Abstract:
:We have examined the mechanisms underlying the voltage sensitivity of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptors in voltage-clamped outside-out patches and whole cells taken from the nucleus magnocellularis of the chick. Responses to either glutamate or kainate had outwardly rectifying current-voltage relations. The rate and extent of desensitization during prolonged exposure to agonist, and the rate of deactivation after brief exposure to agonist, decreased at positive potentials, suggesting that a kinetic transition was sensitive to membrane potential. Voltage dependence of the peak conductance and of the deactivation kinetics persisted when desensitization was reduced with aniracetam or blocked with cyclothiazide. Furthermore, the rate of recovery from desensitization to glutamate was not voltage dependent. Upon reduction of extracellular divalent cation concentration, kainate-evoked currents increased but preserved rectifying current-voltage relations. Rectification was strongest at lower kainate concentrations. Surprisingly, nonstationary variance analysis of desensitizing responses to glutamate or of the current deactivation after kainate removal revealed an increase in the mean single-channel conductance with more positive membrane potentials. These data indicate that the rectification of the peak response to a high agonist concentration reflects an increase in channel conductance, whereas rectification of steady-state current is dominated by voltage-sensitive channel kinetics.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Raman IM,Trussell LOdoi
10.1016/S0006-3495(95)80057-3subject
Has Abstractpub_date
1995-11-01 00:00:00pages
1868-79issue
5eissn
0006-3495issn
1542-0086pii
S0006-3495(95)80057-3journal_volume
69pub_type
杂志文章abstract::The theoretical relationships between the fluorescence and photochemical yields of PS II and the fraction of open reaction centers are examined in a general model endowed with the following features: i) a homogeneous, infinite PS II domain; ii) exciton-radical-pair equilibrium; and iii) different rates of exciton tran...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(95)80429-7
更新日期:1995-06-01 00:00:00
abstract::The use of one-dimensional electron density strip models in interpreting low-angle X-ray data from planar and concentric multilayered structures is described. Diffraction formulas for an n-strip model are given. Fourier transforms, normalization constants, and Patterson functions are derived for certain strip models. ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(69)86381-2
更新日期:1969-02-01 00:00:00
abstract::Helicobacter pylori arginase, a bimetallic enzyme, is crucial for pathogenesis of the bacterium in human stomach. Despite conservation of the signature motifs in all arginases, the H. pylori homolog has a non-conserved motif (153ESEEKAWQKLCSL165), whose role was recently shown to be critical for its stability and func...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2017.02.009
更新日期:2017-03-28 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::We investigated the accessibility to protons and thiol-directed reagents of a cysteine substituted at position 338 in transmembrane segment 6 (TM6) of CFTR to test the hypothesis that T338 resides in the pore. Xenopus oocytes expressing T338C CFTR exhibited pH-dependent changes in gCl and I-V shape that were specific ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.050534
更新日期:2004-12-01 00:00:00
abstract::The crystal structure and a 96-ps molecular dynamics simulation used to analyze structural and motional contributions to spin-lattice (T1) relaxation times of phenylalanine and tyrosine C gamma carbons of the pancreatic trypsin inhibitor. The H beta and H delta protons geminal to C gamma are calculated to account for ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(82)84496-2
更新日期:1982-07-01 00:00:00
abstract::Glasses used to fabricate patch pipettes may release components which affect ion channels (Cota, G., and C.M. Armstrong. 1988. Biophys. J. 53:107-109; Furman, R.E., and J.C. Tanaka. 1988. Biophys. J. 53:287-292; Rojas, L., and C. Zuazaga. 1988. Neurosci. Lett. 88:39-44). The gating properties of maxi K+ channels from ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(91)82127-0
更新日期:1991-10-01 00:00:00
abstract::Single-molecule methods provide direct measurements of macromolecular dynamics, but are limited by the number of degrees of freedom that can be followed at one time. High-resolution rotor bead tracking (RBT) measures DNA torque, twist, and extension, and can be used to characterize the structural dynamics of DNA and d...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2017.11.017
更新日期:2018-01-23 00:00:00
abstract::We describe a puffing method for changing solutions near one surface of lipid bilayers that allows simultaneous measurement of channel activity and extent of solution change at the bilayer surface. Ion adsorption to the lipid headgroups and screening of the bilayer surface charge by mobile ions provided a convenient p...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79271-8
更新日期:1996-08-01 00:00:00
abstract::The jaws of the bloodworm Glycera dibranchiata consist principally of protein and melanin scaffolds with small amounts of unmineralized copper (Cu) and mineralized atacamite (Cu(2)Cl(OH)(3)) fibers in distinct regions. Remarkably, when tested in air, the regions containing unmineralized Cu are the hardest, stiffest, a...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.120790
更新日期:2008-04-15 00:00:00
abstract::It is known that the action of general anesthetics is proportional to their partition coefficient in lipid membranes (Meyer-Overton rule). This solubility is, however, directly related to the depression of the temperature of the melting transition found close to body temperature in biomembranes. We propose a thermodyn...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.099754
更新日期:2007-05-01 00:00:00
abstract::Many experiments have measured the effect of force on the dissociation of single selectin bonds, but it is not yet clear how the force dependence of molecular dissociation can influence the rolling of cells expressing selectin molecules. Recent experiments using constant-force atomic force microscopy or high-resolutio...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.082321
更新日期:2007-02-01 00:00:00
abstract::T cell receptor phosphorylation by Lck is an essential step in T cell activation. It is known that the conformational states of Lck control enzymatic activity; however, the underlying principles of how Lck finds its substrate over the plasma membrane remain elusive. Here, single-particle tracking is paired with photoa...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2020.01.041
更新日期:2020-03-24 00:00:00
abstract::Video-based particle tracking monitors the microscopic movement of labeled biomolecules and fluorescent probes within a complex cellular environment. Information gained from this technique enables us to extract the dynamic behavior of biomolecules and the local mechanical properties inside the cell from a tracked part...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.03.029
更新日期:2009-06-17 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::Thermal stability of proteins is crucial for both biotechnological and therapeutic applications. Rational protein engineering therefore frequently aims at increasing thermal stability by introducing stabilizing mutations. The accurate prediction of the thermodynamic consequences caused by mutations, however, is highly...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.01.051
更新日期:2010-05-19 00:00:00
abstract::Disruption of the integrity of the plasma membrane by amyloidogenic proteins is linked to the pathogenesis of a number of common age-related diseases. Although accumulating evidence suggests that adverse environmental stressors such as unbalanced levels of metal ions may trigger amyloid-mediated membrane damage, many ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.11.3811
更新日期:2013-01-08 00:00:00
abstract::Cyclic nucleotide-gated (CNG) channels, which were initially studied in retina and olfactory neurons, are activated by cytoplasmic cGMP or cAMP. Detailed comparisons of nucleotide-activated currents using nucleotide analogs and mutagenesis revealed channel-specific residues in the nucleotide-binding domain that regula...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76778-6
更新日期:2000-05-01 00:00:00
abstract::Understanding how polypeptides can efficiently and reproducibly attain a self-entangled conformation is a compelling biophysical challenge that might shed new light on our general knowledge of protein folding. Complex lassos, namely self-entangled protein structures characterized by a covalent loop sealed by a cystein...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2019.05.025
更新日期:2019-07-23 00:00:00
abstract::Morphogenesis involves the dynamic interplay of biochemical, mechanical, and electrical processes. Here, we ask to what extent can the course of morphogenesis be modulated and controlled by an external electric field? We show that at a critical amplitude, an external electric field can halt morphogenesis in Hydra rege...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2019.09.007
更新日期:2019-10-15 00:00:00
abstract::Several hundred solid state NMR dipolar couplings and chemical shift anisotropies were simulated for the polytopic membrane protein, bacteriorhodopsin, and for an idealized transmembrane peptide conforming to several different secondary structures (alpha- and 3(10)-helices and parallel and antiparallel beta-sheets), e...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(93)81215-3
更新日期:1993-10-01 00:00:00
abstract::We present a theory for proton diffusion through an immobilized protein membrane perfused with an electrolyte and a buffer. Using a Nernst-Planck equation for each species and assuming local charge neutrality, we obtain two coupled nonlinear diffusion equations with new diffusion coefficients dependent on the concentr...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(79)85274-1
更新日期:1979-01-01 00:00:00
abstract::We present here an efficient and accurate procedure for modeling of the three-dimensional structures of polypeptides in the explicit solvent water based on molecular dynamics calculations. Using the toxic domain analog of heat-stable enterotoxin as a model peptide, we examined the utilities of two molecular dynamics t...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80975-0
更新日期:1994-06-01 00:00:00
abstract::In ubiquitination, cullin-RING E3 ubiquitin ligases (CRLs) assist in ubiquitin transfer from ubiquitin-conjugating enzyme E2 to the substrate. Neddylation, which involves NEDD8 transfer from E2 to E3-cullin, stimulates ubiquitination by inducing conformational change in CRLs. However, deneddylation, which removes NEDD...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.05.021
更新日期:2010-08-04 00:00:00
abstract::Polypeptide toxins isolated from the venom of cone snails, known as μ-conotoxins, block voltage-gated sodium channels by physically occluding the ion-conducting pathway. Using molecular dynamics, we show that one subtype of μ-conotoxins, PIIIA, effectively blocks the bacterial voltage-gated sodium channel Na(V)Ab, who...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.12.041
更新日期:2012-02-08 00:00:00
abstract::We aimed to investigate insulin amyloid fibril polymorphism caused by salt effects and heating temperature and to visualize the structural differences of the polymorphisms in situ using Raman imaging without labeling. The time course monitoring for amyloid formation was carried out in an acidic condition without any s...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2020.04.031
更新日期:2020-06-16 00:00:00
abstract::Mechanosensitivity in voltage-gated calcium channels could be an asset to calcium signaling in healthy cells or a liability during trauma. Recombinant N-type channels expressed in HEK cells revealed a spectrum of mechano-responses. When hydrostatic pressure inflated cells under whole-cell clamp, capacitance was unchan...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(02)75267-3
更新日期:2002-11-01 00:00:00
abstract::Specific amino acid sequence segments have been assigned to locations in the structural map of bacteriorhodopsin using two-dimensional neutron diffraction data and a model building analysis. Models are constructed computationally by building specific regions of the amino acid sequence as alpha helices and then positio...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(83)84391-4
更新日期:1983-06-01 00:00:00
abstract::A master equation theory is formulated to describe the dependence of the fluorescence yield (phi) in photosynthetic systems on the number of photons (Y) absorbed per photosynthetic unit (or domain). This theory is applied to the calculation of the dependence of the fluorescence yield on Y in (a) fluorescence induction...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(83)84278-7
更新日期:1983-10-01 00:00:00
abstract::Articular cartilage is the connective tissue that lines joints and provides a smooth surface for joint motion. Because cartilage is avascular, molecular transport occurs primarily via diffusion or convection, and cartilage matrix structure and composition may affect diffusive transport. Because of the inhomogeneous co...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.108.137752
更新日期:2008-11-15 00:00:00