Abstract:
:We have previously studied single, voltage-dependent, saxitoxin-(STX) blockable sodium channels from rat brain in planar lipid bilayers, and found that channel block by STX was voltage-dependent. Here we describe the effect of voltage on the degree of block and on the kinetics of the blocking reaction. From their voltage dependence and kinetics, it was possible to distinguish single-channel current fluctuations due to blocking and unblocking of the channels by STX from those caused by intrinsic channel gating. The use of batrachotoxin (BTX) to inhibit sodium-channel inactivation allowed recordings of stationary fluctuations over extended periods of time. In a range of membrane potentials where the channels were open greater than 98% of the time, STX block was voltage-dependent, provided sufficient time was allowed to reach a steady state. Hyperpolarizing potentials favored block. Both association (blocking) and dissociation (unblocking) rate constants were voltage-dependent. The equilibrium dissociation constants computed from the association and dissociation rate constants for STX block were about the same as those determined from the steady-state fractional reduction in current. The steepness of the voltage dependence was consistent with the divalent toxin sensing 30-40% of the transmembrane potential.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
French RJ,Worley JF 3rd,Krueger BKdoi
10.1016/S0006-3495(84)84156-9subject
Has Abstractpub_date
1984-01-01 00:00:00pages
301-10issue
1eissn
0006-3495issn
1542-0086pii
S0006-3495(84)84156-9journal_volume
45pub_type
杂志文章abstract::The bonding rules for actin filament bundles do not lead to a particular packing symmetry, but allow for either regular or disordered filament packing. Indeed, both hexagonal and disordered types of packing are observed in vivo. To investigate factors which control bundle order, as well as size, we examined the effect...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(91)82239-1
更新日期:1991-02-01 00:00:00
abstract::We developed a multicellular model characterized by a high degree of heterogeneity to investigate possible mechanisms that underlie circadian network synchronization and rhythmicity in the suprachiasmatic nucleus (SCN). We populated a two-dimensional grid with 400 model neurons coupled via γ-aminobutyric acid (GABA) a...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.04.051
更新日期:2011-07-06 00:00:00
abstract::Nanopatterned surfaces are believed to kill bacteria through physical deformation, a mechanism that has immense potential against biochemical resistance. Because of its elusive nature, this mechanism is mostly understood through biophysical modeling. Problematically, accurate descriptions of the contact mechanics and ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2020.12.003
更新日期:2021-01-19 00:00:00
abstract::Many proteins "bind" DNA through positively charged amino acids on their surfaces. However, to overcome significant energetic and topological obstacles, proteins that bend or package DNA might also modulate the stiffness that is generated by repulsions between phosphates within DNA. Much previous work describes how io...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.064667
更新日期:2005-10-01 00:00:00
abstract::The (31)P-nuclear magnetic resonance chemical shift of phosphatidic acid in a membrane is sensitive to the lipid head group packing and can report qualitatively on membrane lateral compression near the aqueous interface. We have used high-resolution (31)P-nuclear magnetic resonance to evaluate the lateral compression ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(02)73915-5
更新日期:2002-09-01 00:00:00
abstract::Tet repressor (TetR) is involved in the most abundant mechanism of tetracycline (Tc) resistance of gram-negative bacteria. Raman spectra were measured for the class D TetR protein, for an oligodeoxyribonucleotide with sequence corresponding to operator site O1, and for the TetR:oligonucleotide complex. TetR forms a co...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)77767-7
更新日期:1998-01-01 00:00:00
abstract::Ca2+ release from the endoplasmic reticulum (ER) contributes to Ca2+ transients in frog sympathetic ganglion neurons. Here we use video-rate confocal fluo-4 fluorescence imaging to show that single action potentials reproducibly trigger rapidly rising Ca2+ transients at 1-3 local hot spots within the peripheral ER-ric...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(04)74094-1
更新日期:2004-01-01 00:00:00
abstract::In this article, optimization-based frameworks are introduced for elucidating the input-output structure of signaling networks and for pinpointing targeted disruptions leading to the silencing of undesirable outputs in therapeutic interventions. The frameworks are demonstrated on a large-scale reconstruction of a sign...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.069724
更新日期:2006-07-01 00:00:00
abstract::Cationic antimicrobial cationic peptides (CAMP) have been found in recent years to play a decisive role in hosts' defense against microbial infection. They have also been investigated as a new therapeutic tool, necessary in particular due to the increasing resistance of microbiological populations to antibiotics. The ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.095711
更新日期:2007-04-15 00:00:00
abstract::The membrane protein bacteriorhodopsin (BR) can be kept soluble in its native state for months in the absence of detergent by amphipol (APol) A8-35, an amphiphilic polymer. After an actinic flash, A8-35-complexed BR undergoes a complete photocycle, with kinetics intermediate between that in detergent solution and that...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.121848
更新日期:2008-05-01 00:00:00
abstract::Recent studies suggest that phosphoinositide kinases may participate in intracellular trafficking or exocytotic events. Because both of these events ultimately require fusion of biological membranes, the susceptibility of membranes containing polyphosphoinositides (PPIs) to divalent cation-induced fusion was investiga...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79513-9
更新日期:1996-12-01 00:00:00
abstract::Recent studies have demonstrated that caffeine can act as an antimutagen and inhibit the cytoxic and/or cytostatic effects of some DNA intercalating agents. It has been suggested that this inhibitory effect may be due to complexation of the DNA intercalator with caffeine. In this study we employ optical absorption, fl...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79587-5
更新日期:1996-01-01 00:00:00
abstract::The binding mechanism of sweet proteins to their receptor, a G-protein-coupled receptor, is not supported by direct structural information. In principle, the key groups responsible for biological activity (glucophores) can be localized on a small structural unit (sweet finger) or spread on a larger surface area. A rec...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.073171
更新日期:2006-05-01 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::The mouse major urinary protein (MUP) has proved to be an intriguing test bed for detailed studies on protein-ligand recognition. NMR, calorimetric, and modeling investigations have revealed that the thermodynamics of ligand binding involve a complex interplay between competing enthalpic and entropic terms. We perform...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.03.055
更新日期:2010-07-07 00:00:00
abstract::Platinum-containing molecules are widely used as anticancer drugs. These molecules exert cytotoxic effects by binding to DNA through various mechanisms. The binding between DNA and platinum-based drugs hinders the opening of DNA, and therefore, DNA duplication and transcription are severely hampered. Overall, impeding...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.02.030
更新日期:2016-05-24 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
abstract::Here, we present a structural and dynamic description of CBP-ID4 at atomic resolution. ID4 is the fourth intrinsically disordered linker of CREB-binding protein (CBP). In spite of the largely disordered nature of CBP-ID4, NMR chemical shifts and relaxation measurements show a significant degree of α-helix sampling in ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2015.11.3516
更新日期:2016-01-19 00:00:00
abstract::The activity of the voltage-gated Na+ channel is subjected to modulation through covalent modifications. It has been previously shown that brain Na+ currents are reduced following the activation of the protein kinase A (PKA) pathway, but the effect of the phosphorylation on the gating mechanism of the channel has not ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(99)76882-7
更新日期:1999-07-01 00:00:00
abstract::The dynamic packaging of DNA into chromatin is a key determinant of eukaryotic gene regulation and epigenetic inheritance. Nucleosomes are the basic unit of chromatin, and therefore the accessible states of the nucleosome must be the starting point for mechanistic models regarding these essential processes. Although t...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.05.042
更新日期:2014-07-15 00:00:00
abstract::The statistical mechanics of cross-bridge action is considered in order to develop constitutive equations that express fiber tension as a function of degree of activation and time history of speed of contraction. The kinetic equation of A.F. Huxley (1) is generalized to apply to the partially activated state. The rate...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/s0006-3495(85)83895-9
更新日期:1985-02-01 00:00:00
abstract::Beat-to-beat alternation of the action potential duration (APD) in paced cardiac cells has been linked to the onset of lethal arrhythmias. Both experimental and theoretical studies have shown that alternans at the single cell level can be caused by unstable membrane voltage (V(m)) dynamics linked to steep APD-restitut...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.100982
更新日期:2007-02-15 00:00:00
abstract::The motor head of kinesin carries out microtubule binding, ATP hydrolysis, and force generation. Despite a high level of sequence and structural conservation, subtle variations in subdomains of the motor head determine family-specific properties. In particular, both Kinesin-1 (Kin-1) and Kinesin-5 (Kin-5) walk process...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2013.03.051
更新日期:2013-05-07 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
pub_type: 杂志文章
doi:10.1016/j.bpj.2020.12.013
更新日期:2021-01-11 00:00:00
abstract::The morphological features of α-synuclein (AS) amyloid aggregation in vitro and in cells were elucidated at the nanoscale by far-field subdiffraction fluorescence localization microscopy. Labeling AS with rhodamine spiroamide probes allowed us to image AS fibrillar structures by fluorescence stochastic nanoscopy with ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.03.010
更新日期:2012-04-04 00:00:00
abstract::Neuronal synapses are highly specialized structures for communication between nerve cells. Knowledge about their molecular organization and dynamics is still incomplete. The large multidomain protein Bassoon plays a major role in scaffolding and organizing the cytomatrix at the active zone of neurotransmitter release ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.111674
更新日期:2008-02-15 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::Many studies of specific protein-nucleic acid binding use short oligonucleotides or restriction fragments, in part to minimize the potential for nonspecific binding of the protein. However, when the specificity ratio is low, multiple nonspecifically bound proteins may occupy the region of DNA corresponding to one spec...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)75847-X
更新日期:2001-10-01 00:00:00
abstract::One of the most common swimming strategies employed by microorganisms is based on the use of rotating helical filaments, called flagella, that are powered by molecular motors. Determining the physical properties of this propulsive system is crucial to understanding the behavior of these organisms. Furthermore, the abi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2019.08.036
更新日期:2019-10-01 00:00:00
abstract::The propagation of sounds and pulse waves within the cardiovascular system is subject to strong dissipative mechanisms. To investigate the effects of blood viscosity on dissipation as well as dispersion of small waves in arteries and veins, a parametric study has been carried out. A linearized analysis of axisymmetric...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/s0006-3495(71)86279-3
更新日期:1971-12-01 00:00:00