Abstract:
:The nuclear magnetic resonance (NMR) of water protons in live and glycerinated muscle, suspensions of glycerinated myofibrils, and solutions of several muscle proteins has been studied. T(1) and T(2), measured on partially hydrated proteins by pulsed spin-echo techniques, decreased as the ratio of water to protein decreased, showing that the water which is tightly bound by the protein has short relaxation times. In live muscle fibers the pulse techniques showed that, after either a 180 or a 90 degrees pulse, the relaxation of the magnetization is described by a single exponential. This is direct evidence that a fast exchange of protons occurs among the phases of the intracellular water. The data can be fitted with a model in which the bulk of the muscle water is in a phase which has properties similar to those of a dilute salt solution, while less than 4-5% of the total water is bound to the protein surface and has short relaxation times. Measurements of T(1) and T(2) in protein solutions showed that no change in the proton relaxation times occurred when heavy meromyosin was bound to actin, when myofibrils were contracted with adenosine triphosphate (ATP), or when globular actin was polymerized.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Cooke R,Wien Rdoi
10.1016/S0006-3495(71)86274-4subject
Has Abstractpub_date
1971-12-01 00:00:00pages
1002-17issue
12eissn
0006-3495issn
1542-0086pii
S0006-3495(71)86274-4journal_volume
11pub_type
杂志文章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
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.05.060
更新日期:2009-09-02 00:00:00
abstract::Monolayers prepared from myelin conserve all the compositional complexity of the natural membrane when spread at the air-water interface. They show a complex pressure-dependent surface pattern that, on compression, changes from the coexistence of two liquid phases to a viscous fractal phase embedded in a liquid phase....
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.112441
更新日期:2007-12-15 00:00:00
abstract::Calculations based on the known dimensions of bull spermatozoa show that the scattered light intensity is strongly dependent upon the relative orientation of the particle to the incident beam. The magnitude of this effect of apparently much greater than for other systems where motility has been investigated by dynamic...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(80)85046-6
更新日期:1980-07-01 00:00:00
abstract::We present in this report a detailed structural study of calf gamma-crystallins both in the solid state and in solution by the newly developed technique of near-infrared (IR) Fourier transform (FT)-Raman spectroscopy as well as by the conventional Raman method. In comparison with conventional laser Raman spectroscopy,...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(91)82071-9
更新日期:1991-08-01 00:00:00
abstract::Cardiac contraction and relaxation dynamics result from a set of simultaneously interacting Ca(2+) regulatory mechanisms. In this study, cardiocyte Ca(2+) dynamics were modeled using a set of six differential equations that were based on theories, equations, and parameters described in previous studies. Among the uniq...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76276-X
更新日期:2000-07-01 00:00:00
abstract::Molecular dynamics simulations were performed to describe the function of the ion-channel-forming toxin α-hemolysin (αHL) in lipid membranes that were composed of either 1,2-diphytanoyl-sn-glycero-3-phospho-choline or 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-choline. The simulations highlight the importance of lipid ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2018.09.009
更新日期:2018-11-06 00:00:00
abstract::The orientational ordering of beta-carotene and crocetin embedded in lamellar model membranes has been investigated by angle-resolved resonance Raman scattering at a temperature well above the phase transition of the lipid chains. It is shown that the ordering of the carotenoids is dependent on the chemical compositio...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(84)84269-1
更新日期:1984-06-01 00:00:00
abstract::The effect of aggregation of gramicidin A' (GA) on the phase structure of dipalmitoylphosphatidylcholine (DPPC) multilamellar vesicles was studied by cw-ESR using a chain-labeled lipid (16PC) at temperatures between 30 degrees and 45 degreesC that span the main phase transition of DPPC. Boundary lipids were observed o...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(99)77195-X
更新日期:1999-01-01 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::Solid-state NMR study shows that the 22-residue K3 peptide (Ser(20)-Lys(41)) from beta(2)-microglobulin (beta(2)m) adopts a beta-strand-loop-beta-strand conformation in its fibril state. Residue Pro(32) has a trans conformation in the fibril state of the peptide, while it adopts a cis conformation in the native state ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.125054
更新日期:2008-07-01 00:00:00
abstract::We present a three-dimensional tracking routine for nondiffraction-limited particles, which significantly reduces pixel bias. Our technique allows for increased resolution compared to that of previous methods, especially at low magnification or at high signal/noise ratio. This enables tracking with nanometer accuracy ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.03.073
更新日期:2012-05-16 00:00:00
abstract::The diffusion of plastoquinol and its binding to the cytochrome bf complex, which occurs during linear photosynthetic electron transport and is analogous to reaction sequences found in most energy-converting membranes, has been studied in intact thylakoid membranes. The flash-induced electron transfer between the late...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(90)82445-0
更新日期:1990-10-01 00:00:00
abstract::Protein aggregation is linked to more than 30 human pathologies, including Alzheimer's and Parkinson's diseases. Since small oligomers that form at the beginning of the fibrillation process probably are the most toxic elements, therapeutic strategies involving fibril fragmentation could be detrimental. An alternative ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2014.06.029
更新日期:2014-08-05 00:00:00
abstract::Experimental variables of optical tweezers instrumentation that affect RNA folding/unfolding kinetics were investigated. A model RNA hairpin, P5ab, was attached to two micron-sized beads through hybrid RNA/DNA handles; one bead was trapped by dual-beam lasers and the other was held by a micropipette. Several experimen...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.094052
更新日期:2007-05-01 00:00:00
abstract::Fluorescence cross-correlation spectroscopy (FCCS) is used to determine interactions and dissociation constants (K(d)s) of biomolecules. The determination of a K(d) depends on the accurate measurement of the auto- and cross-correlation function (ACF and CCF) amplitudes. In the case of complete binding, the ratio of th...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.01.040
更新日期:2012-03-07 00:00:00
abstract::Melittin has been reported to form toroidal pores under certain conditions, but the atomic-resolution structure of these pores is unknown. A 9-μs all-atom molecular-dynamics simulation starting from a closely packed transmembrane melittin tetramer in DMPC shows formation of a toroidal pore after 1 μs. The pore remains...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2015.04.006
更新日期:2015-05-19 00:00:00
abstract::Keratin intermediate filaments form dynamic intracellular networks, which span the entire cytoplasm and provide mechanical strength to the cell. The mechanical resilience of the keratin intermediate filament network itself is determined by filament bundling. The bundling process can be reproduced in artificial conditi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2020.05.024
更新日期:2020-07-07 00:00:00
abstract::The effect of intracellular (i) and extracellular (o) Na+ on pre-steady-state transient current associated with Na+/Na+ exchange by the Na+/K+ pump was investigated in the vegetal pole of Xenopus oocytes. Current records in response to 40-ms voltage pulses from -180 to +100 mV in the absence of external Na+ were subtr...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.072942
更新日期:2006-03-01 00:00:00
abstract::The following arguments are presented for the observation that curves relating free Ca2+ and force development of thin filament regulated myofilaments of skinned muscle fibers have Hill coefficient (n) greater than 4, which is the number of Ca2+ binding sites on troponin: Activation of the myofilaments is a process re...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(84)84051-5
更新日期:1984-10-01 00:00:00
abstract::It has been a long belief that release of substances from the cell to the extracellular milieu by exocytosis is completed by diffusion of the substances from secretory vesicles through the fusion pore. Involvement of any mechanical force that may be superposed on the diffusion to enhance the releasing process has not ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(02)75159-X
更新日期:2002-07-01 00:00:00
abstract::Ionic channels bathed in mixed solutions of two permeant electrolytes often conduct less current than channels bathed in pure solutions of either. For many years, this anomalous mole fraction effect (AMFE) has been thought to occur only in single-file pores containing two or more ions at a time. Most thinking about ch...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)77942-1
更新日期:1998-05-01 00:00:00
abstract::The suprachiasmatic nucleus governs daily variations of physiology and behavior in mammals. Within single neurons, interlocked transcriptional/translational feedback loops generate circadian rhythms on the molecular level. We present a mathematical model that reflects the essential features of the mammalian circadian ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.040824
更新日期:2004-11-01 00:00:00
abstract::The vibrational energy relaxation of a selected vibrational mode in cytochrome c--a C-D stretch in the terminal methyl group of Met80--has been studied using equilibrium molecular dynamics simulation and normal mode analysis methods. As demonstrated in the pioneering work of Romesberg and co-workers, isotopic labeling...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74575-5
更新日期:2003-09-01 00:00:00
abstract::Interactions between the graft copolymer poly(L-lysine)-g-poly(ethylene glycol), PLL-g-PEG, and two kinds of surface-supported lipidic systems (supported phospholipid bilayers and supported vesicular layers) were investigated by a combination of microscopic and spectroscopic techniques. It was found that the applicati...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.041780
更新日期:2004-09-01 00:00:00
abstract::Recently, our understanding of the structural basis of troponin-tropomyosin's Ca2+-triggered regulation of striated muscle contraction has advanced greatly, particularly via cryo-electron microscopy data. Compelling atomic models of troponin-tropomyosin-actin were published for both apo- and Ca2+-saturated states of t...
journal_title:Biophysical journal
pub_type: 杂志文章,评审
doi:10.1016/j.bpj.2020.11.014
更新日期:2021-01-05 00:00:00
abstract::The absolute direction of the retinal chromophore of bacterio-rhodopsin relative to the membrane plane is investigated by using an optical second-harmonic interference technique. Compared with the known adsorbed geometry of free retinylidene Schiff base on a glass substrate, our data indicate the beta-ionone ring of t...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(89)82883-8
更新日期:1989-05-01 00:00:00
abstract::The orientational order as determined by 2H NMR and the infrared frequencies of the C--H stretching modes of the methylene groups have been measured for several systems (POPC, POPC/cholesterol and POPE), all in the fluid phase, and then were compared; this work reveals an unexpected linear correlation between them. Th...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(93)81351-1
更新日期:1993-01-01 00:00:00
abstract::Can individual cells, including live cells, be imaged using hard x rays? Common wisdom until now required sophisticated staining techniques for this task. We show instead that individual cells and cell details can be detected in culture solution and tissues with no staining and no other contrast-enhancing preparation....
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.103.034991
更新日期:2004-12-01 00:00:00
abstract::We present an analysis of physical chemical constraints on the accuracy of DNA micro-arrays under equilibrium and nonequilibrium conditions. At the beginning of the article we describe an algorithm for choosing a probe set with high specificity for targeted genes under equilibrium conditions. The algorithm as well as ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74837-1
更新日期:2003-01-01 00:00:00
abstract::The wormlike-chain (WLC) model is widely used to describe the energetics of DNA bending. Motivated by recent experiments, alternative, so-called subelastic chain models were proposed that predict a lower elastic energy of highly bent DNA conformations. Until now, no unambiguous verification of these models has been ob...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.05.050
更新日期:2012-07-18 00:00:00