Differential stability of beta-sheets and alpha-helices in beta-lactamase: a high temperature molecular dynamics study of unfolding intermediates.

abstract：:We have explored the electromechanical properties of DNA on a nanometer-length scale using an electric field to force single molecules through synthetic nanopores in ultrathin silicon nitride membranes. At low electric fields, E < 200 mV/10 nm, we observed that single-stranded DNA can permeate pores with a diameter >/...

journal_title：Biophysical journal

authors： Heng JB,Aksimentiev A,Ho C,Marks P,Grinkova YV,Sligar S,Schulten K,Timp G

更新日期：2006-02-01 00:00:00

abstract：:We have examined the mechanisms underlying the voltage sensitivity of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptors in voltage-clamped outside-out patches and whole cells taken from the nucleus magnocellularis of the chick. Responses to either glutamate or kainate had outwardly rectifying current-volt...

journal_title：Biophysical journal

authors： Raman IM,Trussell LO

更新日期：1995-11-01 00:00:00

abstract：:To probe the complexity of the cell membrane organization and dynamics, it is important to obtain simple physical observables from experiments on live cells. Here we show that fluorescence correlation spectroscopy (FCS) measurements at different spatial scales enable distinguishing between different submicron confinem...

journal_title：Biophysical journal

authors： Wawrezinieck L,Rigneault H,Marguet D,Lenne PF

更新日期：2005-12-01 00:00:00

abstract：:Excised inside-out membrane patches are useful for studying the cGMP-activated ion channels that generate the electrical response to light in retinal rod cells. We show that strong ionic current across a patch changes the driving force on the current by altering the ionic concentration near the surface membrane, an ef...

journal_title：Biophysical journal

authors： Zimmerman AL,Karpen JW,Baylor DA

更新日期：1988-08-01 00:00:00

abstract：:The glucose transporters (GLUT/SLC2A) are members of the major facilitator superfamily. Here, we generated a three-dimensional model for Glut1 using a two-step strategy: 1), GlpT structure as an initial homology template and 2), evolutionary homology using glucose-6-phosphate translocase as a template. The resulting s...

journal_title：Biophysical journal

authors： Salas-Burgos A,Iserovich P,Zuniga F,Vera JC,Fischbarg J

更新日期：2004-11-01 00:00:00

abstract：:Theoretical studies of the electronic structure and spectra of models for the ferric resting state and Compound I intermediates of horseradish peroxidase (HRP-I) and catalase (CAT-I) have been performed using the INDO-RHF/CI method. The goals of these studies were twofold: i) to determine whether the axial ligand of H...

journal_title：Biophysical journal

authors： Du P,Loew GH

更新日期：1995-01-01 00:00:00

abstract：:The cellular cytoplasm is a complex, heterogeneous environment (both spatially and temporally) that exhibits viscoelastic behavior. To further develop our quantitative insight into cellular transport, we analyze data sets of mRNA molecules fluorescently labeled with MS2-GFP tracked in real time in live Escherichia col...

journal_title：Biophysical journal

authors： Lampo TJ,Stylianidou S,Backlund MP,Wiggins PA,Spakowitz AJ

更新日期：2017-02-07 00:00:00

abstract：:Various differential polarization images or Mueller images of model objects are generated using the equations derived in the previous paper (paper I of this series). These calculated images include models of the higher-order organization of metaphase chromosomes, and show the applicability of the differential polariza...

journal_title：Biophysical journal

authors： Kim M,Ulibarri L,Bustamante C

更新日期：1987-12-01 00:00:00

abstract：:Exchangeable apolipoproteins are located in the surface of lipoprotein particles and regulate lipid metabolism through direct protein-protein and protein-lipid interactions. These proteins are characterized by the presence of tandem repeats of amphiphatic alpha-helix segments and a high surface activity in monolayers ...

journal_title：Biophysical journal

authors： Bolanos-Garcia VM,Renault A,Beaufils S

更新日期：2008-03-01 00:00:00

abstract：:In this work, we present experimental data, supported by a quantitative model, on the generation and effect of potential gradients across a tethered bilayer lipid membrane (tBLM) with, to the best of our knowledge, novel architecture. A challenge to generating potential gradients across tBLMs arises from the tethering...

journal_title：Biophysical journal

authors： Cranfield CG,Cornell BA,Grage SL,Duckworth P,Carne S,Ulrich AS,Martinac B

更新日期：2014-01-07 00:00:00

abstract：:Kinesin and cytoplasmic dynein are microtubule-based motor proteins that actively transport material throughout the cell. Microtubules can intersect at a variety of angles both near the nucleus and at the cell periphery, and the behavior of molecular motors at these intersections has implications for long-range transp...

journal_title：Biophysical journal

authors： Ross JL,Shuman H,Holzbaur EL,Goldman YE

更新日期：2008-04-15 00:00:00

abstract：:Isolated sarcoplasmic reticulum (SR) vesicles with polymerized calcium pump protein were freeze-dried and rotary shadowed following uranyl acetate stabilization. This technique allows direct observation of a single side of the vesicle without requiring optical filtering. The heads of individual ATPase molecules, proje...

journal_title：Biophysical journal

authors： Ferguson DG,Franzini-Armstrong C,Castellani L,Hardwicke PM,Kenney LJ

更新日期：1985-10-01 00:00:00

abstract：:Intercellular channels formed of members of the gene family of connexins (Cxs) vary from being substantially cation selective to being anion selective. We took advantage of the ability of Cx46 to function as an unopposed hemichannel to examine the basis of Cx charge selectivity. Previously we showed Cx46 hemichannels ...

journal_title：Biophysical journal

authors： Trexler EB,Bukauskas FF,Kronengold J,Bargiello TA,Verselis VK

更新日期：2000-12-01 00:00:00

abstract：:The group-additive decomposition of the unfolding free energy of a protein in an osmolyte solution relative to that in water poses a fundamental paradox: whereas the decomposition describes the experimental results rather well, theory suggests that a group-additive decomposition of free energies is, in general, not va...

journal_title：Biophysical journal

authors： Tomar DS,Asthagiri D,Weber V

更新日期：2013-09-17 00:00:00

abstract：:Proteins are denatured in aqueous urea solution. The nature of the molecular driving forces has received substantial attention in the past, whereas the question how urea acts at different phases of unfolding is not yet well understood at the atomic level. In particular, it is unclear whether urea actively attacks fold...

journal_title：Biophysical journal

authors： Stumpe MC,Grubmüller H

更新日期：2009-05-06 00:00:00

abstract：:We have used confocal microscopy to examine the [Ca2+]i increase in the albino eggs of the frog Xenopus laevis after fertilization. Eggs were placed in agar wells with their animal poles downward so that fertilization occurred preferentially in the equatorial plane, and confocal microscopy was used to provide a two-di...

journal_title：Biophysical journal

authors： Fontanilla RA,Nuccitelli R

更新日期：1998-10-01 00:00:00

abstract：:Difference spectra between resting and excited nerve in the infrared region between 2000 and 1000 cm(-1) have been examined with a resolution of 0.5 cm(-1). Spectra were obtained with a modified Perkin-Elmer model 521 grating infrared spectrophotometer (Perkin-Elmer Corp., Instrument Div., Norwalk, Conn.), and the sig...

journal_title：Biophysical journal

authors： Sherebrin MH,MacClement BA,Franko AJ

更新日期：1972-08-01 00:00:00

abstract：:We have analyzed repellent signal processing in Escherichia coli by flash photorelease of leucine from photolabile precursors. We found that 1). response amplitudes of free-swimming cell populations increased with leucine jump concentration, with an apparent Hill coefficient of 1.3 and a half-maximal dose of 14.4 micr...

journal_title：Biophysical journal

authors： Khan S,Jain S,Reid GP,Trentham DR

更新日期：2004-06-01 00:00:00

abstract：:The M2 protein from the influenza A virus forms a proton channel in the virion that is essential for infection. This tetrameric protein appears to form a four-helix bundle spanning the viral membrane. Here the solid-state NMR method, 2D polarization inversion spin exchange at magic angle (PISEMA), has been used to obt...

journal_title：Biophysical journal

authors： Song Z,Kovacs FA,Wang J,Denny JK,Shekar SC,Quine JR,Cross TA

更新日期：2000-08-01 00:00:00

abstract：:The elastic properties of cylindrical segments of sarcolemma were studied in single striated fibers of the frog semitendinosus muscle. All measurements were made on membranes of retraction zones, cell segments from which the sarcoplasm had retracted. Quantitative morphological studies indicated that three deforming fo...

journal_title：Biophysical journal

authors： Fields RW

更新日期：1970-05-01 00:00:00

abstract：:Myosin subfragment 1 (S1) can be specifically modified at Lys-553 with the fluorescent probe FHS (6-[fluorescein-5(and 6)-carboxamido]hexanoic acid succinimidyl ester) (Bertrand, R., J. Derancourt, and R. Kassab. 1995. Biochemistry. 34:9500-9507), and solvent quenching of FHS-S1 with iodide has been shown to be sensit...

journal_title：Biophysical journal

authors： Cooper WC,Chrin LR,Berger CL

更新日期：2000-03-01 00:00:00

abstract：:Multiplex hybridization reactions of perfectly matched duplexes and duplexes containing a single basepair mismatch (SNPs) were investigated on DNA microarrays. Effects of duplex length, G-C percentage, and relative position of the SNP on duplex hybridization and SNP resolution were determined. Our theoretical model of...

journal_title：Biophysical journal

authors： Fish DJ,Horne MT,Searles RP,Brewood GP,Benight AS

更新日期：2007-05-15 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

authors： Tichauer RH,Favre G,Cabantous S,Landa G,Hemeryck A,Brut M

更新日期：2018-10-16 00:00:00

abstract：:Chinese hamster ovary cells were irradiated with 100-5,000 rads of X-rays and inhibition of the initiation of replicons after irradiation was demonstrated by analyzing nascent DNA sedimented in alkaline sucrose gradients. The renaturation kinetics of DNA synthesized during 60 min of incubation after irradiation was co...

journal_title：Biophysical journal

authors： Mattern MR,Painter RB

更新日期：1977-08-01 00:00:00

abstract：:The effect of Ca ion concentration on cross-bridge kinetics in a small bundle (one to three fibers) of chemically skinned rabbit psoas muscle is studied. The length of the muscle is oscillated in small amplitude sine waves (0.2% L0 peak-to-peak) at varying frequencies (0.125 -- 167 Hz), and the resulting amplitude and...

journal_title：Biophysical journal

authors： Kawai M,Cox RN,Brandt PW

更新日期：1981-08-01 00:00:00

abstract：:Microsecond rotational motions of nitroxide spin labels are measured primarily with saturation transfer electron paramagnetic resonance (ST-EPR). In the present study we have used model system experiments to quantitatively evaluate different ST-EPR spectral parameters, both in-phase and out-of-phase, with an emphasis ...

journal_title：Biophysical journal

authors： Squier TC,Thomas DD

更新日期：1986-04-01 00:00:00

abstract：:Equatorial x-ray diffraction patterns were obtained from single skinned rabbit psoas fibers during various degrees of activation under isometric conditions at ionic strength 170 mM and 6-9 degrees C. By direct calcium activation, contraction was homogeneous throughout the preparation, and by using a cycling technique ...

journal_title：Biophysical journal

authors： Brenner B,Yu LC

更新日期：1985-11-01 00:00:00

abstract：:Based on the existence of ATP-sensitive potassium channels in the plasma membrane of pancreatic beta cells, we develop a quantitative explanation of the electrical activity observed in pancreatic islets. The proposed mechanism involves the voltage-dependent inward calcium and outward potassium currents described by Ro...

journal_title：Biophysical journal

authors： Keizer J,Magnus G

更新日期：1989-08-01 00:00:00

abstract：:When a dissolved macromolecule is in chemical equilibrium with a free ionic species, the charge configuration, and hence the dipole vector, of the macromolecule is fluctuating. Expressions for the static dielectric constant and the relaxation spectrum of such a mixture are here derived in terms of the components of th...

journal_title：Biophysical journal

authors： Scheider W

更新日期：1965-09-01 00:00:00

abstract：:Although RNase Y acts as the key enzyme initiating messenger RNA decay in Bacillus subtilis and likely in many other Gram-positive bacteria, its three-dimensional structure remains unknown. An antibody belonging to the rare immunoglobulin G (IgG) 2b λx isotype was raised against a 12-residue conserved peptide from the...

journal_title：Biophysical journal

authors： Hardouin P,Velours C,Bou-Nader C,Assrir N,Laalami S,Putzer H,Durand D,Golinelli-Pimpaneau B

更新日期：2018-12-04 00:00:00