.051904
更新日期:2005-07-01 00:00:00
abstract::Single-molecule studies allow the study of subtle activity differences due to local folding in proteins, but are time consuming and difficult because only a few molecules are observed in one experiment. We developed an assay where we can simultaneously measure the activity of hundreds of individual molecules. The assa...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.055053
更新日期:2005-06-01 00:00:00
abstract::Outside-out patches of enzymatically dissociated adult and denervated mouse muscle fibers were superfused repetitively by pulses of acetylcholine (ACh) containing solution. Up to 300 channels opened simultaneously 300 microseconds after the beginning of a 1,000 microM ACh pulse corresponding to a peak current i of alm...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(91)82138-5
更新日期:1991-11-01 00:00:00
abstract::The Ciona intestinalis voltage-sensitive phosphatase (Ci-VSP) represents the first discovered member of enzymes regulated by a voltage-sensor domain (VSD) related to the VSD found in voltage-gated ion channels. Although the VSD operation in Ci-VSP exhibits original voltage dependence and kinetics compared to ion chann...
journal_title:Biophysical journal
pub_type: 信件
doi:10.1016/j.bpj.2012.06.030
更新日期:2012-08-08 00:00:00
abstract::The orientational ordering of beta-carotene and crocetin embedded in lamellar model membranes has been investigated by angle-resolved resonance Raman scattering at a temperature well above the phase transition of the lipid chains. It is shown that the ordering of the carotenoids is dependent on the chemical compositio...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(84)84269-1
更新日期:1984-06-01 00:00:00
abstract::We present a new approach to probing single-particle dynamics that uses dynamic light scattering from a localized region. By scattering a focused laser beam from a micron-size particle, we measure its spatial fluctuations via the temporal autocorrelation of the scattered intensity. We demonstrate the applicability of ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)77866-X
更新日期:1998-03-01 00:00:00
abstract::We describe simulations of absorption difference spectra in strongly coupled photosynthetic antennas. In the presence of large resonance couplings, distinctive features arise from excited-state absorption transitions between one- and two-exciton levels. We first outline the theory for the heterodimer and for the gener...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(97)78644-2
更新日期:1997-01-01 00:00:00
abstract::The cellular cytoplasm is a complex, heterogeneous environment (both spatially and temporally) that exhibits viscoelastic behavior. To further develop our quantitative insight into cellular transport, we analyze data sets of mRNA molecules fluorescently labeled with MS2-GFP tracked in real time in live Escherichia col...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.11.3208
更新日期:2017-02-07 00:00:00
abstract::The excitation of the squid giant axon that had been perfused intra- and extracellularly with solutions containing a high concentration of glycerol could be observed below 0 degree C. The action potential could be elicited at normal strengths of electrical stimuli. The time-course of the action potential was slowed, w...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(81)84785-6
更新日期:1981-07-01 00:00:00
abstract::Analyses of receptor-ligand interactions are important to the understanding of cellular adhesion. Traditional methods of measuring the three-dimensional (3D) dissociation constant (Kd) require at least one of the molecular species in solution and hence cannot be directly applied to the case of cell adhesion. We descri...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)77807-5
更新日期:1998-01-01 00:00:00
abstract::Sedimentation velocity analytical ultracentrifugation is an important tool in the characterization of macromolecules and nanoparticles in solution. The sedimentation coefficient distribution c(s) of Lamm equation solutions is based on the approximation of a single, weight-average frictional coefficient of all particle...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.081372
更新日期:2006-06-15 00:00:00