Osmotic and pH transmembrane gradients control the lytic power of melittin.

abstract：:Critical to biological processes such as secretion and transport, protein-lipid interactions within the membrane and at the membrane-water interface still raise many questions. Here we examine the role of lipid headgroups in these interactions by using gramicidin A (gA) channels in planar bilayers as a probe. We show ...

journal_title：Biophysical journal

authors： Rostovtseva TK,Petrache HI,Kazemi N,Hassanzadeh E,Bezrukov SM

更新日期：2008-02-15 00:00:00

abstract：:Binding features of heroin in whole blood and in blood fractions were delineated by measuring the selective spin-lattice relaxation rates of heroin protons in physiologic conditions. Interaction with some receptor located in the whole human blood or in the human plasma was detected and the apparent binding constant ca...

journal_title：Biophysical journal

authors： Barni Comparini I,Gaggelli E,Marchettini N,Valensin G

更新日期：1985-08-01 00:00:00

abstract：:Unlike most transmembrane proteins, phospholipids can migrate from one leaflet of the membrane to the other. Because this spontaneous lipid translocation (flip-flop) tends to be very slow, cells facilitate the process with enzymes that catalyze the transmembrane movement and thereby regulate the transbilayer lipid dis...

journal_title：Biophysical journal

authors： Doktorova M,Heberle FA,Marquardt D,Rusinova R,Sanford RL,Peyear TA,Katsaras J,Feigenson GW,Weinstein H,Andersen OS

更新日期：2019-03-05 00:00:00

abstract：:We have obtained new insights into the behavior of a class of excitable systems when a stimulus, or parameter, is slowly tuned through a threshold value. Such systems do not accommodate no matter how slowly a stimulus ramp is applied, and the stimulus value at onset of repetitive activity shows a curious, nonmonotonic...

journal_title：Biophysical journal

authors： Rinzel J,Baer SM

更新日期：1988-09-01 00:00:00

abstract：:Association of transmembrane (TM) helices is facilitated by the close packing of small residues present along the amino-acid sequence. Extensive studies have established the role of such small residue motifs (GxxxG) in the dimerization of Glycophorin A (GpA) and helped to elucidate the association of TM domains in the...

journal_title：Biophysical journal

authors： Prakash A,Janosi L,Doxastakis M

更新日期：2010-12-01 00:00:00

abstract：:Mechanosensitive ion channels (MSCs) which could provide for fast osmoregulatory responses in bacteria, remain unidentified as molecular entities. MSCs from Escherichia coli (strain AW740) were examined using the patch-clamp technique, either (a) in giant spheroplasts, (b) after reconstitution by fusing native membran...

journal_title：Biophysical journal

authors： Sukharev SI,Martinac B,Arshavsky VY,Kung C

更新日期：1993-07-01 00:00:00

abstract：:Polarized Fourier transform infrared spectroscopy has been used to study the structure of purple membrane from Halobacterium halobium. Membranes were oriented by drying a suspension of membrane fragments onto Irtran-4 slides. Dichroism measurements of the amide I, II and A peaks were used to find the average spatial o...

journal_title：Biophysical journal

authors： Rothschild KJ,Clark NA

更新日期：1979-03-01 00:00:00

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...

journal_title：Biophysical journal

authors： Bullen A,Patel SS,Saggau P

更新日期：1997-07-01 00:00:00

abstract：:A dynamic model of smooth muscle contraction is presented and is compared with the mechanical properties of vascular smooth muscle in the rat portal vein. The model is based on the sliding filament theory and the assumption that force is produced by cross-bridges extending from the myosin to the actin filaments. Thus,...

journal_title：Biophysical journal

authors： Gestrelius S,Borgström P

更新日期：1986-07-01 00:00:00

abstract：:Intracellular Ca2+ was determined with the fura-2 technique during electrically induced contractions in the rabbit rectococcygeus smooth muscle at 22 degreesC. The muscles were electrically activated to give short, reproducible contractions. Intracellular [Ca2+] increased during activation; the increase in [Ca2+] prec...

journal_title：Biophysical journal

authors： Arner A,Malmqvist U,Rigler R

更新日期：1998-10-01 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

authors： Gupta VK,Neeves KB,Eggleton CD

更新日期：2012-07-03 00:00:00

abstract：:A new approach to the calculation of bimolecular association constants for partially diffusion-limited reactions between asymmetric species (e.g. the ligand binding site of a macromolecule covers only a portion of its surface) is presented. The usual formulation, which is almost always analytically intractable, is bas...

journal_title：Biophysical journal

authors： Shoup D,Lipari G,Szabo A

更新日期：1981-12-01 00:00:00

abstract：:Efficient and rapid immune response upon challenge by an infectious agent is vital to host defense. The encounter of leukocytes (white blood cells of the immune system) with their targets is the first step in this response. Analysis of the kinetics of this process is essential not only to understanding dynamic behavio...

journal_title：Biophysical journal

authors： Charnick SB,Lauffenburger DA

更新日期：1990-05-01 00:00:00

abstract：:Human apolipoprotein E (apoE) is a 299-amino-acid protein with a molecular weight of 34 kDa. The difference between the apoE3 and apoE4 isoforms is a single residue substitution involving a Cys-Arg replacement at residue 112. ApoE4 is positively associated with atherosclerosis and late-onset and sporadic Alzheimer's d...

journal_title：Biophysical journal

authors： Chou CY,Lin YL,Huang YC,Sheu SY,Lin TH,Tsay HJ,Chang GG,Shiao MS

更新日期：2005-01-01 00:00:00

abstract：:Clusters of calcium-loaded sarcoplasmic reticulum (SR) vesicles in agarose gel were previously shown to behave as an excitable medium that propagates calcium waves. In a 3D-hexagonal disposition, the distance between neighboring spheres (which may stand for SR vesicles) is constant and the relationship between distanc...

journal_title：Biophysical journal

authors： Wussling MH,Aurich I,Knauf O,Podhaisky H,Holzhausen HJ

更新日期：2004-12-01 00:00:00

abstract：:Certain standard properties, including spontaneous curvature, are assumed for the membrane of a bilipid vesicle. Then, if there is a mechanism that causes the membrane area to increase, vesicle cleavage is found to occur. ...

journal_title：Biophysical journal

authors： Luke JC,Kaplan JI

更新日期：1979-01-01 00:00:00

abstract：:Sharing of positive or negative regulators between multiple targets is frequently observed in cellular signaling cascades. For instance, phosphatase sharing between multiple kinases is ubiquitous within the MAPK pathway. Here we investigate how such phosphatase sharing could shape robustness and evolvability of the ph...

journal_title：Biophysical journal

authors： Ghosh B,Sarma U,Sourjik V,Legewie S

更新日期：2018-01-09 00:00:00

abstract：:Photosystem II catalyzes photosynthetic water oxidation in plants, green algae, and cyanobacteria. The manganese-containing active site cycles through a series of five oxidation states, S(n), where n refers to the number of oxidizing equivalents stored. In this report, reaction-induced Fourier transform infrared and e...

journal_title：Biophysical journal

authors： Halverson KM,Barry BA

更新日期：2003-10-01 00:00:00

abstract：:The extracellular space of the brain is the heterogeneous porous medium formed by the spaces between the brain cells. Diffusion in this interstitial space is the mechanism by which glucose and oxygen are delivered to the brain cells from the vascular system. It is also a medium for the transport of certain information...

journal_title：Biophysical journal

authors： Nandigam RK,Kroll DM

更新日期：2007-05-15 00:00:00

abstract：:We developed a model of the rat ventricular myocyte at room temperature to predict the relative effects of different mechanisms on the cause of the slow increase in force in response to a step change in muscle length. We performed simulations in the presence of stretch-dependent increases in flux through the Na(+)-H(+...

journal_title：Biophysical journal

authors： Niederer SA,Smith NP

更新日期：2007-06-01 00:00:00

abstract：:A free radical probe was introduced into single barnacle muscle cells, and its freedom of motion inferred from the spin resonance spectra. The probe reported an average local viscosity of 5-10 cp compared with 1 cp for pure water. From a comparison of the temperature dependence of the probe's tumbling rate in model aq...

journal_title：Biophysical journal

authors： Sachs F,Latorre R

更新日期：1974-04-01 00:00:00

abstract：:Infrared spectroscopy has long been used to examine the average secondary structure and orientation of membrane proteins. With the recent utilization of site-specific isotope labeling (e.g., peptidic 1-(13)C = (18)O) it is now possible to examine localized properties, rather than global averages. The technique of site...

journal_title：Biophysical journal

authors： Arbely E,Kass I,Arkin IT

更新日期：2003-10-01 00:00:00

abstract：:In a cell-populated collagen gel, intrinsic fiber structure visible in differential interference contrast images can provide markers for an in situ strain gauge to quantify cell-gel mechanics, while optical sections of fluorescent protein distribution capture cytoskeletal kinematics. Mechanics quantification can be de...

journal_title：Biophysical journal

authors： Vanni S,Lagerholm BC,Otey C,Taylor DL,Lanni F

更新日期：2003-04-01 00:00:00

abstract：:To investigate the force generation properties of Chlamydomonas axonemal inner-arm dyneins in response to external force, we analyzed microtubule gliding on dynein-coated surfaces under shear flow. When inner-arm dynein c was used, microtubule translocation in the downstream direction accelerated with increasing flow ...

journal_title：Biophysical journal

authors： Kikushima K,Kamiya R

更新日期：2009-09-16 00:00:00

abstract：:The mechanisms by which the mammalian mitotic spindle is guided to a predefined orientation through microtubule-cortex interactions have recently received considerable interest, but there has been no dynamic model that describes spindle movements toward the preferred axis in human cells. Here, we develop a dynamic mod...

journal_title：Biophysical journal

authors： Corrigan AM,Shrestha R,Draviam VM,Donald AM

更新日期：2015-10-06 00:00:00

abstract：:The interaction between actin and myosin in the filament array of glycerinated muscle fibers has been monitored using paramagnetic probes and mechanical measurements. Both fiber stiffness and the spectra of probes bound to a reactive sulfydral on the myosin head were measured as the actomyosin bond was weakened by add...

journal_title：Biophysical journal

authors： Pate E,Cooke R

更新日期：1988-04-01 00:00:00

abstract：:Voltage-sensitive fluorescent dyes are commonly used to measure cardiac electrical activity. Recent studies indicate, however, that optical action potentials (OAPs) recorded from the myocardial surface originate from a widely distributed volume beneath the surface and may contain useful information regarding intramura...

journal_title：Biophysical journal

authors： Hyatt CJ,Mironov SF,Wellner M,Berenfeld O,Popp AK,Weitz DA,Jalife J,Pertsov AM

更新日期：2003-10-01 00:00:00

abstract：:The Green's function technique is applied to a study of breathing modes in a DNA double helix which contains a region of different base pairs from the rest of the double helix. The calculation is performed on a G-C helix in the B conformation with four consecutive base pairs replaced by A-T. The average stretch in hyd...

journal_title：Biophysical journal

authors： Feng Y,Prohofsky EW

更新日期：1990-03-01 00:00:00

abstract：:The effects of chemical modifications of myosin's reactive cysteines on actomyosin adenosine triphosphatase (ATPase) activities and sliding velocities in the in vitro motility assays were examined in this work. The three types of modifications studied were 4-[N-[(iodoacetoxy)ethyl]-N-methylamino]-7-nitrobenz-2-oxa-1,3...

journal_title：Biophysical journal

authors： Root DD,Reisler E

更新日期：1992-09-01 00:00:00

abstract：:Low frequency audible vibrations are produced by human skeletal muscles undergoing sustained contraction. The effect is easily demonstrable with an electronic stethoscope which amplifies sound below 50 Hz. Autocorrelation analysis of the signal shows that it is periodic with a frequency 25 +/- 2.5 Hz. The quality of t...

journal_title：Biophysical journal

authors： Oster G,Jaffe JS

更新日期：1980-04-01 00:00:00