Abstract:
:Frog skeletal muscle fibers, mechanically skinned under water-saturated silicone oil, swell upon transfer to aqueous relaxing medium (60 mM KCl; 3 mM MgCl(2); 3 mM ATP; 4 mM EGTA; 20 mM Tris maleate; pH = 7.0; ionic strength 0.15 M). Their cross-sectional areas, estimated with an elliptical approximation, increase 2.32-fold (+/-0.54 SD). Sarcomere spacing is unaffected by this swelling. Addition of 200 mM sucrose to relaxing medium had no effect on fiber dimensions, whereas decreasing pH to 5.0 caused fibers to shrink nearly to their original (oil) size. Decreasing MgCl(2) to 0.3 mM caused fibers to swell 10%, and increasing MgCl(2) to 9 mM led to an 8% shrinkage. Increasing ionic strength to 0.29 M with KCl caused a 26% increase in cross-sectional area; decreasing ionic strength to 0.09 M had no effect. Swelling pressure was estimated with long-chain polymers, which are probably excluded from the myofilament lattice. Shrinkage in dextran T10 (number average mol wt 6,200) was transient, indicating that this polymer may penetrate into the fibers. Shrinkage in dextran T40 (number average mol wt 28,000), polyvinylpyrrolidone (PVP) K30 (number average mol wt 40,000) and dextran T70 (number average mol wt 40,300) was not transient, indicating exclusion. Maximal calcium-activated tension is decreased by 21% in PVP solutions and by 31% in dextran T40 solutions. Fibers were shrunk to their original size with 8 x 10(-2) g/cm(3) PVP K30, a concentration which, from osmometric data, corresponds to an osmotic pressure (II/RT) of 10.5 mM. As discussed in the text, we consider this our best estimate of the swelling pressure. We find that increasing ionic strength to 0.39 M with KCl decreases swelling pressure slightly, whereas decreasing ionic strength to 0.09 M has no effect. We feel these data are consistent with the idea that swelling arises from the negatively charged nature of the myofilaments, from either mutual filamentary repulsion or a Donnan-osmotic mechanism.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Godt RE,Maughan DWdoi
10.1016/S0006-3495(77)85573-2subject
Has Abstractpub_date
1977-08-01 00:00:00pages
103-16issue
2eissn
0006-3495issn
1542-0086pii
S0006-3495(77)85573-2journal_volume
19pub_type
杂志文章abstract::A-DNA is a stable alternative right-handed double helix that is favored by certain sequences (e.g., (dG)n.(dC)n) or under low humidity conditions. Earlier A-DNA structures of several DNA oligonucleotides and RNA.DNA chimeras have revealed some conformational variation that may be the result of sequence-dependent effec...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(95)79929-5
更新日期:1995-08-01 00:00:00
abstract::The demembranated (skinned) muscle fiber preparation is widely used to investigate muscle contraction because the intracellular ionic conditions can be precisely controlled. However, plasma membrane removal results in a loss of osmotic regulation, causing abnormal hydration of the myofilament lattice and its proteins....
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.08.014
更新日期:2012-09-19 00:00:00
abstract::The membrane-lytic peptide melittin has previously been shown to form pores in lipid bilayers that have been described in terms of two different structural models. In the "barrel stave" model the bilayer remains more or less flat, with the peptides penetrating across the bilayer hydrocarbon region and aggregating to f...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.049817
更新日期:2005-03-01 00:00:00
abstract::Recently various pathways of human telomere (ht) DNA folding into G-quadruplexes and of ligand binding to these structures have been proposed. However, the key issue as to the nature of forces driving the folding and recognition processes remains unanswered. In this study, structural changes of 22-mer ht-DNA fragment ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2015.05.001
更新日期:2015-06-16 00:00:00
abstract::Von Willebrand factor (VWF) is a multimeric plasma glycoprotein involved in both hemostasis and thrombosis. VWF conformational changes, especially unfolding of the A2 domain, may be required for efficient enzymatic cleavage in vivo. It has been shown that a single A2 domain unfolds at most probable unfolding forces of...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.12.4324
更新日期:2010-04-21 00:00:00
abstract::In this work, boundary element modeling is used to study the transport of highly charged rod-like model polyions of various length under a variety of different aqueous salt conditions. Transport properties considered include free solution electrophoretic mobility, translational diffusion, and the components of the "te...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)75900-0
更新日期:2001-11-01 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::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::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::This paper reports on a coupled approach to determining the structure of the gramicidin A ion channel, utilizing solid state nuclear magnetic resonance (NMR) of isotopically labeled gramicidin channels aligned parallel to the magnetic field direction, and molecular dynamics (MD). MD computations using an idealized rig...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(91)82131-2
更新日期:1991-10-01 00:00:00
abstract::Low-power continuous-wave laser radiation is used to form a very stable microbubble at the end of a specially etched and metalized optical fiber probe. We demonstrate that the microbubble, which is firmly attached to the fiber probe, can be used to benignly trap and manipulate living swine sperm cells as well as human...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.075614
更新日期:2006-05-15 00:00:00
abstract::KL(4) is a 21-residue functional peptide mimic of lung surfactant protein B, an essential protein for lowering surface tension in the alveoli. Its ability to modify lipid properties and restore lung compliance was investigated with circular dichroism, differential scanning calorimetry, and solid-state NMR spectroscopy...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2008.12.3966
更新日期:2009-05-20 00:00:00
abstract::Cationic amino acid transporters are highly selective for L-enantiomers such as L-arginine (L-Arg). Because of this stereoselectivity, little is known about the interaction of these transporters with D-isomers. To study whether these compounds can provide information on the molecular mechanism of transport, inward cur...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.09.025
更新日期:2010-11-17 00:00:00
abstract::A kinetic analysis of membrane conductance under conditions of stationary flow is presented. The semipermeable membrane is idealized as a homogeneous laminar phase separating ionic solutions on either side. It is assumed, without consideration of the mechanisms involved, that some ion species permeate the membrane whi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(65)86757-1
更新日期:1965-11-01 00:00:00
abstract::Detection algorithms are widely used for the analysis of single-channel data because they remove the background noise from the measured current signal and reconstruct the noise-free time series. Standard detection algorithms assume channels switching only between zero and full conductance. Many types of channels, howe...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80614-9
更新日期:1994-10-01 00:00:00
abstract::The initial output of a time-resolved macromolecular crystallography experiment is a time-dependent series of difference electron density maps that displays the time-dependent changes in underlying structure as a reaction progresses. The goal is to interpret such data in terms of a small number of crystallographically...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.10.053
更新日期:2011-01-19 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
abstract::There is no methodology for the estimation of the dynamic features of large-molecular-weight RNAs in homogeneous physiological media. In this report, a luminescence anisotropy-based method using a long-lifetime luminescent oligonucleotide probe for the estimation of the dynamic features of large-molecular-weight RNA i...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.062455
更新日期:2005-12-01 00:00:00
abstract::Surface and subsurface dynamics of Rat Basophilic Leukemia cells, a model system of stimulated secretion, were imaged using Scanning Force Microscopy (SFM) at a rate of 50-60 s/image. Cytoskeletal elements and organelles were tracked within quiescent cells and those activated after IgE receptor crosslinking. In additi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80964-6
更新日期:1994-05-01 00:00:00
abstract::In the first issue, on the first page of the Biophysical Journal in 1960, Cole and Moore provided the first confirmation of the Hodgkin and Huxley formulation of the sodium and potassium conductances that underlie the action potential. In addition, working with the squid giant axon, Cole and Moore noted that strong hy...
journal_title:Biophysical journal
pub_type: 历史文章,杂志文章
doi:10.1016/j.bpj.2015.07.052
更新日期:2015-10-06 00:00:00
abstract::Individual ion activities were calculated for Ca(2+) in pure solutions of CaCl(2) and in mixtures of CaCl(2) with MgCl(2) and with NaCl, using different conventions to obtain gamma(Ca2+). The results were compared with potentiometric measurements, using calcium specific electrodes. It is found that significant differe...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(68)86528-2
更新日期:1968-08-01 00:00:00
abstract::Helix-coil transitions in polyalanine molecules of length 10 are studied by multi-canonical Monte Carlo simulations. The solvation effects are included by either a distance-dependent dielectric permittivity or by a term that is proportional to the solvent-accessible surface area of the peptide. We found a strong depen...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(02)75668-3
更新日期:2002-06-01 00:00:00
abstract::We report constraints on the supramolecular structure of amyloid fibrils formed by the 40-residue beta-amyloid peptide associated with Alzheimer's disease (A beta(1-40)) obtained from solid-state nuclear magnetic resonance (NMR) measurements of intermolecular dipole-dipole couplings between (13)C labels at 11 carbon s...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(02)75244-2
更新日期:2002-08-01 00:00:00
abstract::Point mutations in p21ras are associated with ∼30% of human tumors by disrupting its GTP hydrolysis cycle, which is critical to its molecular switch function in cellular signaling pathways. In this work, we investigate the impact of Gln 61 substitutions in the structure of the p21N-ras active site and particularly foc...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2018.07.042
更新日期:2018-10-16 00:00:00
abstract::Purple membranes were adsorbed on freestanding lipid bilayers, termed nano-black lipid membranes (nano-BLMs), suspending the pores of porous alumina substrates with average pore diameters of 280 nm. Nano-BLMs were obtained by first coating the upper surface of the highly ordered porous alumina substrates with a thin g...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.059550
更新日期:2005-08-01 00:00:00
abstract::Time-resolved photovoltage measurements were performed with the acid-blue (bR605A) and acid-purple (bR565A) forms of bacteriorhodopsin (bR) in the time range from 25 ns to 100 s. The bR605A and bR565A pigments were formed by titration with H2SO4 in the absence and presence of 150 mM KCI, respectively. Qualitatively th...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(95)80077-9
更新日期:1995-11-01 00:00:00
abstract::We accelerate protein folding in all-atom molecular dynamics simulations by introducing alternating hydrogen bond potentials as a supplement to the force field. The alternating hydrogen bond potentials result in accelerated hydrogen bond reordering, which leads to rapid formation of secondary structure elements. The m...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.122192
更新日期:2008-05-15 00:00:00
abstract::Multiple data are available on the self-assembly of mixtures of bilayer-forming amphiphiles, particularly phospholipids and micelle-forming amphiphiles, commonly denoted detergents. The structure of such mixed assemblies has been thoroughly investigated, described in phase diagrams, and theoretically rationalized in t...
journal_title:Biophysical journal
pub_type: 杂志文章,评审
doi:10.1016/j.bpj.2013.06.007
更新日期:2013-07-16 00:00:00
abstract::We studied the effects of permeant ions on the gating of the large conductance Ca(2+)-activated K+ channel from rat skeletal muscle. Rb+ blockade of inward K+ current caused an increase in the open probability as though Rb+ occupancy of the pore interferes with channel closing. In support of this hypothesis, we direct...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(92)81869-6
更新日期:1992-03-01 00:00:00
abstract::Actin is ubiquitous globular protein that polymerizes into filaments and forms networks that participate in the force generation of eukaryotic cells. Such forces are used for cell motility, cytokinesis, and tissue remodeling. Among those actin networks, we focus on the actin cortex, a dense branched network beneath th...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.07.008
更新日期:2014-08-19 00:00:00