Why pancreatic islets burst but single beta cells do not. The heterogeneity hypothesis.

abstract：:The recently developed method of site-directed Fourier transform infrared dichroism for obtaining orientational constraints of oriented polymers is applied here to the transmembrane domain of the vpu protein from the human immunodeficiency virus type 1 (HIV-1). The infrared spectra of the 31-residue-long vpu peptide r...

journal_title：Biophysical journal

authors： Kukol A,Arkin IT

更新日期：1999-09-01 00:00:00

abstract：:The temperature dependence of drug blockade of a calcium-dependent potassium channel K(Ca) has been studied in cultured CA1 hippocampal neurons. Channel openings from a 70-pS K+ channel were recorded when inside-out patches were exposed to a bath solution containing 140 mM K+ and 0.2 mM Ca2+. The mean open times of ch...

journal_title：Biophysical journal

authors： McLarnon JG,Wang XP

更新日期：1991-11-01 00:00:00

abstract：:Transmissible spongiform encephalopathies are neurodegenerative diseases characterized by the accumulation of an abnormal isoform of the prion protein PrP(Sc). Its fragment 106-126 has been reported to maintain most of the pathological features of PrP(Sc), and a role in neurodegeneration has been proposed based on the...

journal_title：Biophysical journal

authors： Henriques ST,Pattenden LK,Aguilar MI,Castanho MA

更新日期：2008-08-01 00:00:00

abstract：:We have chemically modified a fraction of the monomers in actin filaments, and then measured the effects on the functional interaction of myosin with unmodified monomers within the same filament. Two modifications were used: (a) covalent attachment of various amounts of myosin subfragment-1 (S1) with the bifunctional ...

journal_title：Biophysical journal

authors： Prochniewicz E,Katayama E,Yanagida T,Thomas DD

更新日期：1993-07-01 00:00:00

abstract：:Recent measurements have demonstrated enzyme activity at hydrations as low as 3%. This raises the question of whether hydration-induced enzyme flexibility is important for activity. Here, to address this, picosecond dynamic neutron scattering experiments are performed on pig liver esterase powders at 0%, 3%, 12%, and ...

journal_title：Biophysical journal

authors： Kurkal V,Daniel RM,Finney JL,Tehei M,Dunn RV,Smith JC

更新日期：2005-08-01 00:00:00

abstract：:Monolayers of a functional pulmonary surfactant (PS) can reach very low surface tensions well below their equilibrium value. The mechanism by which PS monolayers reach such low surface tensions and maintain film stability remains unknown. As shown previously by fluorescence microscopy, phospholipid phase transition an...

journal_title：Biophysical journal

authors： Zuo YY,Keating E,Zhao L,Tadayyon SM,Veldhuizen RA,Petersen NO,Possmayer F

更新日期：2008-05-01 00:00:00

abstract：:This paper describes an analysis of microscopic models for the coupling between ion flow and rotation of bacterial flagella. In model I it is assumed that intersecting half-channels exist on the rotor and the stator and that the driving ion is constrained to move together with the intersection site. Model II is based ...

journal_title：Biophysical journal

authors： Läuger P

更新日期：1988-01-01 00:00:00

abstract：:High-affinity and cooperative binding of two Ca(2+) per ATPase (SERCA) occurs within the membrane-bound region of the enzyme. Direct measurements of binding at various Ca(2+) concentrations demonstrate that site-directed mutations within this region interfere selectively with Ca(2+) occupancy of either one or both bin...

journal_title：Biophysical journal

authors： Inesi G,Zhang Z,Lewis D

更新日期：2002-11-01 00:00:00

abstract：:The coat protein of tobacco mosaic virus is known to form three different classes of aggregate, depending on environmental conditions, namely helical, disk, and A-protein. Among the disk aggregates, there are four-layer, six-layer, and long stacks, which can be obtained by varying the ionic strength and temperature co...

journal_title：Biophysical journal

authors： Díaz-Avalos R,Caspar DL

更新日期：1998-01-01 00:00:00

abstract：:Coarse-grained (CG) models of biomolecules have recently attracted considerable interest because they enable the simulation of complex biological systems on length-scales and timescales that are inaccessible for atomistic molecular dynamics simulation. A CG model is defined by a map that transforms an atomically detai...

journal_title：Biophysical journal

authors： Zhang Z,Lu L,Noid WG,Krishna V,Pfaendtner J,Voth GA

更新日期：2008-12-01 00:00:00

abstract：:The outer membrane porin OmpF from Escherichia coli has been reconstituted into lipid bilayers of defined composition, and fluorescence spectroscopy is used to characterize its interaction with the surrounding lipid. OmpF is a trimer within the membrane. It contains two Trp residues per monomer, Trp(214) at the lipid-...

journal_title：Biophysical journal

authors： O'Keeffe AH,East JM,Lee AG

更新日期：2000-10-01 00:00:00

abstract：:Identifying the basic module of enzymatic amplification as an irreversible cycle of messenger activation/deactivation by a "push-pull" pair of opposing enzymes, we analyze it in terms of gain, bandwidth, noise, and power consumption. The enzymatic signal transduction cascade is viewed as an information channel, the de...

journal_title：Biophysical journal

authors： Detwiler PB,Ramanathan S,Sengupta A,Shraiman BI

更新日期：2000-12-01 00:00:00

abstract：:The Mie theory of scattering is used to provide new information on how changes in particle volume, with no change in dry weight, should influence light scattering for various scattering angles and particle sizes. Many biological cells (e.g., algal cells, erythrocytes) and large subcellular structures (e.g., chloroplas...

journal_title：Biophysical journal

authors： Latimer P,Pyle BE

更新日期：1972-07-01 00:00:00

abstract：:Conventional equations for enzyme kinetics are based on mass-action laws, that may fail in low-dimensional and disordered media such as biological membranes. We present Monte Carlo simulations of an isolated Michaelis-Menten enzyme reaction on two-dimensional lattices with varying obstacle densities, as models of biol...

journal_title：Biophysical journal

authors： Berry H

更新日期：2002-10-01 00:00:00

abstract：:An equation of state for lipid monolayers at the air-water interface is presented, which takes into account the effects of the conformation and the number and position of double bonds of the hydrocarbon chains. The total Hamiltonian of the monolayer is assumed to consist of three terms. Two of them are calculated exac...

journal_title：Biophysical journal

authors： Feng SS,MacDonald RC

更新日期：1995-08-01 00:00:00

abstract：:Despite growing interest in light-driven ion pumps for use in optogenetics, current estimates of their transport rates span two orders of magnitude due to challenges in measuring slow transport processes and determining protein concentration and/or orientation in membranes in vitro. In this study, we report, to our kn...

journal_title：Biophysical journal

authors： Feroz H,Ferlez B,Lefoulon C,Ren T,Baker CS,Gajewski JP,Lugar DJ,Gaudana SB,Butler PJ,Hühn J,Lamping M,Parak WJ,Hibberd JM,Kerfeld CA,Smirnoff N,Blatt MR,Golbeck JH,Kumar M

更新日期：2018-07-17 00:00:00

abstract：:The engulfment function of macrophages relies on complex molecular interactions involving both lipids and proteins. In particular, the clearance of apoptotic bodies (efferocytosis) is enabled by externalization on the cell target of phosphatidylserine lipids, which activate receptors on macrophages, suggesting that (l...

journal_title：Biophysical journal

authors： Justice MJ,Petrusca DN,Rogozea AL,Williams JA,Schweitzer KS,Petrache I,Wassall SR,Petrache HI

更新日期：2014-02-04 00:00:00

abstract：:An analysis of four 1-ns molecular dynamics trajectories for two different 15-bp oligonucleotides is presented. Our aim is to show which groups of atoms can be treated as rigid bodies within a bead representation of DNA, independently of the base sequence and for any conformations belonging to the A/B family. Five mod...

journal_title：Biophysical journal

authors： Bruant N,Flatters D,Lavery R,Genest D

更新日期：1999-11-01 00:00:00

abstract：:The molecular weight of single-stranded DNA from the slime mold Physarum polycephalum has been determined by alkaline gradient centrifugation. The average molecular weight during DNA synthesis ( approximately 1.5 x 10(7) D) is less than that observed in nonsynthetic periods ( approximately 4 x 10(7) D). On the basis o...

journal_title：Biophysical journal

authors： McGrath RA,Williams RW

更新日期：1967-05-01 00:00:00

abstract：:This study presents what is, to our knowledge, a novel technique by means of which the ratio of the single gating charges of voltage-gated rat brain IIA (rBIIA) sodium and Shaker potassium ion channels was estimated. In the experiment, multiple tandems of enhanced green fluorescent protein were constructed and inserte...

journal_title：Biophysical journal

authors： Gamal El-Din TM,Grögler D,Lehmann C,Heldstab H,Greeff NG

更新日期：2008-08-01 00:00:00

abstract：:Bovine brain phosphatidylserine (BBPS) vesicles were prepared with traces of dioleoylglycerol (18:1, 18:1 DAG) or hexadecane (HD) to determine the influence of changes in headgroup or acyl chain packing on divalent cation-induced lipid mixing rates. A stopped-flow apparatus was used to combine vesicles with 3 mM Ca2+ ...

journal_title：Biophysical journal

authors： Walter A,Yeagle PL,Siegel DP

更新日期：1994-02-01 00:00:00

abstract：:Supercoiled DNA polymer models for which the torsional energy depends on the total twist of molecules (Tw) are a priori well suited for thermodynamic analysis of long molecules. So far, nevertheless, the exact determination of Tw in these models has been based on a computation of the writhe of the molecules (Wr) by ex...

journal_title：Biophysical journal

authors： Lepage T,Képès F,Junier I

更新日期：2015-07-07 00:00:00

abstract：:Photosynthetic organisms drive their metabolism by converting light energy into an electrochemical gradient with high efficiency. This conversion depends on the diffusion of quinones within the membrane. In purple photosynthetic bacteria, quinones reduced by the reaction center (RC) diffuse to the cytochrome bc(1) com...

journal_title：Biophysical journal

authors： Scheuring S,Sturgis JN

更新日期：2006-11-15 00:00:00

abstract：:Label-free imaging techniques such as differential interference contrast (DIC) allow the observation of cells and large subcellular structures in their native, unperturbed states with minimal exposure to light. The development of robust computational image-analysis routines is vital to quantitative label-free imaging....

journal_title：Biophysical journal

authors： Chaphalkar AR,Jawale YK,Khatri D,Athale CA

更新日期：2021-01-11 00:00:00

abstract：:It is widely assumed that the decay of fluorescence in photosynthetic systems can be described as a sum of exponential components and that the amplitude of each component is directly related to the absorption cross-section of the antenna pigments coupled to the fluorescing species. We present exact calculations of exc...

journal_title：Biophysical journal

authors： Jean JM,Chan CK,Fleming GR,Owens TG

更新日期：1989-12-01 00:00:00

abstract：:Molecular dynamics simulations supplement single-molecule pulling experiments by providing the possibility of examining the full free energy landscape using many coordinates. Here, we use an all-atom structure-based model to study the force and temperature dependence of the unfolding of the protein filamin by applying...

journal_title：Biophysical journal

authors： Sun L,Noel JK,Sulkowska JI,Levine H,Onuchic JN

更新日期：2014-12-16 00:00:00

abstract：:Five highly homologous epidermal growth factor receptor ligands were studied by mass spectral analysis, hydrogen/deuterium (H/D) exchange via attenuated total reflectance Fourier transform-infrared spectroscopy, and two-dimensional correlation analysis. These studies were performed to determine the order of events dur...

journal_title：Biophysical journal

authors： Iloro I,Narváez D,Guillén N,Camacho CM,Guillén L,Cora E,Pastrana-Ríos B

更新日期：2008-05-15 00:00:00

abstract：:A partially depolarized squid axon membrane is assumed to have a quasi-steady state negative resistance, the membrane potential is clamped at one point, and a distribution of potential along the axon is obtained from the cable equation. Nominal experimental values of -2 ohm cm(2) for the membrane and 6 ohm cm(2) for t...

journal_title：Biophysical journal

authors： COLE KS

更新日期：1961-05-01 00:00:00

abstract：:Fluo-3 is an unusual tetracarboxylate Ca2+ indicator. For recent lots supplied by Molecular Probes Inc. (Eugene, OR), FMAX, the fluorescence intensity of the indicator in its Ca(2+)-bound form, is approximately 200 times that of FMIN, the fluorescence intensity of the indicator in its Ca(2+)-free form. (For earlier lo...

journal_title：Biophysical journal

authors： Harkins AB,Kurebayashi N,Baylor SM

更新日期：1993-08-01 00:00:00

abstract：:This study aims to define the role of E-cadherin (Ecad) engagement in cell-cell contact during membrane-cortex interaction. As a tool, we used a hydrodynamic membrane tube extrusion technique to characterize the mechanical interaction between the plasma membrane and the underlying cortical cytoskeleton. Cells were anc...

journal_title：Biophysical journal

authors： Tabdanov E,Borghi N,Brochard-Wyart F,Dufour S,Thiery JP

更新日期：2009-03-18 00:00:00