Abstract:
:The current-voltage (I-V) relation of the background current, IK1, was studied in isolated canine cardiac Purkinje myocytes using the whole-cell, patch-clamp technique. Since Ba2+ and Cs+ block IK1, these cations were used to separate the I-V relation of IK1 from that of the whole cell. The I-V relation of IK1 was measured as the difference between the I-V relations of the cell in normal Tyrode (control solution) and in the presence of either Ba2+ (1 mM) or Cs+ (10 mM). Our results indicate that IK1 is an inwardly rectifying K+ current whose conductance depends on extracellular potassium concentration. In different [K+]0's the I-V relations of IK1 exhibit crossover. In addition the I-V relation of IK1 contains a region of negative slope (even when that of the whole cell does not). We also examined the relationship between the resting potential of the myocyte, Vm, and [K+]0 and found that it exhibits the characteristic anomalous behavior first reported in Purkinje strands (Weidmann, S., 1956, Elektrophysiologie der Herzmuskelfaser, Med. Verlag H. Huber), where lowering [K+]0 below 4 mM results in a depolarization.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Shah AK,Cohen IS,Datyner NBdoi
10.1016/S0006-3495(87)83241-1subject
Has Abstractpub_date
1987-10-01 00:00:00pages
519-25issue
4eissn
0006-3495issn
1542-0086pii
S0006-3495(87)83241-1journal_volume
52pub_type
杂志文章abstract::Aggregated Markov models are a widely used tool to model patch clamp data measured from single ion channels. These channels must obey the principle of detailed balance in thermodynamic equilibrium; otherwise, the channel is driven by an external source of energy. We investigate the power of a likelihood ratio test for...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76529-5
更新日期:2000-12-01 00:00:00
abstract::The regulatory mechanism of sarcomeric activity has not been fully clarified yet because of its complex and cooperative nature, which involves both Ca(2+) and cross-bridge binding to the thin filament. To reveal the mechanism of regulation mediated by the cross-bridges, separately from the effect of Ca(2+), we investi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.110650
更新日期:2007-12-15 00:00:00
abstract::We present in this report a detailed structural study of calf gamma-crystallins both in the solid state and in solution by the newly developed technique of near-infrared (IR) Fourier transform (FT)-Raman spectroscopy as well as by the conventional Raman method. In comparison with conventional laser Raman spectroscopy,...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(91)82071-9
更新日期:1991-08-01 00:00:00
abstract::The electric quadrupole moment of the deuterium nucleus provides a nuclear magnetic resonance (NMR) probe of electric field gradients, and thereby of organization of tissue water. 8-17% of H(2)O in rat muscle and brain was replaced by D(2)O from 50% deuterated drinking water. The peak height of the steady-state NMR sp...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(69)86388-5
更新日期:1969-03-01 00:00:00
abstract::Using a method they developed, Stamatoff and Krimm (1976) have phased swelling data from nerve myelin. Although most phases agree with those I determined previously, there are a few differences. In this letter the two different phasings, theirs and my own, are used to compute the corresponding electron-density profile...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(79)85242-X
更新日期:1979-04-01 00:00:00
abstract::One of the unusual properties of elastin is its ability to coacervate, which has been proposed to play an important role in the alignment of monomeric elastin for cross-linking into the polymeric elastin matrix. The temperature at which this transition takes place depends on several factors including protein concentra...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.110809
更新日期:2007-11-15 00:00:00
abstract::Electric field pulses have been reported to induce long-lived permeabilization and fusogenicity on cell membranes. The two membrane property alterations are under the control of the field strength, the pulse duration, and the number of pulses. Experiments on mammalian cells pulsed by square wave form pulses and then b...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)77898-1
更新日期:1998-04-01 00:00:00
abstract::The general theory (Levitt, D. G. 1990. Biophys. J. 59:271-277) is applied to a model channel that resembles the acetylcholine receptor channel (ACH). The model incorporates the known features of the ACH geometry and fixed charge locations. The channel has a wide mouth facing the outer solution, tapering to a narrow r...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(91)82221-4
更新日期:1991-02-01 00:00:00
abstract::Over the last decade, functionally designed DNA nanostructures applied to lipid membranes prompted important achievements in the fields of biophysics and synthetic biology. Taking advantage of the universal rules for self-assembly of complementary oligonucleotides, DNA has proven to be an extremely versatile biocompat...
journal_title:Biophysical journal
pub_type: 杂志文章,评审
doi:10.1016/j.bpj.2016.03.015
更新日期:2016-04-26 00:00:00
abstract::This paper describes a new technique that can be used to study chloroplast volume regulation in vivo. Nuclear magnetic resonance spectroscopy was used to measure relative amounts of chloroplast water in Acer platanoides leaves as they dried in air, and also in leaf disks exposed to aqueous polyethylene glycol, sucrose...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(92)81930-6
更新日期:1992-05-01 00:00:00
abstract::In this study stereochemically pure d-erythro-sphingomyelins (SMs) with either 16:0 or 18:1(cisDelta9) as the N-linked acyl-chain were synthesized. Our purpose was to examine the properties of these sphingomyelins and acyl-chain matched racemic (d-erythro/l-threo) sphingomyelins in model membranes. Liquid-expanded d-e...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(99)76997-3
更新日期:1999-09-01 00:00:00
abstract::The arrangement of side chains in alpha-helical regions of protein can be represented by helical net-diagrams. The addition of quantitative indices of the character of the residue at each net-point facilitates a straightforward examination of the groupings of residues of different character. As such the method complem...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(68)86525-7
更新日期:1968-07-01 00:00:00
abstract::The efficiency of various patterns of pulsatile stimulation is determined in a model in which a receptor becomes desensitized in the presence of its stimulatory ligand. The effect of stochastic or chaotic changes in the duration and/or interval between successive pulses in a series of square-wave stimuli is investigat...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(92)81824-6
更新日期:1992-01-01 00:00:00
abstract::Cells within fibrocartilaginous tissues, including chondrocytes and fibroblasts of the meniscus, ligament, and tendon, regulate cell biosynthesis in response to local mechanical stimuli. The processes by which an applied mechanical load is transferred through the extracellular matrix to the environment of a cell are n...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.126938
更新日期:2008-08-01 00:00:00
abstract::The nuclear magnetic resonance (NMR) of water protons in live and glycerinated muscle, suspensions of glycerinated myofibrils, and solutions of several muscle proteins has been studied. T(1) and T(2), measured on partially hydrated proteins by pulsed spin-echo techniques, decreased as the ratio of water to protein dec...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(71)86274-4
更新日期:1971-12-01 00:00:00
abstract::This paper is concerned with the nature of the transmembrane potential induced in an inactive nerve fiber lying in an impressed potential field within a nerve trunk. The impressed potential field is assumed to be produced by the synchronous activity of other fibers within the trunk; an expression for the induced trans...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(71)86214-8
更新日期:1971-03-01 00:00:00
abstract::We report on the application of two photon molecular excitation to fluorescence correlation spectroscopy. We demonstrate the first fluorescence correlation spectroscopy measurements of translational mobility in the cytoplasm of living cells. Two-photon excitation inherently excites small sample volumes in three dimens...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(95)80230-4
更新日期:1995-02-01 00:00:00
abstract::We have examined the morphology and osmotic properties of large unilamellar vesicles (LUVs) prepared by extrusion. Contrary to expectations, we observe by cryo-electron microscopy that such vesicles, under isoosmotic conditions, are non-spherical. This morphology appears to be a consequence of vesicle passage through ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(93)81385-7
更新日期:1993-02-01 00:00:00
abstract::Nonconfluent fibroblasts are relatively depolarized when compared with confluent fibroblasts, and transient hyperpolarizations result from a range of external stimuli as well as internal cellular activities. This electrical activity ceases, along with growth and mitogenic activity, when the cells become confluent. A c...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(88)82944-8
更新日期:1988-07-01 00:00:00
abstract::Previously (Hines, M., and J.J. Blum 1983, Biophys. J., 41:67-79), a method was developed that allowed one to compute curvature and twist for a three-dimensional sliding filament model. In that formalism it was difficult to specify the shear and bending moments arising from moment-bearing interfilament links such as f...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(84)84054-0
更新日期:1984-11-01 00:00:00
abstract::Interactions of membrane anchored molecules such as glycolipids with a membrane surface are important in determining headgroup conformation. It is therefore essential to represent these membrane surface interactions in molecular modeling studies of glycolipids and other membrane bound molecules. We introduce here an e...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(92)81729-0
更新日期:1992-12-01 00:00:00
abstract::Precise information regarding the transmembrane topology of mitochondrial porin is essential for understanding the mechanisms by which this protein functions. Porin acts as a channel in the outer membrane and interacts with small solutes and proteins to regulate mitochondrial function. The acquisition of high-resoluti...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.115196
更新日期:2008-01-15 00:00:00
abstract::The information theory measure of transfer entropy is used to extract the causality of correlated motions from molecular dynamics simulations. For each pair of correlated residues, the method quantifies which residue drives the correlated motions, and which residue responds. The measure reveals how correlated motions ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.07.019
更新日期:2009-09-16 00:00:00
abstract::2H-nuclear magnetic resonance (NMR) has been used to study the dynamics of amino acid residues in bacteriorhodopsin with results that depend on the method of sample preparation. We show here that in [2H]-leucine-labeled samples the intensity of the isotropic signal varies according to the degree of residual contaminat...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(87)83278-2
更新日期:1987-11-01 00:00:00
abstract::In the absence of atomic structures of high-density lipoproteins in their lipid-bound states, many molecular models have been produced based on experimental data. Using molecular dynamics, we show that a recently proposed "solar-flares" model of discoidal high-density lipoprotein is implausible. Our simulations show a...
journal_title:Biophysical journal
pub_type: 信件
doi:10.1529/biophysj.108.131581
更新日期:2008-06-01 00:00:00
abstract::We measured the viscoelastic properties of the cytoplasm of J774 macrophages with a recently developed microrheometer. Ferromagnetic beads (1.3 microm in diameter) were used to determine the local viscoelastic moduli. Step-force pulses were applied to the magnetic beads and the displacement was observed by single part...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(99)77225-5
更新日期:1999-01-01 00:00:00
abstract::Formation of protrusions and protein segregation on the membrane is of a great importance for the functioning of the living cell. This is most evident in recent experiments that show the effects of the mechanical properties of the surrounding substrate on cell morphology. We propose a mechanism for the formation of me...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.113282
更新日期:2007-12-01 00:00:00
abstract::BP100 (KKLFKKILKYL-NH(2)) is a short cecropin A-melittin hybrid peptide, obtained through a combinatorial chemistry approach, which is highly effective in inhibiting both the in vitro and in vivo growth of economically important plant pathogenic Gram-negatives. The intrinsic Tyr fluorescence of BP100 was taken advanta...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2008.11.053
更新日期:2009-03-04 00:00:00
abstract::Fusion is a crucial event in the infection of animal cells by enveloped viruses (e.g., HIV or influenza). Viral fusion is mediated by glycoproteins, spanning the viral envelope, which attach to a membrane surface and induce fusion of the viral envelope to the cellular membrane. Influenza fusion protein (hemagglutinin)...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(97)78175-X
更新日期:1997-09-01 00:00:00
abstract::Theories of DNA electrophoretic separations generally treat the DNA as a free draining polymer moving in an electric field at a rate that depends on the effective charge density of the molecule. Separations can occur in sieving media ranging from ultradilute polymer solutions to tightly cross-linked gels. It has recen...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.040014
更新日期:2004-07-01 00:00:00