Abstract:
:The viral genome and replicative enzymes of the human immunodeficiency virus are encased in a shell consisting of assembled mature capsid protein (CA). The core shell is a stable, effective protective barrier, but is also poised for dissolution on cue to allow transmission of the viral genome into its new host. In this study, static light scattering (SLS) and dynamic light scattering (DLS) were used to examine the entire range of the CA protein response to an environmental cue (pH). The CA protein assembled tubular structures as previously reported but also was capable of assembling spheres, depending on the pH of the protein solution. The switch from formation of one to the other occurred within a very narrow physiological pH range (i.e., pH 7.0 to pH 6.8). Below this range, only dimers were detected. Above this range, the previously described tubular structures were detected. The ability of the CA protein to form a spherical structure that is detectable by DLS but not by electron microscopy indicates that some assemblages are inherently sensitive to perturbation. The dimers in equilibrium with these assemblages exhibited distinct conformations: Dimers in equilibrium with the spherical form exhibited a compact conformation. Dimers in equilibrium with the rod-like form had an extended conformation. Thus, the CA protein possesses the inherent ability to form metastable structures, the morphology of which is regulated by an environmentally-sensitive molecular switch. Such metastable structures may exist as transient intermediates during the assembly and/or disassembly of the virus core.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Ehrlich LS,Liu T,Scarlata S,Chu B,Carter CAdoi
10.1016/S0006-3495(01)75725-6subject
Has Abstractpub_date
2001-07-01 00:00:00pages
586-94issue
1eissn
0006-3495issn
1542-0086pii
S0006-3495(01)75725-6journal_volume
81pub_type
杂志文章abstract::We performed hole-burning Stark effect experiments on cytochrome c in which the iron of the herne was either removed or replaced by Zn. According to the experiments, the free-base compound has an effective inversion center, even in the protein. The Zn compound, on the other hand, shows quite peculiar features: in the ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79237-8
更新日期:1996-07-01 00:00:00
abstract::Frog skeletal muscle fibers, mechanically skinned under water-saturated silicone oil, swell upon transfer to aqueous relaxing medium (60 mM KCl; 3 mM MgCl(2); 3 mM ATP; 4 mM EGTA; 20 mM Tris maleate; pH = 7.0; ionic strength 0.15 M). Their cross-sectional areas, estimated with an elliptical approximation, increase 2.3...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(77)85573-2
更新日期:1977-08-01 00:00:00
abstract::Bin/Amphiphysin/Rvs-homology (BAR) domains generate and sense membrane curvature by binding the negatively charged membrane to their positively charged concave surfaces. N-BAR domains contain an N-terminal extension (helix-0) predicted to form an amphipathic helix upon membrane binding. We determined the NMR structure...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.108.134155
更新日期:2008-11-01 00:00:00
abstract::Concentrated solutions of bovine beta-lactoglobulin were studied using osmotic stress and rheological techniques. At pH 6.0 and 8.0, the osmotic pressure was largely independent of NaCl concentration and could be described by a hard sphere equation of state. At pH 5.1, close to the isoelectric point, the osmotic press...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.064246
更新日期:2005-08-01 00:00:00
abstract::We investigated the origins of greater clot rigidity associated with FXIIIa-dependent cross-linking. Fibrin clots were examined in which cross-linking was controlled through the use of two inhibitors: a highly specific active-center-directed synthetic inhibitor of FXIIIa, 1,3-dimethyl-4,5-diphenyl-2[2(oxopropyl)thio]i...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(99)77114-6
更新日期:1999-11-01 00:00:00
abstract::Phototropins, major blue-light receptors in plants, are sensitive to blue light through a pair of flavin mononucleotide (FMN)-binding light oxygen and voltage (LOV) domains, LOV1 and LOV2. LOV2 undergoes a photocycle involving light-driven covalent adduct formation between a conserved cysteine and the FMN C(4a) atom. ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2009.01.066
更新日期:2009-07-08 00:00:00
abstract::It has been previously demonstrated that the Stepanov equation provides a rather good description of the absorption/fluorescence spectra in Photosystem I, even though excited state equilibration is not rapid with respect to the excited state decay. In the present article this apparent contradiction is examined analyti...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74805-X
更新日期:2003-12-01 00:00:00
abstract::A phenomenological theory for contracting muscle based on irreversible thermodynamics and the sliding filament theory is developed. The individual cross bridges, considered as subunits, are viewed as linear energy converters with constant transport coefficients. With this view of the subunits, phenomenological equatio...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(70)86290-7
更新日期:1970-02-01 00:00:00
abstract::Photoinduced electron transfer in photosystem I (PS I) proceeds from the excited primary electron donor P700 (a chlorophyll a dimer) via the primary acceptor A0 (chlorophyll a) and the secondary acceptor A1 (phylloquinone) to three [4Fe-4S] clusters, Fx, FA, and FB. Prereduction of the iron-sulfur clusters blocks elec...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)78023-3
更新日期:1998-06-01 00:00:00
abstract::Using the simple argument based on irreversible thermodynamics and the Gouy-Chapman theory of the double layer, we show that the equilibrium distribution of charged lipid molecules between the two surfaces of a bilayer is asymmetric if the two solutions bathing the surfaces have the same ionic strength but contain ion...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(77)85629-4
更新日期:1977-02-01 00:00:00
abstract::One of the unusual properties of elastin is its ability to coacervate, which has been proposed to play an important role in the alignment of monomeric elastin for cross-linking into the polymeric elastin matrix. The temperature at which this transition takes place depends on several factors including protein concentra...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.110809
更新日期:2007-11-15 00:00:00
abstract::Actin dynamics is important in determining cell shape, tension, and migration. Methods such as fluorescent speckle microscopy and spatial temporal image correlation spectroscopy have been used to capture high-resolution actin turnover dynamics within cells in two dimensions. However, these methods are not directly app...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2013.07.057
更新日期:2013-10-15 00:00:00
abstract::Embryo and oocyte cryopreservation is a widely used technology for cryopreservation of genetic resources. One limitation of cryopreservation is the low tolerance to freezing observed for oocytes and embryos rich in lipid droplets. We apply Raman spectroscopy to investigate freezing of lipid droplets inside cumulus-ooc...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2018.06.019
更新日期:2018-08-07 00:00:00
abstract::This study presents what is, to our knowledge, a novel technique by means of which the ratio of the single gating charges of voltage-gated rat brain IIA (rBIIA) sodium and Shaker potassium ion channels was estimated. In the experiment, multiple tandems of enhanced green fluorescent protein were constructed and inserte...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.108.130765
更新日期:2008-08-01 00:00:00
abstract::As normally studied, in the solid state or in solution, poly(beta-benzyl-L-aspartate) (PBLA) differs from the other helical polyamino acids in that its alpha-helical conformation is most stable in the left-handed rather than in the right-handed form. The slightly lower energy per residue for the left-handed form in PB...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)77689-1
更新日期:1998-11-01 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::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
pub_type: 杂志文章
doi:10.1016/S0006-3495(04)74269-1
更新日期:2004-04-01 00:00:00
abstract::Enterococcus hirae V1-ATPase is a molecular motor composed of the A3B3 hexamer ring and the central stalk. In association with ATP hydrolysis, three catalytic AB pairs in the A3B3 ring undergo conformational changes, which lead to a 120° rotation of the central stalk. To understand how the conformational changes of th...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2017.01.029
更新日期:2017-03-14 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
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80537-5
更新日期:1994-08-01 00:00:00
abstract::The energetics of phospholipid aggregation depend on the apparent water-accessible apolar surface area (ASAap), ordering effects of the chains, and headgroup interactions. We quantify the enthalpy and entropy of these interactions separately. For that purpose, the thermodynamics of micelle formation of lysophosphatidy...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)76012-2
更新日期:2001-01-01 00:00:00
abstract::Oriented solid-state NMR in combination with multiple-residue-specific (15)N labeling and extensive numerical spectral analysis is proposed to determine helix conformations of large membrane proteins in native membranes. The method is demonstrated on uniaxially oriented samples of (15)N-methionine, -valine, and -glyci...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.116004
更新日期:2008-01-01 00:00:00
abstract::We have measured the fluorescence spectra of a single fluorophore attached to a single protein molecule in aqueous solution using a total internal reflection fluorescence microscope. The most reactive cysteine residue of myosin subfragment-1 (S1) was labeled with tetramethylrhodamine. The spectral shift induced by a c...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76708-7
更新日期:2000-03-01 00:00:00
abstract::2H-nuclear magnetic resonance (NMR) has been used to study the dynamics of amino acid residues in bacteriorhodopsin with results that depend on the method of sample preparation. We show here that in [2H]-leucine-labeled samples the intensity of the isotropic signal varies according to the degree of residual contaminat...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(87)83278-2
更新日期:1987-11-01 00:00:00
abstract::In this paper we explore the properties of a mathematical model for the passive sodium permeability system of excitable membranes. This model is distinguished by the explicit inclusion of a rate constant which depends not on instantaneous voltage, but on rate of voltage change. Actually, the model is a rather modest m...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(75)85840-1
更新日期:1975-06-01 00:00:00
abstract::A number of models proposed to account for the sodium conductance changes are shown to fall into two classes. The Hodgkin-Huxley (HH) model falls into a class (I) in which the conductance depends on two or more independent variables controlled by independent processes. The Mullins, Hoyt, and Goldman models fall into c...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(68)86540-3
更新日期:1968-10-01 00:00:00
abstract::In a pure fluid-phase lipid, the dependence of the lateral diffusion coefficient on the size of the diffusing particle may be obtained from the Saffman-Delbrück equation or the free-volume model. When diffusion is obstructed by immobile proteins or domains of gel-phase lipids, the obstacles yield an additional contrib...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(93)81471-1
更新日期:1993-04-01 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::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
pub_type: 杂志文章
doi:10.1016/S0006-3495(85)83815-7
更新日期:1985-10-01 00:00:00
abstract::Osmotic stress in the 0.5-5 x 10(6) dyne/cm2 range was used to perturb the hydration of actin-myosin-ATP intermediates during steady-state hydrolysis. Polyethylene glycol (PEG) (1000 to 4000 Da), in the 1 to 10 wt% range, which does not cause protein precipitation, did not significantly affect the apparent KM or the V...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79852-1
更新日期:1996-06-01 00:00:00
abstract::A theory based on the Smolukowski analysis of colloid stability shows that the presence of charged, surface-active serum proteins at the alveolar air-liquid interface can severely reduce or eliminate the adsorption of lung surfactant from the subphase to the interface, consistent with the observations reported in the ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.062646
更新日期:2005-09-01 00:00:00