Abstract:
:The bonding rules for actin filament bundles do not lead to a particular packing symmetry, but allow for either regular or disordered filament packing. Indeed, both hexagonal and disordered types of packing are observed in vivo. To investigate factors which control bundle order, as well as size, we examined the effect of protein concentration on the growth of actin-fascin bundles in vitro. We found that bundles require 4-8 d to achieve both maximum size and order. The largest and best ordered bundles were grown at low fascin and high actin concentrations (an initial fascin/actin ratio of 1:200). In contrast, a much larger number of poorly ordered bundles were formed at ratios of 1:25 and 1:50, and most surprisingly, no bundles were formed at 1:300 or 1:400. Based on these observations we propose a two-stage mechanism for bundle growth. The first stage is dominated by nucleation, which requires relatively high concentrations of fascin and which is therefore accompanied by rapid growth. Below some concentration threshold, nucleation ceases and bundles enter the second stage of slow growth, which continues until the supply of fascin is exhausted. By analogy with crystallization, we hypothesize that slower growth produces better order. We are able to use this mechanism to explain our observations as well as previous observations of bundle growth both in vitro and in vivo.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Stokes DL,DeRosier DJdoi
10.1016/S0006-3495(91)82239-1subject
Has Abstractpub_date
1991-02-01 00:00:00pages
456-65issue
2eissn
0006-3495issn
1542-0086pii
S0006-3495(91)82239-1journal_volume
59pub_type
杂志文章abstract::Two-dimensional solid-state 31P NMR has been used to investigate the orientational exchange of phospholipids in gel and liquid-crystalline aqueous multilamellar dispersions and oriented multibilayers, and in biological membranes. In liquid-crystalline L alpha multilamellar dispersions, orientational exchange originate...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(91)82198-1
更新日期:1991-01-01 00:00:00
abstract::Neal and Cunningham (Neal, M. J., and J. R. Cunningham. 1995. J. Physiol. (Lond.). 482:363-372) showed that GABA(B) agonists and glycinergic antagonists enhance the light-evoked release of retinal acetylcholine. They proposed that glycinergic cells inhibit the cholinergic Starburst amacrine cells and are in turn inhib...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.072256
更新日期:2006-07-15 00:00:00
abstract::Historically, predicting macroscopic blood flow characteristics such as viscosity has been an empirical process due to the difficulty in rigorously including the particulate nature of blood in a mathematical representation of blood rheology. Using a two-dimensional lattice Boltzmann approach, we have simulated the flo...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.104.051151
更新日期:2005-03-01 00:00:00
abstract::We have measured, using infrared spectroscopy, the hydrogen/deuterium exchange rates of the amide protons in the photosynthetic antenna of Rhodospirillum rubrum. These measurements were made not only on the intact protein in detergent solution but also on two dissociated forms (B820 and B777). We have, on the basis of...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)74022-6
更新日期:1998-02-01 00:00:00
abstract::Prior work has shown that concentration profiles of platelets in flowing whole blood and of platelet-sized beads in flowing blood suspensions can include near-wall excesses. A model to describe this phenomenon was built about a single-component convective diffusion equation. To incorporate redistribution to preferred ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80595-8
更新日期:1994-09-01 00:00:00
abstract::The effects of intracellular magnesium ions and extracellular calcium and magnesium ions on the delayed rectifier potassium ion channel, IK, were investigated from intracellularly perfused squid giant axons. Cao+2 and Mgo+2 both blocked IK in a voltage-independent manner with a KD of approximately 100 and 500 mM, resp...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(95)80047-0
更新日期:1995-11-01 00:00:00
abstract::Thermodynamic analysis of metabolic networks has recently generated increasing interest for its ability to add constraints on metabolic network operation, and to combine metabolic fluxes and metabolite measurements in a mechanistic manner. Concepts for the calculation of the change in Gibbs energy of biochemical react...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.09.043
更新日期:2010-11-17 00:00:00
abstract::Two piezoelectric constants (polarization per unit stress, d=d'-id'', and polarization per unit strain, e=e'-ie''), the elastic constant, and dielectric constant are determined for oriented collagen at different hydration levels at 10 Hz from -150 to 50 degrees C. With no hydration (approximately 0% H2O), d' increases...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(76)85741-4
更新日期:1976-08-01 00:00:00
abstract::Two-color spatio-temporal image cross-correlation spectroscopy (STICCS) is a new, to our knowledge, image analysis method that calculates space-time autocorrelation and cross-correlation functions from fluorescence intensity fluctuations. STICCS generates cellular flow and diffusion maps that reveal interactions and c...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.08.060
更新日期:2012-10-17 00:00:00
abstract::Flagellin is the subunit of the bacterial filament, the micrometer-long propeller of a bacterial flagellum. The protein is believed to undergo unfolding for transport through the channel of the filament and to refold in a chamber at the end of the channel before being assembled into the growing filament. We report a t...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.123927
更新日期:2008-05-15 00:00:00
abstract::The molecular code of specific DNA recognition by proteins as a paradigm in molecular biology remains an unsolved puzzle primarily because of the subtle interplay between direct protein-DNA interaction and the indirect contribution from water and ions. Transformation of the nonspecific, low affinity complex to a speci...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.063263
更新日期:2005-08-01 00:00:00
abstract::The mechanisms by which extracellular electric field stimuli induce the (re)excitation of cardiac cells in various stages of refractoriness are still not well understood. We modeled the interactions between an isolated cardiac cell and imposed extracellular electric fields to determine the mechanisms by which relative...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(96)79692-3
更新日期:1996-03-01 00:00:00
abstract::An approach is introduced to characterize conformational ensembles of intrinsically unstructured peptides on the atomic level using two-dimensional solid-state NMR data and their combination with molecular dynamics simulations. For neurotensin, a peptide that binds with high affinity to a G-protein coupled receptor, t...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.059964
更新日期:2005-09-01 00:00:00
abstract::The high gradient magnetic separation technique has been applied to separate paramagnetic erythrocytes from a cell suspension that also contained diamagnetic cells. Paramagnetism was induced in the red blood cells by oxidizing the iron atoms in the cell hemoglobin to the ferric state (methemoglobin). Diamagnetic cells...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(78)85482-4
更新日期:1978-05-01 00:00:00
abstract::Molecular chaperones are large proteins or protein complexes from which many proteins require assistance in order to fold. One unique property of molecular chaperones is the cavity they provide in which proteins fold. The interior surface residues which make up the cavities of molecular chaperone complexes from differ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2012.10.040
更新日期:2012-12-19 00:00:00
abstract::Previous studies have demonstrated that the carboxyl terminus of the gap junction protein Cx43 (Cx43CT) can act as an independent, regulatory domain that modulates intercellular communication in response to appropriate chemical stimuli. Here, we have used NMR, chemical cross-linking, and analytical ultracentrifugation...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.103.039230
更新日期:2004-07-01 00:00:00
abstract::Influenza A virus M2 protein is known to form acid-activated, proton-selective, amantadine-sensitive channels. We directly measured proton uptake in vesicles containing reconstituted M2 by monitoring external pH after addition of valinomycin to vesicles with 100-fold-diluted external [K(+)]. External pH typically incr...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.109082
更新日期:2008-01-15 00:00:00
abstract::The use of propagation invariant Bessel beams has enabled high-resolution subcellular light sheet fluorescence microscopy. However, the energy within the concentric side lobe structure of Bessel beams increases significantly with propagation length, generating unwanted out-of-focus fluorescence that enforces practical...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2015.05.013
更新日期:2015-06-16 00:00:00
abstract::Previous data as well as new results are examined with a view to determining the boundary conditions which present experimental information places on a satisfactory polypeptide chain model for the structure of feather keratin. Our studies indicate these conditions to include the following: (1) A 189 A identity period,...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/s0006-3495(61)86903-8
更新日期:1961-07-01 00:00:00
abstract::Sum-frequency vibrational spectroscopy (SFVS) is used to measure the intrinsic rate of lipid flip-flop for 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), and 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) in planar-supported lipid bilayers (PSs). Asymmetric P...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.065672
更新日期:2005-10-01 00:00:00
abstract::The accommodation of chain-length mismatch in liquid crystal phase bilayers was examined by using deuterium nuclear magnetic resonance to obtain smoothed orientational order parameter profiles for acyl chains of both components in binary lipid mixture bilayers. Mixtures of dimyristoylphosphatidylcholine (DMPC) and dis...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(95)80219-5
更新日期:1995-02-01 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::Antibodies are key tools in biomedical research and medicine. Their binding properties are classically measured in solution and characterized by an affinity. However, in physiological conditions, antibodies can bridge an immune effector cell and an antigen-presenting cell, implying that mechanical forces may apply to ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2019.03.012
更新日期:2019-04-23 00:00:00
abstract::When perfused internally through crayfish giant axons, pronase removed sodium inactivation more than three times as fast at -100 mV as compared with -30 mV. N-bromoacetamide, applied internally, removed sodium inactivation twice as fast at -100 mV as at -30 mV, and the relative rate of removal declined with membrane d...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(85)83952-7
更新日期:1985-04-01 00:00:00
abstract::The interpretation of phi-values has led to an understanding of the folding transition state ensemble of a variety of proteins. Although the main guidelines and equations for calculating phi are well established, there remains some controversy about the quality of the numerical values obtained. By analyzing a complete...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.113241
更新日期:2008-06-01 00:00:00
abstract::Coupled folding-binding is central to the function of many intrinsically disordered proteins, yet not fully understood. With a continuous three-letter protein model, we explore the free-energy landscape of pairs of interacting sequences and how it is impacted by 1), variations in the binding mechanism; and 2), the add...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.12.008
更新日期:2012-02-08 00:00:00
abstract::Fluorescent proteins are often used as reporters of transcriptional activity. Here we present a mathematical characterization of a novel fluorescent reporter that was recently engineered to have a short half-life (approximately 12 min). The advantage of this destabilized protein is that it can track the transient tran...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.122200
更新日期:2008-03-15 00:00:00
abstract::The effect of a transmembrane peptide on the domain structure of a two-component, two-phase lipid bilayer composed of dimyristoyl phosphatidylcholine (DMPC) and distearoyl phosphatidylcholine (DSPC) was examined by spin label electron spin resonance (ESR) spectroscopy. The peptide, pOmpA, is the hydrophobic, 25-residu...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80989-0
更新日期:1994-06-01 00:00:00
abstract::The geminate recombination kinetics of CO-myoglobin strongly deviates from single exponential behavior in contrast to what is expected for unimolecular reactions (1). At low temperatures, this result was attributed to slowly exchanging conformational states which differ substantially in barrier height for ligand bindi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(93)81554-6
更新日期:1993-06-01 00:00:00
abstract::We analyzed the microstructure in the first-order laser diffraction line from both resting and tetanically contracting single twitch fibers from frog anterior tibial muscle to see if the distribution of sarcomere lengths is continuous or discrete. Measuring the distance between adjacent microstructural elements lying ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(82)84695-X
更新日期:1982-02-01 00:00:00