Abstract:
:Rhodobacter sphaeroides can swim toward a wide range of attractants (a process known as taxis), propelled by a single rotating flagellum. The reversals of motor direction that cause tumbles in Eschericia coli taxis are replaced by brief motor stops, and taxis is controlled by a complex sensory system with multiple homologues of the E. coli sensory proteins. We tethered photosynthetically grown cells of R. sphaeroides by their flagella and measured the response of the flagellar motor to changes in light intensity. The unstimulated bias (probability of not being stopped) was significantly larger than the bias of tethered E. coli but similar to the probability of not tumbling in swimming E. coli. Otherwise, the step and impulse responses were the same as those of tethered E. coli to chemical attractants. This indicates that the single motor and multiple sensory signaling pathways in R. sphaeroides generate the same swimming response as several motors and a single pathway in E. coli, and that the response of the single motor is directly observable in the swimming pattern. Photo-responses were larger in the presence of cyanide or the uncoupler carbonyl cyanide 4-trifluoromethoxyphenylhydrazone (FCCP), consistent with the photo-response being detected via changes in the rate of electron transport.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Berry RM,Armitage JPdoi
10.1016/S0006-3495(00)76678-1subject
Has Abstractpub_date
2000-03-01 00:00:00pages
1207-15issue
3eissn
0006-3495issn
1542-0086pii
S0006-3495(00)76678-1journal_volume
78pub_type
杂志文章abstract::The scattering and absorption coefficients of many homogeneous biological tissues such as muscle, skin, white matter in the brain, and dentin are often anisotropically oriented with respect to their bounding interface. In consequence the curves of equal intensity of re-emitted light on the surface of the slab will no ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.058305
更新日期:2005-05-01 00:00:00
abstract::The thermophilic Bacillus caldolyticus cold shock protein (Bc-Csp) differs from the mesophilic Bacillus subtilis cold shock protein B (Bs-CspB) in 11 of the 66 residues. Stability measurements of Schmid and co-workers have implicated contributions of electrostatic interactions to the thermostability. To further elucid...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)75027-9
更新日期:2003-04-01 00:00:00
abstract::Are protein nonpolar cavities filled with water molecules? Although many experimental and theoretical investigations have been done, particularly for the nonpolar cavity of IL-1 beta, the results are still conflicting. To study this problem from the thermodynamic point of view, we calculated hydration free energies of...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.01.029
更新日期:2010-06-16 00:00:00
abstract::Homooligomerization of proline utilization A (PutA) bifunctional flavoenzymes is intimately tied to catalytic function and substrate channeling. PutA from Bradyrhizobium japonicum (BjPutA) is unique among PutAs in that it forms a tetramer in solution. Curiously, a dimeric BjPutA hot spot mutant was previously shown to...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2018.04.046
更新日期:2018-06-19 00:00:00
abstract::Molecular dynamics simulations in simplified models allow one to study the scaling properties of folding times for many proteins together under a controlled setting. We consider three variants of the Go models with different contact potentials and demonstrate scaling described by power laws and no correlation with the...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74867-X
更新日期:2003-01-01 00:00:00
abstract::It is often assumed that pH(i) is spatially uniform within cells. A double-barreled microperfusion system was used to apply solutions of weak acid (acetic acid, CO(2)) or base (ammonia) to localized regions of an isolated ventricular myocyte (guinea pig). A stable, longitudinal pH(i) gradient (up to 1 pH(i) unit) was ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.051391
更新日期:2005-04-01 00:00:00
abstract::Inactivation is a fundamental property of voltage-gated ion channels. Fast inactivation of Na(+) channels involves channel block by the III-IV cytoplasmic interdomain linker. The mechanisms of nonfast types of inactivation (intermediate, slow, and ultraslow) are unclear, although the ionic environment and P-loops rear...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.100248
更新日期:2007-09-01 00:00:00
abstract::The freshwater polyp Hydra can regenerate from tissue fragments or random cell aggregates. We show that the axis-defining step ("symmetry breaking") of regeneration requires mechanical inflation-collapse oscillations of the initial cell ball. We present experimental evidence that axis definition is retarded if these o...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2008.09.062
更新日期:2009-02-18 00:00:00
abstract::The bacterial flagellar motor couples the flow of protons across the cytoplasmic membrane to the rotation of a helical flagellar filament. Using tethered cells, we have measured the stall torque required to block this rotation and compared it with the torque of the running motor over a wide range of values of proton-m...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(87)83230-7
更新日期:1987-09-01 00:00:00
abstract::Gigaohm recordings have been made from glutamate receptor channels in excised, outside-out patches of collagenase-treated locust muscle membrane. The channels in the excised patches exhibit the kinetic state switching first seen in megaohm recordings from intact muscle fibers. Analysis of channel dwell time distributi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(90)82367-5
更新日期:1990-07-01 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
pub_type: 杂志文章
doi:10.1016/S0006-3495(90)82570-4
更新日期:1990-03-01 00:00:00
abstract::In this paper, we report on the presence of cation binding areas on bovine serum amine oxidase, where metal ions of the groups IA and IIA, such as Na(+), K(+), Cs(+), Mg(2+), and Ca(2+), bind with various affinities. We found a cation-binding area that influences the enzyme activity if occupied, so that the catalytic ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(02)73983-0
更新日期:2002-10-01 00:00:00
abstract::The photoelectron quantum yields of 21 common amino acids and 15 polyamino acids were measured in the 180-240 nm wavelength region. On the average, the quantum yields of these two groups exhibit quite similar wavelength dependence. For lambda > 220 nm all amino acid and polyamino acid quantum yields are =10(-7) elec...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(74)85927-8
更新日期:1974-06-01 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
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76539-8
更新日期:2000-12-01 00:00:00
abstract::This paper is concerned with the nature of the transmembrane potential induced in an inactive nerve fiber lying in an impressed potential field within a nerve trunk. The impressed potential field is assumed to be produced by the synchronous activity of other fibers within the trunk; an expression for the induced trans...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(71)86214-8
更新日期:1971-03-01 00:00:00
abstract::We study a differential equation that models nerve impulse transmission. The nonlinearity is simplified to be piecewise linear in order to allow explicit solution. In general, two solitary impulse solutions are exhibited. The temporal stability of these solutions is analyzed by a technique that identifies the number o...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(78)85511-8
更新日期:1978-02-01 00:00:00
abstract::In this study maximum shortening velocity (Vmax) and isometric tension (P0) in skinned single fibers from rat slow soleus (SOL) and fast superficial vastus lateralis (SVL) muscles were examined after varying degrees of filament lattice compression with dextran. In both fiber types Vmax was greatest in the absence of d...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(87)83197-1
更新日期:1987-07-01 00:00:00
abstract::Single actin filaments were analyzed in solutions ranging from dilute (0.2 microgram/ml), where filaments interact only with solvent, to concentrations (4.0 mg/ml) at which F-actin forms a nematic phase. A persistence length of approximately 1.8 microns and an average length of approximately 22 microns (Kaufmann et al...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79630-3
更新日期:1996-02-01 00:00:00
abstract::It is shown that alpha-helical content of eleven proteins is well correlated with alanine plus leucine content. These residues, taken singly or together, are to a first approximation randomly distributed in the four proteins whose tertiary structures have been determined (i.e., myoglobin, lysozyme, ribonuclease, alpha...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(68)86553-1
更新日期:1968-11-01 00:00:00
abstract::A major component of green tea extracts, catechin (-)-Epigallocatechin gallate (EGCg), has been reported to be biologically active and interacting with membranes. A recent study reported drastic effects of EGCg on giant unilamellar vesicles (GUVs). In particular, EGCg above 30 microM caused GUVs to burst. Here we inve...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2008.11.007
更新日期:2009-02-01 00:00:00
abstract::Verapamil and amlodipine are calcium ion influx inhibitors of wide clinical use. They are partially charged at neutral pH and exhibit amphiphilic properties. The noncharged species can easily cross the lipid membrane. We have measured with solid-state NMR the structural changes induced by verapamil upon incorporation ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.106.089581
更新日期:2006-10-15 00:00:00
abstract::In response to external stimuli, cells modulate their adhesive state by regulating the number and intrinsic affinity of receptor/ligand bonds. A number of studies have shown that cell adhesion is dramatically reduced at room or lower temperatures as compared with physiological temperature. However, the underlying mech...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.06.037
更新日期:2010-09-08 00:00:00
abstract::We report applications of two-photon excitation fluorescence (2PEF) microscopy with subdiffraction-limit resolution for green-fluorescent-protein-tagged cell imaging. The microscope integrates 2PEF microscopy and stimulated emission depletion microscopy in one microscope that has the benefits of both techniques: intri...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.09.038
更新日期:2009-12-16 00:00:00
abstract::Dynamic properties of class A beta-lactamase TEM-1 are investigated from molecular dynamics (MD) simulations. Comparison of MD-derived order parameters with those obtained from model-free analysis of nuclear magnetic resonance (NMR) relaxation data shows high agreement for N-H moieties within alpha- and beta-secondary...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.08.061
更新日期:2010-02-17 00:00:00
abstract::The functional organization of prokaryotic cell membranes, which is essential for many cellular processes, has been challenging to analyze due to the small size and nonflat geometry of bacterial cells. Here, we use single-molecule fluorescence microscopy and three-dimensional quantitative analyses in live Escherichia ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.01.010
更新日期:2016-03-08 00:00:00
abstract::Recent experimental studies (Pusch and Neher, 1988) and theoretical studies (Oliva et al., 1988) have found that the pipette tip is a significant barrier to diffusion in the whole cell patch clamp configuration. In this paper, we extend the theoretical analysis of fluxes between the pipette and cell to include transme...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(90)82418-8
更新日期:1990-09-01 00:00:00
abstract::We have developed a model for the analysis of the forward creatine kinase reaction in muscle as measured by the nuclear magnetic resonance (NMR) technique of magnetization transfer. The model, accounting for the double-exponential behavior observed in some NMR magnetization transfer data, allows for the existence of t...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(87)83416-1
更新日期:1987-06-01 00:00:00
abstract::Exceptions to the Meyer-Overton rule are commonly cited as evidence against indirect, membrane-mediated mechanisms of general anesthesia. However, another interpretation is possible within the context of an indirect mechanism in which solubilization of an anesthetic in the membrane causes a redistribution of lateral p...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)76200-5
更新日期:2001-05-01 00:00:00
abstract::High-efficiency electrofusion between cells of different sizes was achieved by application of fusing electric pulses to cells in centrifuged pellets. Larger target cells (Chinese hamster ovary or L1210 cells) were stacked among smaller human erythrocytes or erythrocyte ghosts by sequential centrifugation at 700 g to f...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79249-4
更新日期:1996-07-01 00:00:00
abstract::Specific amino acid sequence segments have been assigned to locations in the structural map of bacteriorhodopsin using two-dimensional neutron diffraction data and a model building analysis. Models are constructed computationally by building specific regions of the amino acid sequence as alpha helices and then positio...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(83)84391-4
更新日期:1983-06-01 00:00:00