Abstract:
:The design and implementation of a high-speed, random-access, laser-scanning fluorescence microscope configured to record fast physiological signals from small neuronal structures with high spatiotemporal resolution is presented. The laser-scanning capability of this nonimaging microscope is provided by two orthogonal acousto-optic deflectors under computer control. Each scanning point can be randomly accessed and has a positioning time of 3-5 microseconds. Sampling time is also computer-controlled and can be varied to maximize the signal-to-noise ratio. Acquisition rates up to 200k samples/s at 16-bit digitizing resolution are possible. The spatial resolution of this instrument is determined by the minimal spot size at the level of the preparation (i.e., 2-7 microns). Scanning points are selected interactively from a reference image collected with differential interference contrast optics and a video camera. Frame rates up to 5 kHz are easily attainable. Intrinsic variations in laser light intensity and scanning spot brightness are overcome by an on-line signal-processing scheme. Representative records obtained with this instrument by using voltage-sensitive dyes and calcium indicators demonstrate the ability to make fast, high-fidelity measurements of membrane potential and intracellular calcium at high spatial resolution (2 microns) without any temporal averaging.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Bullen A,Patel SS,Saggau Pdoi
10.1016/S0006-3495(97)78086-Xsubject
Has Abstractpub_date
1997-07-01 00:00:00pages
477-91issue
1eissn
0006-3495issn
1542-0086pii
S0006-3495(97)78086-Xjournal_volume
73pub_type
杂志文章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::A simple theoretical analysis shows that specificity of double-stranded DNA (dsDNA) targeting by homopyrimidine peptide nucleic acids (hpyPNAs) is a kinetically controlled phenomenon. Our computations give the optimum conditions for sequence-specific targeting of dsDNA by hpyPNAs. The analysis shows that, in agreement...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(97)78918-5
更新日期:1997-06-01 00:00:00
abstract::Fast Ca(2+) release kinetics were measured in cardiac sarcoplasmic reticulum vesicles actively loaded with Ca(2+). Release was induced in solutions containing 1.2 mM free ATP and variable free [Ca(2+)] and [Mg(2+)]. Release rate constants (k) were 10-fold higher at pCa 6 than at pCa 5 whereas Ryanodine binding was hig...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)75037-1
更新日期:2003-04-01 00:00:00
abstract::A single isolated sinoatrial pacemaker cell presents intrinsic interbeat interval (IBI) variability that is believed to result from the stochastic characteristics of the opening and closing processes of membrane ion channels. To our knowledge, a novel mathematical framework was developed in this work to address the ef...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2015.01.010
更新日期:2015-03-10 00:00:00
abstract::The force-extension curve of single myosin subfragment-1 molecules, interacting in the rigor state with an actin filament, has been investigated at low [ATP] by applying a slow triangle-wave movement to the optical traps holding a bead-actin-bead dumbbell. In combination with a measurement of the overall stiffness of ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.119396
更新日期:2008-03-15 00:00:00
abstract::The stability of the 1:1 complex of sodium ion with the dianion of guanosine 5'-monophosphate has been determined by means of a potentiometric titration employing a specific ion electrode. The stability constant for the reaction Na(+) + 5'-GMP(2-) Na(5'-GMP)(-) was found to be 2.85 +/- 0.36 M(-1) at 5 degrees C and an...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/s0006-3495(82)84564-5
更新日期:1982-06-01 00:00:00
abstract::The backbone dynamics for the 29.5 kDa class A beta-lactamase PSE-4 is presented. This solution NMR study was performed using multiple field (15)N spin relaxation and amide exchange data in the EX2 regime. Analysis was carried out with the relax program and includes the Lipari-Szabo model-free approach. Showing simila...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.02.068
更新日期:2009-06-03 00:00:00
abstract::Cholesterol, due to its condensing effect, is considered an important regulator of membrane thickness. Other sterols, due to their structural similarities to cholesterol, are often assumed to have a universal effect on membrane properties similar to the condensing effect of cholesterol, albeit possibly to different de...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.04.003
更新日期:2016-05-10 00:00:00
abstract::Numerous dyes are available or under development for probing the structural and functional properties of biological membranes. Exogenous chromophores adopt a range of orientations when bound to membranes, which have a drastic effect on their biophysical behavior. Here, we present a method that employs optical anisotro...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.08.003
更新日期:2012-09-05 00:00:00
abstract::Single-molecule force spectroscopy is used to probe the kinetics of receptor-ligand bonds by applying mechanical forces to an intermediate media on which the molecules reside. When this intermediate media is a live cell, the viscoelastic properties can affect the calculation of rate constants. We theoretically investi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.05.044
更新日期:2012-07-03 00:00:00
abstract::Choice of network topology for gene regulation has been a question of interest for a long time. How do simple and more complex topologies arise? In this work, we analyze the topology of the marRAB operon in Escherichia coli, which is associated with control of expression of genes associated with conferring resistance ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2015.08.017
更新日期:2015-10-06 00:00:00
abstract::Molecular chaperone Hsp70 plays important roles in the pathology of amyloid diseases by inhibiting aberrant aggregation of proteins. However, the biophysical mechanism of the interaction of Hsp70 with the intrinsically disordered proteins (IDPs) is unclear. Here, we report that Hsp70 inhibits aggregation of islet amyl...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2020.12.019
更新日期:2021-01-06 00:00:00
abstract::Tissues and cells sustain recurring mechanical loads that span a wide range of loading amplitudes and timescales as a consequence of exposure to blood flow, muscle activity, and external impact. Both tissues and cells derive their mechanical strength from fibrous protein scaffolds, which typically have a complex hiera...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.06.034
更新日期:2016-09-06 00:00:00
abstract::A computational analysis of d(GGGGTTTTGGGG)(2) guanine quadruplexes containing either lateral or diagonal four-thymidine loops was carried out using molecular dynamics (MD) simulations in explicit solvent, locally enhanced sampling (LES) simulations, systematic conformational search, and free energy molecular-mechanic...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.103.034751
更新日期:2004-07-01 00:00:00
abstract::Normally, isothermal titration calorimetry (ITC) is used to study binding reactions between two different biomolecules. Self-association processes leading to homo-oligomeric complexes have usually not been studied by ITC; instead, methods such as spectroscopy and analytical ultracentrifugation, which only provide affi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.067223
更新日期:2005-11-01 00:00:00
abstract::We present a truly quantitative fluorescence recovery after photobleaching (FRAP) model for use with the confocal laser scanning microscope based on the photobleaching of a long line segment. The line FRAP method is developed to complement the disk FRAP method reported before. Although being more subject to the influe...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.099838
更新日期:2007-03-15 00:00:00
abstract::The outer membrane of Gram-negative bacteria is of great scientific interest because it mediates the action of antimicrobial agents. The membrane surface is composed of lipopolysaccharide (LPS) molecules with negatively charged oligosaccharide headgroups. To a certain fraction, LPSs additionally display linear polysac...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2019.02.020
更新日期:2019-04-02 00:00:00
abstract::We describe a combined use of experimental and simulation techniques to configure side chains in a coiled coil structure. As already demonstrated in a previous work, x-ray diffraction patterns from hard alpha-keratin fibers in the 5.15 A meridian zone reflect the global configuration of the chi(1) dihedral angle of th...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(02)73943-X
更新日期:2002-10-01 00:00:00
abstract::The ejection of DNA from a bacterial virus (i.e., phage) into its host cell is a biologically important example of the translocation of a macromolecular chain along its length through a membrane. The simplest mechanism for this motion is diffusion, but in the case of phage ejection a significant driving force derives ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.070532
更新日期:2006-07-15 00:00:00
abstract::The outer membrane (OM) of Gram-negative bacteria is composed of lipopolysaccharide (LPS) in the outer leaflet and phospholipids in the inner leaflet. The outer membrane protein H (OprH) of Pseudomonas aeruginosa provides an increased stability to the OMs by directly interacting with LPS. Here we report the influence ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.12.006
更新日期:2017-01-24 00:00:00
abstract::N-BAR domains are protein modules that bind to and induce curvature in membranes via a charged concave surface and N-terminal amphipathic helices. Recently, molecular dynamics simulations have demonstrated that the N-BAR domain can induce a strong local curvature that matches the curvature of the BAR domain surface fa...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.121160
更新日期:2008-08-01 00:00:00
abstract::Motions through the energy landscape of proteins lead to biological function. At temperatures below a dynamical transition (150-250 K), some of these motions are arrested and the activity of some proteins ceases. Here, we introduce the technique of temperature-derivative fluorescence microspectrophotometry to investig...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(04)74365-9
更新日期:2004-05-01 00:00:00
abstract::Although the majority of free cellular cholesterol is present in the plasma membrane, cholesterol homeostasis is principally regulated through sterol-sensing proteins that reside in the cholesterol-poor endoplasmic reticulum (ER). In response to acute cholesterol loading or depletion, there is rapid equilibration betw...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2013.08.042
更新日期:2013-10-15 00:00:00
abstract::How calmodulin (CaM) acts in KRAS-driven cancers is a vastly important question. CaM binds to and stimulates PI3Kα/Akt signaling, promoting cell growth and proliferation. Phosphorylation of CaM at Tyr99 (pY99) enhances PI3Kα activation. PI3Kα is a lipid kinase. It phosphorylates PIP2 to produce PIP3, to which Akt bind...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2017.09.008
更新日期:2017-11-07 00:00:00
abstract::Encapsulation of proteins within lipid inverse bicontinuous cubic phases (Q2) has been widely studied for many applications, such as protein crystallization or drug delivery of proteins for food and pharmaceutical purposes. However, the use of the lipid sponge (L3) phase for encapsulation of proteins has not yet been ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2019.07.031
更新日期:2019-09-03 00:00:00
abstract::Plasma insulin measurements from mice, rats, dogs, and humans indicate that insulin levels are oscillatory, reflecting pulsatile insulin secretion from individual islets. An unanswered question, however, is how the activity of a population of islets is coordinated to yield coherent oscillations in plasma insulin. Here...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.05.016
更新日期:2009-08-05 00:00:00
abstract::In recent years, optical sensors for tracking neural activity have been developed and offer great utility. However, developing microscopy techniques that have several kHz bandwidth necessary to reliably capture optically reported action potentials (APs) at multiple locations in parallel remains a significant challenge...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.12.005
更新日期:2015-02-03 00:00:00
abstract::Artificial lipidic bilayers are widely used as a model for the lipid matrix in biological cell membranes. We use the Pockels electro-optical effect to investigate the properties of an artificial lipidic membrane doped with nonlinear molecules in the outer layer. We report here what is believed to be the first electro-...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.08.055
更新日期:2009-12-02 00:00:00
abstract::The photoelectron quantum yields of 21 common amino acids and 15 polyamino acids were measured in the 180-240 nm wavelength region. On the average, the quantum yields of these two groups exhibit quite similar wavelength dependence. For lambda > 220 nm all amino acid and polyamino acid quantum yields are =10(-7) elec...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(74)85927-8
更新日期:1974-06-01 00:00:00
abstract::Deuterium magnetic resonance is applied to the study of the liquid crystalline and gel phases, and of the phase transition, of a multilamellar dispersion of chain perdeuterated (d62)-dipalmitoyl phosphatidylcholine/H2O. Analysis of the deuterium spectra in terms of the moments of the spectra allows one to make quantit...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(79)85222-4
更新日期:1979-09-01 00:00:00