Abstract:
:We explore the means by which immobilization of a substrate on a surface can increase the rate of a diffusion-controlled enzymatic reaction. A quasichemical approach is developed and compared with Brownian dynamics simulations. We use these methods to show that restricting only the orientation of the enzyme by long-range interactions with the surface is sufficient for enhancing catalysis.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Nag A,Dinner ARdoi
10.1529/biophysj.105.072785subject
Has Abstractpub_date
2006-02-01 00:00:00pages
896-902issue
3eissn
0006-3495issn
1542-0086pii
S0006-3495(06)72277-9journal_volume
90pub_type
杂志文章abstract::Impact loading of articular cartilage causes extensive chondrocyte death. Cell membranes have a limited elastic range of 3-4% strain but are protected from direct stretch during physiological loading by their membrane reservoir, an intricate pattern of membrane folds. Using a finite-element model, we suggested previou...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2013.08.035
更新日期:2013-10-01 00:00:00
abstract::Reversible blockage of the voltage-dependent anion channel (VDAC) of the mitochondrial outer membrane by dimeric tubulin is being recognized as a potent regulator of mitochondrial respiration. The tubulin-blocked state of VDAC is impermeant for ATP but only partially closed for small ions. This residual conductance al...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.03.058
更新日期:2012-05-02 00:00:00
abstract::The kinetic properties of the three taxonomic A substates of sperm whale carbonmonoxy myoglobin in 75% glycerol/buffer are studied by flash photolysis with monitoring in the infrared stretch bands of bound CO at nu(A0) approximately 1967 cm-1, nu(A1) approximately 1947 cm-1, and nu(A3) approximately 1929 cm-1 between ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79359-1
更新日期:1996-09-01 00:00:00
abstract::The temperature dependence of drug blockade of a calcium-dependent potassium channel K(Ca) has been studied in cultured CA1 hippocampal neurons. Channel openings from a 70-pS K+ channel were recorded when inside-out patches were exposed to a bath solution containing 140 mM K+ and 0.2 mM Ca2+. The mean open times of ch...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(91)82161-0
更新日期:1991-11-01 00:00:00
abstract::We present MEMLET (MATLAB-enabled maximum-likelihood estimation tool), a simple-to-use and powerful program for utilizing maximum-likelihood estimation (MLE) for parameter estimation from data produced by single-molecule and other biophysical experiments. The program is written in MATLAB and includes a graphical user ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.06.019
更新日期:2016-07-26 00:00:00
abstract::Quasilongitudinal sound velocities and the second-order elastic moduli of tetragonal hen egg-white lysozyme crystals were determined as a function of relative humidity (RH) by Brillouin scattering. In hydrated crystals the measured sound velocities in the [110] plane vary between 2.12 +/- 0.03 km/s along the [001] dir...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74738-9
更新日期:2003-11-01 00:00:00
abstract::Integrin-mediated signaling is crucial for cell-substrate adhesion and can be triggered from both intra- and extracellular interactions. Although talin binding is sufficient for inside-out activation of integrin, other cytoplasmic proteins such as α-actinin and filamin can directly interfere with talin-mediated integr...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2017.06.064
更新日期:2017-08-22 00:00:00
abstract::The characteristic equatorial X-ray pattern from a relaxed vertebrate skeletal muscle changes when the muscle is activated. In particular, there is a simultaneous decrease in the intensity of the first reflection (I10) and increase in the intensity of the second (I11). This observed change is almost reciprocal. When c...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(78)85510-6
更新日期:1978-01-01 00:00:00
abstract::Eukaryotic genomes are hierarchically organized into protein-DNA assemblies for compaction into the nucleus. Nucleosomes, with the (H3-H4)2 tetrasome as a likely intermediate, are highly dynamic in nature by way of several different mechanisms. We have recently shown that tetrasomes spontaneously change the direction ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2019.07.055
更新日期:2019-12-03 00:00:00
abstract::Conditions for which a ligand reversibly bound to a cell surface dissociates and then rebinds to the surface have been theoretically examined. The coupled differential equations that describe reaction at the interface between sites on a plane and three-dimensional solution have been described previously (Thompson, N. ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)77836-1
更新日期:1998-03-01 00:00:00
abstract::We have used chemical synthesis, electron paramagnetic resonance (EPR), and circular dichroism to detect and analyze the structural dynamics of a ryanodine receptor (RyR) peptide bound to calmodulin (CaM). The skeletal muscle calcium release channel RyR1 is activated by Ca2+-free CaM and inhibited by Ca2+-bound CaM. T...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.10.025
更新日期:2016-12-06 00:00:00
abstract::A new flow configuration allows a flow cytometer of high resolution and stability to be assembled from an inverted fluorescence microscope with incident illumination, a pulse photometer, and a multichannel pulse height analyzer. A nozzle produces a hydrodynamically focused sample stream in a liquid jet that id directe...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(79)85157-7
更新日期:1979-10-01 00:00:00
abstract::The effects of myosin regulatory light chain (RLC) phosphorylation and strain on adenosine diphosphate (ADP) release from cross-bridges in phasic (rabbit bladder (Rbl)) and tonic (femoral artery (Rfa)) smooth muscle were determined by monitoring fluorescence transients of the novel ADP analog, 3'-deac-eda-ADP (deac-ed...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(04)74289-7
更新日期:2004-04-01 00:00:00
abstract::This paper describes a framework model for proton conduction through gramicidin; a model designed to incorporate information from molecular dynamics and use this to predict conductance properties. The state diagram describes both motion of an excess proton within the pore as well as the reorientation of waters within ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)75992-9
更新日期:2001-01-01 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::Cell adhesion to the extracellular matrix (ECM) is highly active and plays a crucial role in various physiological functions. The active response of cells to physicochemical cues has been universally discovered in multiple microenvironments. However, the mechanisms to rule these active behaviors of cells are still poo...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2020.04.016
更新日期:2020-06-02 00:00:00
abstract::We have used fluorescence-quenching measurements to characterize the partitioning of a variety of indolyl-labeled phospho- and sphingolipids between gel or liquid-ordered and liquid-disordered lipid domains in several types of lipid bilayers where such domains coexist. In both cholesterol-free and cholesterol-containi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74857-7
更新日期:2003-01-01 00:00:00
abstract::We have examined the distribution of ryanodine receptors, L-type Ca(2+) channels, calsequestrin, Na(+)/Ca(2+) exchangers, and voltage-gated Na(+) channels in adult rat ventricular myocytes. Enzymatically dissociated cells were fixed and dual-labeled with specific antibodies using standard immunocytochemistry protocols...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76506-4
更新日期:2000-11-01 00:00:00
abstract::The tunneling transfer of electrons between two sites, appropriate to biological intermolecular electron transfer, contains physical considerations which are not important in the tunneling transfer between two metals. Analyses (such as the recent one by Hales) based on the well-known formula for the latter but applied...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(76)85769-4
更新日期:1976-10-01 00:00:00
abstract::Hint2, one of the five members of the superfamily of the histidine triad AMP-lysine hydrolase proteins, is expressed in mitochondria of various cell types. In human adrenocarcinoma cells, Hint2 modulates Ca(2+) handling by mitochondria. As Hint2 is highly expressed in hepatocytes, we investigated if this protein affec...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2013.06.048
更新日期:2013-09-03 00:00:00
abstract::Purple photosynthetic bacteria harvest light using pigment-protein complexes which are often arranged in pseudo-organelles called chromatophores. A model of a chromatophore from Rhodospirillum photometricum was constructed based on atomic force microscopy data. Molecular-dynamics simulations and quantum-dynamics calcu...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.04.030
更新日期:2014-06-03 00:00:00
abstract::NMR and CD studies have been used to analyze the model membrane-bound structure of the neuropeptide substance P (RPKPQQFFGLM-NH2, SP), which has previously been proposed as the NK1 receptor active form. Conformations were determined for the SP in the presence of aqueous solutions of zwitterionic dodecylphosphocholine ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79734-5
更新日期:1996-04-01 00:00:00
abstract::The space-clamped squid axon membrane and two versions of the Hodgkin-Huxley model (the original, and a strongly adapting version) are subjected to a first order dynamic analysis. Stable, repetitive firing is induced by phase-locking nerve impulses to sinusoidal currents. The entrained impulses are then pulse position...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(80)85078-8
更新日期:1980-04-01 00:00:00
abstract::We introduce dual-color time-integrated fluorescence cumulant analysis (TIFCA) to analyze fluorescence fluctuation spectroscopy data. Dual-color TIFCA utilizes the bivariate cumulants of the integrated fluorescent intensity from two detection channels to extract the brightness in each channel, the occupation number, a...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.086181
更新日期:2006-10-01 00:00:00
abstract::Human posttranslationally modified N-ras oncogenes are known to be implicated in numerous human cancers. Here, we applied a combination of experimental and computational techniques to determine structural and dynamical details of the lipid chain modifications of an N-ras heptapeptide in 1,2-dimyristoyl-sn-glycero-3-ph...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.104562
更新日期:2007-10-15 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::The effect of a nonuniform solute concentration on the osmotic transport of water through the boundaries of a simple model cell is investigated. A system of two ordinary differential equations is derived for the motion of a single cell in the limit of a fast solute diffusion, and an analytic solution is obtained for o...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(99)76977-8
更新日期:1999-09-01 00:00:00
abstract::Titin is a very large (>3 MDa) protein found in striated muscle where it is believed to participate in myogenesis and passive tension. A prominent feature in the A-band portion of titin is the presence of an 11-domain super-repeat of immunoglobulin superfamily and fibronectin-type-III-like domains. Seven overlapping c...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/s0006-3495(01)75811-0
更新日期:2001-09-01 00:00:00
abstract::Fluorescence correlation spectroscopy (FCS) is a sensitive and widely used technique for measuring diffusion. FCS data are conventionally modeled with a finite number of diffusing components and fit with a least-square fitting algorithm. This approach is inadequate for analyzing data obtained from highly heterogeneous...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)75006-1
更新日期:2003-03-01 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