Abstract:
:We introduce the use of microfabrication techniques to construct on a silicon wafer a synthetic capillary bed with 2.5- to 4-micron (mu)-wide channels. Establishment of a fluid pressure gradient allowed us to observe simultaneously using optical microscopy hundreds of cells flowing through the bed at physiological speeds. We find a large distribution of mobilities among red cells flowing through the structure; smaller channels provide a greater impedance to flow than larger ones, indicating that kinetic drag variations provide the origin of the distribution. The mobility of a particular cell is not correlated with the cell diameter but appears to be inversely correlated with intracellular calcium concentration of the cell, as determined by fluorescence of the calcium-binding dye fluo-3 AM. Also, we are able to use the parallel processing nature of our arrays to observe isolated events where the rigidity of the red cell seems to change suddenly over several orders of magnitude as it blocks a channel in the array.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Brody JP,Han Y,Austin RH,Bitensky Mdoi
10.1016/S0006-3495(95)80443-1subject
Has Abstractpub_date
1995-06-01 00:00:00pages
2224-32issue
6eissn
0006-3495issn
1542-0086pii
S0006-3495(95)80443-1journal_volume
68pub_type
杂志文章abstract::The temporal dynamics of the concentrations of several proteins are tightly regulated, particularly for critical nodes in biological networks such as transcription factors. An important mechanism to control transcription factor levels is through autoregulatory feedback loops where the protein can bind its own promoter...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.08.005
更新日期:2011-09-21 00:00:00
abstract::The 77-K resonance Raman vibrational spectrum of intact goldfish rod photoreceptors containing 3,4-dehydro (A2) retinal is dominated by scattering from the 9-cis component of the steady state at all excitation wavelengths. Intact goldfish photoreceptors were regenerated with an A1-retinal chromophore to determine whet...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(87)83250-2
更新日期:1987-10-01 00:00:00
abstract::Cubic insulin crystals contain a binding site for monovalent cations in a cavity of the crystal dyad in which the bound cation is ligated by protein atomic dipoles and water molecules. These types of interaction are analogous to interactions that occur in small cation-selective carrier and channel molecules. X-ray dif...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/s0006-3495(94)80795-7
更新日期:1994-02-01 00:00:00
abstract::We investigate the effects of two structurally similar small cyclic molecules: salicylic acid and perillic acid on a zwitterionic model lipid bilayer, and show that both molecules might have biological activity related to membrane thinning. Salicylic acid is a nonsteroidal antiinflammatory drug, some of the pharmacolo...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.11.009
更新日期:2010-12-15 00:00:00
abstract::Multiconformation membrane proteins are mechanosensitive (MS) if their conformations displace different bilayer areas. Might MS closed-closed transitions serve as tension buffers, that is, as membrane "spandex"? While bilayer expansion is effectively instantaneous, transitions of bilayer-embedded MS proteins are stoch...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.08.054
更新日期:2009-11-18 00:00:00
abstract::Stabilized intermediate redox states of cytochrome c are generated by radiolytic reduction of initially oxidized enzyme in glass matrices at liquid nitrogen temperature. In the intermediate states the heme group is reduced by hydrated electrons, whereas the protein conformation is restrained close to its oxidized form...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(83)84340-9
更新日期:1983-08-01 00:00:00
abstract::Recent work has introduced a new fluorescent voltage sensor, ASAP1, which can monitor rapid trains of action potentials in cultured neurons. This indicator is based on the Gallus gallus voltage-sensitive phosphatase with the phosphatase domain removed and a circularly permuted GFP placed in the S3-S4 linker. However, ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2017.10.018
更新日期:2017-11-21 00:00:00
abstract::To investigate the properties of a pure liquid ordered (Lo) phase in a model membrane system, a series of saturated phosphatidylcholines combined with cholesterol were examined by variable temperature multinuclear (1H, 2H, 13C, 31P) solid-state NMR spectroscopy and x-ray scattering. Compositions with cholesterol conce...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.056499
更新日期:2006-04-01 00:00:00
abstract::Direct spectroscopic measurements of rotational motions of proteins and large protein segments are crucial to understanding the molecular dynamics of protein function. Fluorescent probes and spin labels attached to proteins have proved to be powerful tools in the study of large-scale protein motions. Fluorescence depo...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(78)85394-6
更新日期:1978-11-01 00:00:00
abstract::A two-dimensional stochastic model for the dynamics of microtubules in gliding-assay experiments is presented here, which includes the viscous drag acting on the moving fiber and the interaction with the kinesins. For this purpose, we model kinesin as a spring, and explicitly use parameter values to characterize the m...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)76223-6
更新日期:2001-06-01 00:00:00
abstract::Plant light-harvesting complex II (LHCII) is the key antenna complex for plant photosynthesis. We present coarse-grained molecular dynamics simulations of monomeric and trimeric LHCII in a realistic thylakoid membrane environment based on the Martini force field. The coarse-grained protein model has been optimized wit...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2019.03.009
更新日期:2019-04-23 00:00:00
abstract::Many experiments have measured the effect of force on the dissociation of single selectin bonds, but it is not yet clear how the force dependence of molecular dissociation can influence the rolling of cells expressing selectin molecules. Recent experiments using constant-force atomic force microscopy or high-resolutio...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.082321
更新日期:2007-02-01 00:00:00
abstract::Cell migration is based on an actin treadmill, which in turn depends on recycling of G-actin across the cell, from the rear where F-actin disassembles, to the front, where F-actin polymerizes. To analyze the rates of the actin transport, we used the Virtual Cell software to solve the diffusion-drift-reaction equations...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.108.130096
更新日期:2008-08-01 00:00:00
abstract::The hydrodynamic properties of rigid particles are calculated from models composed of spherical elements (beads) using theories developed by Kirkwood, Bloomfield, and their coworkers. Bead models have usually been built in such a way that the beads fill the volume occupied by the particles. Sometimes the beads are few...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(99)77457-6
更新日期:1999-06-01 00:00:00
abstract::We have considered whether lecithin surface films below the gel-liquid crystal transition temperature, Tc, are in unique physical states. In general, below Tc, equilibrium films do not exist when surface pressures, pi, exceed about 0.1 dyn/cm. Since surface pressure-surface area isotherms of lecithin films below Tc al...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(77)85615-4
更新日期:1977-06-01 00:00:00
abstract::The relationship between calcium current and transmitter release was studied in squid giant synapse. It was found that the voltage-dependent calcium current triggers the release of synaptic transmitter in direct proportion to its magnitude and duration. Transmitter release occurs with a delay of approximately 200 mus ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(81)84899-0
更新日期:1981-03-01 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::Nitrile hydratase (NHase) is an enzyme used in the industrial biotechnological production of acrylamide. The active site, which contains nonheme iron or noncorrin cobalt, is buried in the protein core at the interface of two domains, alpha and beta. Hydrogen bonds between betaArg-56 and alphaCys-114 sulfenic acid (alp...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.116665
更新日期:2008-05-15 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::In the photocycle of bacteriorhodopsin at pH 7, a proton is ejected to the extracellular medium during the protonation of Asp-85 upon formation of the M intermediate. The group that releases the ejected proton does not become reprotonated until the prephotolysis state is restored from the N and O intermediates. In con...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.06.022
更新日期:2012-08-08 00:00:00
abstract::Many organs adapt to their mechanical environment as a result of physiological change or disease. Cells are both the detectors and effectors of this process. Though many studies have been performed in vitro to investigate the mechanisms of detection and adaptation to mechanical strains, the cellular strains remain unk...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(02)75214-4
更新日期:2002-08-01 00:00:00
abstract::Cis-parinaric acid (PA) binds to a hydrophobic pocket formed between the heavy chain of myosin subfragment-1 (S1) and the 41-residue N-terminal of essential light chain 1 (A1). The binding is strong (Ka = 5.6 x 10(7) M-1) and rigid (polarization = 0.334). PA does not bind to myofibrils in which A1 has been extracted o...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(97)78871-4
更新日期:1997-05-01 00:00:00
abstract::Guanidinium and acetamidinium, when added to the bathing solution in concentrations of approximately 0.1M, cause brief blocks in the single channel potassium currents from channels formed in planar lipid bilayers by gramicidin A. Single channel lifetimes are not affected indicating that the channel structure is not mo...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(91)82303-7
更新日期:1991-04-01 00:00:00
abstract::We are interested in modeling the membrane-spanning domain of the serotonin 5-HT1A G-protein coupled receptor. This superfamily of proteins is predicted to share the topology of the seven transmembrane helices of bacteriorhodopsin (BR), even though no significant sequence homology had been identified. We found signifi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(92)81794-0
更新日期:1992-04-01 00:00:00
abstract::Xenopus oocytes express mechanosensitive (MS(XO)) channels that can be studied in excised patches of membrane with the patch-clamp technique. This study examines the steady-state kinetic gating properties of MS(XO) channels using detailed single-channel analysis. The open and closed one-dimensional dwell-time distribu...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)75857-2
更新日期:2001-10-01 00:00:00
abstract::The partial specific volume and adiabatic compressibility of proteins reflect the hydration properties of the solvent-exposed protein surface, as well as changes in conformational states. Reverse micelles, or water-in-oil microemulsions, are protein-sized, optically-clear microassemblies in which hydration can be expe...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)76243-1
更新日期:2001-06-01 00:00:00
abstract::Fluo-3 is an unusual tetracarboxylate Ca2+ indicator. For recent lots supplied by Molecular Probes Inc. (Eugene, OR), FMAX, the fluorescence intensity of the indicator in its Ca(2+)-bound form, is approximately 200 times that of FMIN, the fluorescence intensity of the indicator in its Ca(2+)-free form. (For earlier lo...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(93)81112-3
更新日期:1993-08-01 00:00:00
abstract::A method for fabricating biomimetic surfaces from intact cell membranes is described. A monolayer of alkanethiol on gold is covered by a second layer derived from the components of erythrocyte membranes either by self-assembly or by Langmuir-Blodgett methods. The resulting asymmetric hybrid layer was characterized by ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(97)78334-6
更新日期:1997-12-01 00:00:00
abstract::Mislocalization and aggregation of the huntingtin protein are related to Huntington's disease. Its first exon-more specifically the first 17 amino acids (Htt17)-is crucial for the physiological and pathological functions of huntingtin. It regulates huntingtin's activity through posttranslational modifications and serv...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2015.02.001
更新日期:2015-03-10 00:00:00
abstract::This work presents a methodology to measure and quantitatively interpret force curves on supported lipid bilayers in water. We then use this method to correlate topographic imaging contrast in atomic force microscopy (AFM) images of phase-separated Langmuir-Blodgett bilayers with imaging load. Force curves collected o...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76364-8
更新日期:2000-08-01 00:00:00