Abstract:
:The photophysics of the complex forming reaction of Ca2+ and Fura-2 are investigated using steady-state and time-resolved fluorescence measurements. The fluorescence decay traces were analyzed with global compartmental analysis yielding the following values for the rate constants at room temperature in aqueous solution with BAPTA as Ca2+ buffer: k01 = 1.2 x 10(9)s-1, k21 = 1.0 x 10(11) M-1 s-1, k02 = 5.5 x 10(8) s-1, k12 = 2.2 x 10(7) s-1, and with EGTA as Ca2+ buffer: k01 = 1.4 x 10(9) s-1, k21 = 5.0 x 10(10) M-1 s-1, k02 = 5.5 x 10(8) s-1, k12 = 3.2 x 10(7) s-1. k01 and k02 denote the respective deactivation rate constants of the Ca2+ free and bound forms of Fura-2 in the excited state. k21 represents the second-order rate constant of binding of Ca2+ and Fura-2 in the excited state, whereas k12 is the first-order rate constant of dissociation of the excited Ca2+:Fura-2 complex. The ionic strength of the solution was shown not to influence the recovered values of the rate constants. From the estimated values of k12 and k21, the dissociation constant K*d in the excited state was calculated. It was found that in EGTA Ca2+ buffer pK*d (3.2) is smaller than pKd (6.9) and that there is negligible interference of the excited-state reaction with the determination of Kd and [Ca2+] from fluorimetric titration curves. Hence, Fura-2 can be safely used as an Ca2+ indicator. From the obtained fluorescence decay parameters and the steady-state excitation spectra, the species-associated excitation spectra of the Ca2+ free and bound forms of Fura-2 were calculated at intermediate Ca2+ concentrations.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Van den Bergh V,Boens N,De Schryver FC,Ameloot M,Steels P,Gallay J,Vincent M,Kowalczyk Adoi
10.1016/S0006-3495(95)80285-7subject
Has Abstractpub_date
1995-03-01 00:00:00pages
1110-9issue
3eissn
0006-3495issn
1542-0086pii
S0006-3495(95)80285-7journal_volume
68pub_type
杂志文章abstract::Object contrast is one of the most important parameters of macromolecular imaging. Low-voltage transmission electron microscopy has shown an increased atom contrast for carbon materials, indicating that amplitude contrast contributions increase at a higher rate than phase contrast and inelastic scattering. Here, we st...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.01.023
更新日期:2016-02-23 00:00:00
abstract::The E462R mutation in the fifth position of the AID (alpha1 subunit interaction domain) region in the I-II linker is known to significantly accelerate voltage-dependent inactivation (VDI) kinetics of the L-type CaV1.2 channel, suggesting that the AID region could participate in a hinged-lid type inactivation mechanism...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.045559
更新日期:2004-11-01 00:00:00
abstract::Most, but not all, ion channels appear to obey the law of microscopic reversibility (or detailed balance). During the fitting of reaction mechanisms it is therefore often required that cycles in the mechanism should obey microscopic reversibility at all times. In complex reaction mechanisms, especially those that cont...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.103.038679
更新日期:2004-06-01 00:00:00
abstract::Based on differences between the x-ray crystal structures of ligand-bound and unbound forms, the activation of the erythropoietin receptor (EPOR) was initially proposed to involve a cross-action scissorlike motion. However, the validity of the motions involved in the scissorlike model has been recently challenged. Her...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.12.042
更新日期:2017-02-28 00:00:00
abstract::The processes of cell growth and budding of the yeast cells Saccharomyces cerevisiae, which were gently immobilized on 3% agar and submerged in culture medium, were successfully imaged with an atomic force microscope for 6-7 h. Similar experiments on chemically fixed cells did not detect any appreciable change in thei...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(95)80147-5
更新日期:1995-12-01 00:00:00
abstract::We have studied the large increase in macroscopic potassium channel current caused by catecholamines in mammalian cardiac cells. An increase in macroscopic K current could result from either an increase in the single-channel current or by an increase in the number of channels that are open. Therefore, we have measured...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(89)82872-3
更新日期:1989-04-01 00:00:00
abstract::The coupling between the mechanical properties of enzymes and their biological activity is a well-established feature that has been the object of numerous experimental and theoretical works. In particular, recent experiments show that enzymatic function can be modulated anisotropically by mechanical stress. We study s...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.09.026
更新日期:2010-11-17 00:00:00
abstract::We introduce here a novel Monte Carlo simulation method for studying the interactions of hydrophobic peptides with lipid membranes. Each of the peptide's amino acids is represented as two interaction sites: one corresponding to the backbone alpha-carbon and the other to the side chain, with the membrane represented as...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74765-1
更新日期:2003-12-01 00:00:00
abstract::The photochemical reaction process of bacteriorhodopsin in the nanosecond time range (-120-860 ns) was measured in the 1400-900 cm-1 region with an improved time resolved dispersive-type infrared spectrometer. The system is equipped with a newly developed detection unit whose instrumental response to a 5-ns laser puls...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(95)80386-3
更新日期:1995-05-01 00:00:00
abstract::The effects of cholesterol (Chol) on phospholipid bilayers include ordering of the fatty acyl chains, condensing of the lipids in the bilayer plane, and promotion of the liquid-ordered phase. These effects depend on the type of phospholipids in the bilayer and are determined by the nature of the underlying molecular i...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.088427
更新日期:2007-02-15 00:00:00
abstract::Intramolecular electron transfer between CuA and heme a in solubilized bacterial (Paracoccus denitrificans) cytochrome c oxidase was investigated by pulse radiolysis. CuA, the initial electron acceptor, was reduced by 1-methylnicotinamide radicals in a diffusion-controlled reaction, as monitored by absorption changes ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.075440
更新日期:2006-03-15 00:00:00
abstract::hbAP0 is a model membrane protein designed to possess an anesthetic-binding cavity in its hydrophilic domain and a cation channel in its hydrophobic domain. Grazing incidence x-ray diffraction shows that hbAP0 forms four-helix bundles that are vectorially oriented within Langmuir monolayers at the air-water interface....
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.072348
更新日期:2006-05-01 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::Two mechanisms have been proposed to account for solute permeation of lipid bilayers. Partitioning into the hydrophobic phase of the bilayer, followed by diffusion, is accepted by many for the permeation of water and other small neutral solutes, but transient pores have also been proposed to account for both water and...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79575-9
更新日期:1996-01-01 00:00:00
abstract::A fundamental question concerning the ClC Cl-/H+ antiporters is the nature of their proton transport (PT) pathway. We addressed this issue by using a novel computational methodology capable of describing the explicit PT dynamics in the ClC-ec1 protein. The main result is that the Glu203 residue delivers a proton from ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.04.038
更新日期:2009-07-08 00:00:00
abstract::Investigations into the spatiotemporal dynamics of DNA repair using live-cell imaging are aided by the ability to generate well defined regions of ultravioletlike photolesions in an optical microscope. We demonstrate that multiphoton excitation of DNA in live cells with visible femtosecond pulses produces thymine cycl...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.09.031
更新日期:2011-11-02 00:00:00
abstract::Voltage-gated sodium channels undergo transitions between open, closed, and inactivated states, enabling regulation of the translocation of sodium ions across membranes. A recently published crystal structure of the full-length prokaryotic NavMs crystal structure in the activated open conformation has revealed the pre...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2018.10.001
更新日期:2018-11-20 00:00:00
abstract::Halorhodopsin (HR) and sensory rhodopsin (SR) have been regenerated with retinal analogues that are covalently locked in the 6-s-cis or 6-s-trans conformations. Both pigments regenerate more completely with the locked 6-s-trans retinal and produce analogue pigments with absorption maxima (577 nm for HR and 592 nm for ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(89)82791-2
更新日期:1989-01-01 00:00:00
abstract::A novel way to model permeation through ionic channels is formulated. Our method does not require that equilibrium exists in the channel or at the channel interfaces. In addition, the potential profile does not need to be specified and the assumption of constant field across the membrane does not need to be made. Our ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(93)81095-6
更新日期:1993-08-01 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::Prion diseases are infectious fatal neurodegenerative diseases including Creutzfeldt-Jakob disease in humans and bovine spongiform encephalopathy in cattle. The misfolding and conversion of cellular PrP in such mammals into pathogenic PrP is believed to be the key procedure. Rabbits are among the few mammalian species...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.08.018
更新日期:2011-09-21 00:00:00
abstract::The effects of ultraviolet light (UV) irradiation on the rate of DNA replication in synchronized Chinese hamster ovary (CHO) cells were investigated. A technique for measuring semiconservative DNA replication was employed that involved growing the cells in medium containing 5-bromodeoxyuridine and subsequently determi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(76)85706-2
更新日期:1976-05-01 00:00:00
abstract::Potentiometric titrations and surface potential measurements have been used to determine the intrinsic pKa values of both the carboxyl and amino groups of phosphatidylserine (PS) in mixed vesicles of PS and phosphatidylcholine (PC), and also of the amino group of phosphatidylethanolamine (PE) in mixed PE-PC vesicles. ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(86)83655-4
更新日期:1986-02-01 00:00:00
abstract::We report the deposition of lipid monolayers and bilayers on polyacrylamide films deposited by radical chain reaction onto solid substrates in aqueous solutions. Polymer films of various degrees of monomer density and cross-linking are prepared. Lateral diffusion and fluorescent probe permeation measurements yield ins...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80472-2
更新日期:1994-07-01 00:00:00
abstract::The organization of filamentous actin and myosin II molecular motor contractility is known to modify the mechanical properties of the cell cortical actomyosin cytoskeleton. Here we describe a novel method, to our knowledge, for using force spectroscopy approach curves with tipless cantilevers to determine the actomyos...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.04.034
更新日期:2016-06-07 00:00:00
abstract::Many organisms are able to survive subzero temperatures at which bodily fluids would normally be expected to freeze. These organisms have adapted to these lower temperatures by synthesizing antifreeze proteins (AFPs), capable of binding to ice, which make further growth of ice energetically unfavorable. To date, the s...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)75821-3
更新日期:2001-09-01 00:00:00
abstract::Numerous isotypes of the structural protein tubulin have now been characterized in various organisms and their expression offers a plausible explanation for observed differences affecting microtubule function in vivo. While this is an attractive hypothesis, there are only a handful of studies demonstrating a direct in...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.108.132233
更新日期:2008-08-01 00:00:00
abstract::Extracellular vesicles (EVs) are proposed to play important roles in intercellular communication. Two classes of EVs can be distinguished based on their intracellular origin. Exosomes are generated within endosomes and released when these fuse with the plasma membrane, whereas ectosomes bud directly from the plasma me...
journal_title:Biophysical journal
pub_type: 评论,杂志文章
doi:10.1016/j.bpj.2017.05.032
更新日期:2017-09-19 00:00:00
abstract::The hydrodynamic properties of rigid particles are calculated from models composed of spherical elements (beads) using theories developed by Kirkwood, Bloomfield, and their coworkers. Bead models have usually been built in such a way that the beads fill the volume occupied by the particles. Sometimes the beads are few...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(99)77457-6
更新日期:1999-06-01 00:00:00
abstract::The recently developed CMAP correction to the CHARMM22 force field (C22) is evaluated from 25 ns molecular dynamics simulations on hen lysozyme. Substantial deviations from experimental backbone root mean-square fluctuations and N-H NMR order parameters obtained in the C22 trajectories (especially in the loops) are el...
journal_title:Biophysical journal
pub_type: 信件
doi:10.1529/biophysj.105.078154
更新日期:2006-02-15 00:00:00