Poly-L-glutamine forms cation channels: relevance to the pathogenesis of the polyglutamine diseases.

abstract：:Myxicola giant axons internally injected with tetraethylammonium chloride to block potassium currents were examined under voltage clamp. The sodium inactivation time constants obtained from the decline in INa during step depolarizations were substantially smaller than those obtained using conditioning prepulses to the...

journal_title：Biophysical journal

authors： Schauf CL,Pencek TL,Davis FA

更新日期：1976-09-01 00:00:00

abstract：:The neutral anesthetics chloroform and benzyl alcohol, at concentrations that block the nerve impulse, greatly modify the transport parameters of positive and negative ions in lipid bilayers made from monolayers. Both chloroform and benzyl alcohol increase the membrane permeability to these ions and increase the trans...

journal_title：Biophysical journal

authors： Reyes J,Latorre R

更新日期：1979-11-01 00:00:00

abstract：:The Mie theory of scattering is used to provide new information on how changes in particle volume, with no change in dry weight, should influence light scattering for various scattering angles and particle sizes. Many biological cells (e.g., algal cells, erythrocytes) and large subcellular structures (e.g., chloroplas...

journal_title：Biophysical journal

authors： Latimer P,Pyle BE

更新日期：1972-07-01 00:00:00

abstract：:A long-standing question about membrane structure and function is the degree to which the physical properties of the inner and outer leaflets of a bilayer are coupled to one another. Using our recently developed methods to prepare asymmetric vesicles, coupling was investigated for vesicles containing phosphatidylcholi...

journal_title：Biophysical journal

authors： Chiantia S,London E

更新日期：2012-12-05 00:00:00

abstract：:Molecular dynamics simulations of the tripeptide Ala-Phe-Ala-O-tert-butyl interacting with dimyristoylphosphatidylcholine lipid bilayers have been carried out. The lipid and aqueous environments of the peptide, the alkyl chain order, and the lipid and peptide dynamics have been investigated with use of density profile...

journal_title：Biophysical journal

authors： Damodaran KV,Merz KM Jr,Gaber BP

更新日期：1995-10-01 00:00:00

abstract：:The adsorption of hydrophobic ions such as tetraphenylborate to thin lipid membranes is known to saturate at approximately 0.1 ion/(nm)2. This saturation can be quantitatively explained by electrostatic repulsion between the ions if they are treated as discrete, mobile particles that adsorb within the lipid at least p...

journal_title：Biophysical journal

authors： Tsien RY,Hladky SB

更新日期：1982-07-01 00:00:00

abstract：:Collagen fibrils play an important role in the human body, providing tensile strength to connective tissues. These fibrils are characterized by a banding pattern with a D-period of 67 nm. The proposed origin of the D-period is the internal staggering of tropocollagen molecules within the fibril, leading to gap and ove...

journal_title：Biophysical journal

authors： Baldwin SJ,Quigley AS,Clegg C,Kreplak L

更新日期：2014-10-21 00:00:00

abstract：:Fusion of lipid bilayers proceeds via a sequence of distinct structural transformations. Its early stage involves a localized, hemifused intermediate in which the proximal but not yet the distal monolayers are connected. Whereas the so-called stalk model most successfully accounts for the properties of the hemifused i...

journal_title：Biophysical journal

authors： May S

更新日期：2002-12-01 00:00:00

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：:We have studied the low-resolution solution conformation of a Holliday (or four-way) DNA junction by using small-angle x-ray scattering, sedimentation velocity, and computational modeling techniques. The scattering data were analyzed in two independent ways: firstly, by rigid-body modeling of the scattering data using...

journal_title：Biophysical journal

authors： Nöllmann M,Stark WM,Byron O

更新日期：2004-05-01 00:00:00

abstract：:Amantadine is known to block the M2 proton channel of the Influenza A virus. Here, we present a structure of the M2 trans-membrane domain blocked with amantadine, built using orientational constraints obtained from solid-state NMR polarization-inversion-spin-exchange-at-the-magic-angle experiments. The data indicates ...

journal_title：Biophysical journal

authors： Hu J,Asbury T,Achuthan S,Li C,Bertram R,Quine JR,Fu R,Cross TA

更新日期：2007-06-15 00:00:00

abstract：:Kinesin is a motor protein that uses the energy derived from the hydrolysis of ATP to power the transport of organelles along microtubules. To probe the mechanism of this chemical-to-mechanical energy transduction reaction, the movement of microtubules across glass surfaces coated with kinesin was perturbed by raising...

journal_title：Biophysical journal

authors： Hunt AJ,Gittes F,Howard J

更新日期：1994-08-01 00:00:00

abstract：:During postnatal development, major changes in mechanical properties of skeletal muscle occur. We investigated passive properties of skeletal muscle in mice and rabbits that varied in age from 1 day to approximately 1 year. Neonatal skeletal muscle expressed large titin isoforms directly after birth, followed by a gra...

journal_title：Biophysical journal

authors： Ottenheijm CA,Knottnerus AM,Buck D,Luo X,Greer K,Hoying A,Labeit S,Granzier H

更新日期：2009-10-21 00:00:00

abstract：:Atomic force microscopy (AFM) is used to study mechanical properties of biological materials at submicron length scales. However, such samples are often structurally heterogeneous even at the local level, with different regions having distinct mechanical properties. Physical or chemical disruption can isolate individu...

journal_title：Biophysical journal

authors： Lee JJ,Rao S,Kaushik G,Azeloglu EU,Costa KD

更新日期：2018-06-05 00:00:00

abstract：:Here we present a model for maltodextrin translocation through maltoporin channels. In a first step, our theoretical analysis does consider the case of a single binding site for a given substrate in a structurally unaffected channel with a possibly different entrance barrier on either side. It is shown how by means of...

journal_title：Biophysical journal

authors： Schwarz G,Danelon C,Winterhalter M

更新日期：2003-05-01 00:00:00

abstract：:In permeabilized single fibers of fast (psoas) and slow (soleus) muscle from the rabbit, the effect of pH on isometric myofibrillar ATPase activity and force was studied at 15 degrees C, in the pH range 6.4-7.9. ATPase activity was measured photometrically by enzymatic coupling of the regeneration of ATP to the oxidat...

journal_title：Biophysical journal

authors： Potma EJ,van Graas IA,Stienen GJ

更新日期：1994-12-01 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

authors： Wang TY,Silvius JR

更新日期：2003-01-01 00:00:00

abstract：:Most of the decisive molecular events in biology take place at the protein-water interface. The dynamical properties of the hydration layer are therefore of fundamental importance. To characterize the dynamical heterogeneity and rotational activation energy in the hydration layer, we measured the (17)O spin relaxation...

journal_title：Biophysical journal

authors： Mattea C,Qvist J,Halle B

更新日期：2008-09-15 00:00:00

abstract：:The two-microelectrode, voltage-clamp technique was applied to rabbit cardiac Purkinje fibers to study the interaction of tetrodotoxin (TTX) with the slowly inactivating Na current. Binding of TTX to rested, inactivated, and activated channels was estimated by measuring the relative decrease of current at the beginnin...

journal_title：Biophysical journal

authors： Carmeliet E

更新日期：1987-01-01 00:00:00

abstract：:Studies in Shaker, a voltage-dependent potassium channel, suggest a coupling between activation and inactivation. This coupling is controversial in hERG, a fast-inactivating voltage-dependent potassium channel. To address this question, we transferred to hERG the S3-S4 linker of the voltage-independent channel, rolf, ...

journal_title：Biophysical journal

authors： Choveau FS,El Harchi A,Rodriguez N,Louérat-Oriou B,Baró I,Demolombe S,Charpentier F,Loussouarn G

更新日期：2009-09-02 00:00:00

abstract：:Calmodulin (CaM) expression is upregulated upon HIV-1 infection and interacts with proteins involved in viral processing, including the multifunctional HIV-1 MA protein. We present here the results of studies utilizing small-angle neutron scattering with contrast variation that, when considered in the light of earlier...

journal_title：Biophysical journal

authors： Taylor JE,Chow JYH,Jeffries CM,Kwan AH,Duff AP,Hamilton WA,Trewhella J

更新日期：2012-08-08 00:00:00

abstract：:The energy transfer and charge separation kinetics of a photosystem I (PS I) core particle of an antenna size of 100 chlorophyll/P700 has been studied by combined fluorescence and transient absorption kinetics with picosecond resolution. This is the first combined picosecond study of transient absorption and fluoresce...

journal_title：Biophysical journal

authors： Holzwarth AR,Schatz G,Brock H,Bittersmann E

更新日期：1993-06-01 00:00:00

abstract：:Thermodynamically rigorous free energy methods in principle allow the exact computation of binding free energies in biological systems. Here, we use thermodynamic integration together with molecular dynamics simulations of a DNA-protein complex to compute relative binding free energies of a series of mutants of a prot...

journal_title：Biophysical journal

authors： Beierlein FR,Kneale GG,Clark T

更新日期：2011-09-07 00:00:00

abstract：:We measured the viscoelastic properties of the cytoplasm of J774 macrophages with a recently developed microrheometer. Ferromagnetic beads (1.3 microm in diameter) were used to determine the local viscoelastic moduli. Step-force pulses were applied to the magnetic beads and the displacement was observed by single part...

journal_title：Biophysical journal

authors： Bausch AR,Möller W,Sackmann E

更新日期：1999-01-01 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：:An alternative theoretical approach to enzyme kinetics that is particularly applicable to single-molecule enzymology is presented. The theory, originated by Van Slyke and Cullen in 1914, develops enzyme kinetics from a "time perspective" rather than the traditional "rate perspective" and emphasizes the nonequilibrium ...

journal_title：Biophysical journal

authors： Qian H

更新日期：2008-07-01 00:00:00

abstract：:KATP channels assemble from four regulatory SUR1 and four pore-forming Kir6.2 subunits. At the single-channel current level, ATP-dependent gating transitions between the active burst and the inactive interburst conformations underlie inhibition of the KATP channel by intracellular ATP. Previously, we identified a slow...

journal_title：Biophysical journal

authors： Drain P,Geng X,Li L

更新日期：2004-04-01 00:00:00

abstract：:Freeze-fracture electron micrographs from degranulating cells show that the lumen of the secretory granule is connected to the extracellular compartment via large (20 to 150 nm diameter) aqueous pores. These exocytotic fusion pores appear to be made up of a highly curved bilayer that spans the plasma and granule membr...

journal_title：Biophysical journal

authors： Nanavati C,Markin VS,Oberhauser AF,Fernandez JM

更新日期：1992-10-01 00:00:00

abstract：:Hormones are released from neuroendocrine cells by passing through an exocytotic pore that forms after vesicle and plasma membrane fusion. An elegant way to study this process at the single-vesicle level is to use styryl dyes, which stain not only the membrane, but also the matrix of individual vesicles in some neuroe...

journal_title：Biophysical journal

authors： Stenovec M,Poberaj I,Kreft M,Zorec R

更新日期：2005-04-01 00:00:00

abstract：:We describe two enhancements of the planar bilayer recording method which enable low-noise recordings of single-channel currents activated by voltage steps in planar bilayers formed on apertures in partitions separating two open chambers. First, we have refined a simple and effective procedure for making small bilayer...

journal_title：Biophysical journal

authors： Wonderlin WF,Finkel A,French RJ

更新日期：1990-08-01 00:00:00