Asymmetric modulation and blockade of the delayed rectifier in squid giant axons by divalent cations.

abstract：:THE THEORY OF ELECTROTONUS, WHICH HAS BEEN WELL DEVELOPED FOR SMALL CYLINDERS, IS EXTENDED: the fundamental potential equations for a membrane of arbitrary shape are derived, and solutions are found for cylindrical and spherical geometries. If two purely conductive media are separated by a resistance-capacitance membr...

journal_title：Biophysical journal

authors： Hellerstein D

更新日期：1968-03-01 00:00:00

abstract：:The regulated ability of integrin alphaIIbbeta3 to bind fibrinogen plays a crucial role in platelet aggregation and hemostasis. We have developed a model system based on laser tweezers, enabling us to measure specific rupture forces needed to separate single receptor-ligand complexes. First of all, we performed a thor...

journal_title：Biophysical journal

authors： Litvinov RI,Bennett JS,Weisel JW,Shuman H

更新日期：2005-10-01 00:00:00

abstract：:Extracellular vesicles (EVs) are proposed to play important roles in intercellular communication. Two classes of EVs can be distinguished based on their intracellular origin. Exosomes are generated within endosomes and released when these fuse with the plasma membrane, whereas ectosomes bud directly from the plasma me...

journal_title：Biophysical journal

authors： Jackson CE,Scruggs BS,Schaffer JE,Hanson PI

更新日期：2017-09-19 00:00:00

abstract：:Intensities of x-ray scattering from a series of fragmented rabbit muscle sarcoplasmic reticulum (SR) samples have been measured over the range x = 0.05 to s = 0.25. By varying the relative concentrations of lipid and protein (chiefly the Mg++-dependent, Ca++- stimulated ATPase) in the membranes of this series, and by...

journal_title：Biophysical journal

authors： Brady GW,Fein DB,Harder ME,Spehr R,Meissner G

更新日期：1981-04-01 00:00:00

abstract：:Experimental variables of optical tweezers instrumentation that affect RNA folding/unfolding kinetics were investigated. A model RNA hairpin, P5ab, was attached to two micron-sized beads through hybrid RNA/DNA handles; one bead was trapped by dual-beam lasers and the other was held by a micropipette. Several experimen...

journal_title：Biophysical journal

authors： Wen JD,Manosas M,Li PT,Smith SB,Bustamante C,Ritort F,Tinoco I Jr

更新日期：2007-05-01 00:00:00

abstract：:Here we extend the ability to predict hydrodynamic coefficients and other solution properties of rigid macromolecular structures from atomic-level structures, implemented in the computer program HYDROPRO, to models with lower, residue-level resolution. Whereas in the former case there is one bead per nonhydrogen atom,...

journal_title：Biophysical journal

authors： Ortega A,Amorós D,García de la Torre J

更新日期：2011-08-17 00:00:00

abstract：:Many different cell types are able to migrate by formation of a thin actin-based cytoskeletal extension. Recently, it became evident that this extension consists of two distinct substructures, designated lamellipodium and lamellum, which differ significantly in their kinetic and kinematic properties as well as their b...

journal_title：Biophysical journal

authors： Huber F,Käs J,Stuhrmann B

更新日期：2008-12-15 00:00:00

abstract：:Several biologically important protein structures give rise to strong second-harmonic generation (SHG) in their native context. In addition to high-contrast optical sections of cells and tissues, SHG imaging can provide detailed structural information based on the physical constraints of the optical effect. In this st...

journal_title：Biophysical journal

authors： Plotnikov SV,Millard AC,Campagnola PJ,Mohler WA

更新日期：2006-01-15 00:00:00

abstract：:Recent development of titratable coions has paved the way for realizing all-atom molecular dynamics at constant pH. To further improve physical realism, here we describe a technique in which proton titration of the solute is directly coupled to the interconversion between water and hydroxide or hydronium. We test the ...

journal_title：Biophysical journal

authors： Chen W,Wallace JA,Yue Z,Shen JK

更新日期：2013-08-20 00:00:00

abstract：:Microbial capsules are important for virulence, but their architecture and physical properties are poorly understood. The human pathogenic fungus Cryptococcus neoformans has a large polysaccharide capsule that is necessary for virulence and is the target of protective antibody responses. To study the C. neoformans cap...

journal_title：Biophysical journal

authors： Frases S,Pontes B,Nimrichter L,Rodrigues ML,Viana NB,Casadevall A

更新日期：2009-08-19 00:00:00

abstract：:Phosphorescence spectroscopy on mouse myeloma IgA J539 in rigid solution at 77K revealed the type of anomalous short-lived component in the tryptophan decay originally observed with lysozyme (Churchich, J.E., 1966. Biochim. Biophys. Acta. 120:406-412) and seen in a large number of Bence Jones proteins (Longworth, J.W....

journal_title：Biophysical journal

authors： Li Z,Galley WC

更新日期：1989-08-01 00:00:00

abstract：:Forces applied by cells to substrates can be measured using soft substrates with embedded displacement markers. Traction forces are retrieved from microscopic images by determining the displacements of these markers and fitting the generating forces. Here we show that using elastic films of 5-10-microm thickness one c...

journal_title：Biophysical journal

authors： Merkel R,Kirchgessner N,Cesa CM,Hoffmann B

更新日期：2007-11-01 00:00:00

abstract：:We have examined the kinetics and thermodynamics of the exchange of a fluorescent amphiphile derived from a phospholipid, NBD-DMPE, between serum albumin and the serum lipoproteins of high density (HDL2 and HDL3), LDL, and VLDL. Binding of the fluorescent lipid amphiphile to bovine serum albumin is characterized, at 3...

journal_title：Biophysical journal

authors： Estronca LM,Moreno MJ,Laranjinha JA,Almeida LM,Vaz WL

更新日期：2005-01-01 00:00:00

abstract：:The pulling of micropipette electrodes from glass tubing has been treated as a problem of viscous flow coupled with the Newtonian dynamics of the pulling apparatus. Analytical solutions are given from which the taper profile, tip diameter, and pulling time can be obtained. The physical principles of operation of micro...

journal_title：Biophysical journal

authors： Purves RD

更新日期：1980-03-01 00:00:00

abstract：:Competitive hybridization, at the surface and in the bulk, lowers the sensitivity of DNA chips. Competitive surface hybridization occurs when different targets can hybridize with the same probe. Competitive bulk hybridization takes place when the targets can hybridize with free complementary chains in the solution. Th...

journal_title：Biophysical journal

authors： Halperin A,Buhot A,Zhulina EB

更新日期：2004-02-01 00:00:00

abstract：:Differentiation from a multipotent stem or progenitor state to a mature cell is an essentially irreversible process. The associated changes in gene expression patterns exhibit time-directionality. This "arrow of time" in the collective change of gene expression across multiple stable gene expression patterns (attracto...

journal_title：Biophysical journal

authors： Wang J,Xu L,Wang E,Huang S

更新日期：2010-07-07 00:00:00

abstract：:The structural changes in the photoreaction cycle of bacteriorhodopsin, a light-driven proton pump, was investigated at a resolution of 7 angstroms by a time-resolved x-ray diffraction experiment utilizing synchrotron x rays from an undulator of SPring-8. The x-ray diffraction measurement system, used in coupling with...

journal_title：Biophysical journal

authors： Oka T,Inoue K,Kataoka M,Yagi N

更新日期：2005-01-01 00:00:00

abstract：:Experiments have shown that the ability of the HIV-1 virus to infect cells can be greatly diminished by deactivation of the N-terminal (fusion) peptide of its glycoprotein gp41. Deactivation can be achieved by the deletion of several amino acid residues, or replacement of a hydrophobic residue with a polar residue, to...

journal_title：Biophysical journal

authors： Maddox MW,Longo ML

更新日期：2002-12-01 00:00:00

abstract：:Molecular dynamics simulations were performed to describe the function of the ion-channel-forming toxin α-hemolysin (αHL) in lipid membranes that were composed of either 1,2-diphytanoyl-sn-glycero-3-phospho-choline or 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-choline. The simulations highlight the importance of lipid ...

journal_title：Biophysical journal

authors： Guros NB,Balijepalli A,Klauda JB

更新日期：2018-11-06 00:00:00

abstract：:In two-color fluorescence correlation spectroscopy (TCFCS), the fluorescence intensities of two fluorescently-labeled species are cross-correlated over time and can be used to identify static and dynamic interactions. Generally, fluorophore labels are chosen that do not undergo Förster resonance energy transfer (FRET)...

journal_title：Biophysical journal

authors： Hom EF,Verkman AS

更新日期：2002-07-01 00:00:00

abstract：:We have refined the structure of the DNA Three-Way Junction complex, TWJ-TC, described in the companion paper by quantitative analysis of two 2D NOESY spectra (mixing times 60 and 200 ms) obtained in D2O solution. NOESY crosspeak intensities extracted from these spectra were used in two kinds of refinement procedure: ...

journal_title：Biophysical journal

authors： Ouporov IV,Leontis NB

更新日期：1995-01-01 00:00:00

abstract：:Biofilm infections can consist of bacterial aggregates that are an order of magnitude larger than neutrophils, phagocytic immune cells that densely surround aggregates but do not enter them. Because a neutrophil is too small to engulf the entire aggregate, it must be able to detach and engulf a few bacteria at a time ...

journal_title：Biophysical journal

authors： Davis-Fields M,Bakhtiari LA,Lan Z,Kovach KN,Wang L,Cosgriff-Hernandez EM,Gordon VD

更新日期：2019-10-15 00:00:00

abstract：:The recently developed CMAP correction to the CHARMM22 force field (C22) is evaluated from 25 ns molecular dynamics simulations on hen lysozyme. Substantial deviations from experimental backbone root mean-square fluctuations and N-H NMR order parameters obtained in the C22 trajectories (especially in the loops) are el...

journal_title：Biophysical journal

authors： Buck M,Bouguet-Bonnet S,Pastor RW,MacKerell AD Jr

更新日期：2006-02-15 00:00:00

abstract：:Infrared spectroscopy has long been used to examine the average secondary structure and orientation of membrane proteins. With the recent utilization of site-specific isotope labeling (e.g., peptidic 1-(13)C = (18)O) it is now possible to examine localized properties, rather than global averages. The technique of site...

journal_title：Biophysical journal

authors： Arbely E,Kass I,Arkin IT

更新日期：2003-10-01 00:00:00

abstract：:Members of the spectrin superfamily of proteins contain different numbers of homologous repeats arranged in tandem. Each of these consists of a three-alpha-helix motif, comprising two similarly and one oppositely directed alpha-helical segment joined by nonhelical linkers of characteristic length. The right-handed alp...

journal_title：Biophysical journal

authors： Parry DA,Dixon TW,Cohen C

更新日期：1992-04-01 00:00:00

abstract：:The structural properties of a crucial transmembrane helix for proton translocation in vacuolar ATPase are studied using double site-directed spin-labeling combined with electron spin resonance (ESR) (or electron paramagnetic resonance) and circular dichroism spectroscopy in sodium dodecyl sulfate micelles. For this p...

journal_title：Biophysical journal

authors： Vos WL,Vermeer LS,Hemminga MA

更新日期：2007-01-01 00:00:00

abstract：:Twenty-seven mutant bacteriorhodopsin's were screened to determine the PKa for reversal of the permanent electric dipole moment. The photoelectric response of an aqueous purple-membrane suspension was used to determine the direction of the purple-membrane dipole moment as a function of pH. The pK(a) for the dipole rev...

journal_title：Biophysical journal

authors： Hsu KC,Rayfield GW,Needleman R

更新日期：1996-05-01 00:00:00

abstract：:We elucidate the physics of protein dynamical transition via 10-100-ns molecular dynamics simulations at temperatures spanning 160-300 K. By tracking the energy fluctuations, we show that the protein dynamical transition is marked by a crossover from nonstationary to stationary processes that underlie the dynamics of ...

journal_title：Biophysical journal

authors： Okan OB,Atilgan AR,Atilgan C

更新日期：2009-10-07 00:00:00

abstract：:Recent experimental studies suggest that lactate dehydrogenase (LDH) binds its substrate via the formation of a LDH/NADH.substrate encounter complex through a select-fit mechanism, whereby only a minority population of LDH/NADH is binding-competent. In this study, we perform molecular dynamics calculations to explore ...

journal_title：Biophysical journal

authors： Pineda JR,Callender R,Schwartz SD

更新日期：2007-09-01 00:00:00

abstract：:Global analysis techniques are described for frequency domain fluorescence lifetime imaging microscopy (FLIM) data. These algorithms exploit the prior knowledge that only a limited number of fluorescent molecule species whose lifetimes do not vary spatially are present in the sample. Two approaches to implementing the...

journal_title：Biophysical journal

authors： Verveer PJ,Squire A,Bastiaens PI

更新日期：2000-04-01 00:00:00