Showing papers in "Biophysical Journal in 2001"

TL;DR: A new tool is presented and applied to the retinol-binding protein, which indicates enhanced flexibility in the region of entry to the ligand binding site and for the portion of the protein binding to its carrier protein.

TL;DR: The new method substantially improves the resolution and reliability of models derived from scattering data and makes solution scattering a useful technique in large-scale structural characterization of proteins.

TL;DR: The notion that in biomembranes selected lipids could laterally aggregate to form more ordered, detergent-resistant lipid rafts into which glycosphingolipid- and cholesterol-rich lipid domains partition is strongly supported by this study.

TL;DR: This study predicted the fluorescence wavelengths of 19 tryptophans in 16 proteins using a hybrid quantum mechanical-classical molecular dynamics method with the assumption that only electrostatic interactions of thetryptophan ring electron density with the surrounding protein and solvent affect the transition energy.

TL;DR: It is concluded that, among naturally produced peptides that are investigated, only alamethicin conforms to the barrel-stave model, and other peptides, including magainins, melittin and protegrins, all appear to induce transmembrane pores that conform to the toroidal model.

TL;DR: Stochastic bistability where the deterministic equations predict monostability and vice-versa is found; among them, bifurcations driven solely by changing the rate of operator fluctuations even as the underlying deterministic system remains unchanged are found.

TL;DR: The magnitude of the deforming forces in the optical stretcher bridges the gap between optical tweezers and atomic force microscopy for the study of biologic materials.

TL;DR: Some simulations have been carried out to determine the rupture properties of mixed bilayers of phosphatidylethanolamine and C(12)E(6), and indicate that the area of a pure lipid bilayer can be increased by a factor 2, and why dividing cells are more at risk than static cells.

TL;DR: It is found that cross-correlation is the most accurate algorithm for large particles, however, for point sources, direct Gaussian fit to the intensity distribution is the superior algorithm in terms of both accuracy and precision, and is themost robust at low signal-to-noise.

TL;DR: A modified method for FRET quantification in cultured cells using conventional fluorescence microscopy was presented, which gave consistent FRET values that could be compared among different cells with varying protein expression levels.

TL;DR: Observations suggest a frontal towing mechanism for cell migration, where dynamic traction forces at the leading edge actively pull the cell body forward.

TL;DR: Electron microscopy of cervical mucus confirmed that the mesh spacing between mucin fibers is large enough for small viruses to diffuse essentially unhindered through mucus, and diffusion by IgM-Fc(5 mu), the Fc pentamer core of an IgM with all 10 Fab moieties removed, was comparably slowed by mucus.

TL;DR: This study studied this kind of damage in bovine adrenal chromaffin cells, using two different indicators of damage: changes in resting [Ca(2+)] level and the degranulation reaction, and found that damage is proportional to the integral (over space and time) of light intensity raised to a power approximately 2.5.

TL;DR: The fluid nature of rafts, demonstrated in this study, may be important for permitting dynamic interactions between proteins localized within rafts.

TL;DR: This study should be considered as a step toward a more complete understanding of lateral heterogeneity within biomembranes, as cholesterol may play a role in domain separation on the nanometer scale.

TL;DR: This work succeeded in restricting kinesin-driven movements of microtubules along linear tracks by using micrometer-scaled grooves lithographically fabricated on glass surfaces, and accomplished the extraction of unidirectional movement from the bidirectional movements along thelinear tracks by adding arrowhead patterns on the tracks.

TL;DR: The simulated results suggest that the most primitive stem cells, which are located even further away from BM sinuses, are likely located in a very low pO(2) environment.

TL;DR: The ability of nicked DNA to withstand forces greater than that at the transition midpoint is explained as a result of the one-dimensional nature of the melting transition, which leads to alternating zones of melted and unmelted DNA even substantially above the melting midpoint.

TL;DR: Simulation results support the hypothesis that the smaller density and the slower reactivation kinetics of the Ca(2+)-independent transient outward K(+) current (I(t)) in the endocardial myocytes can account for the longer action potential duration (APD), and more prominent rate dependence in that cell type.

TL;DR: An oligomerization-induced trapping model is proposed in which, when oligomers are formed, they are trapped in place due to greatly enhanced tethering and corralling effects of the membrane skeleton on oligomers (compared with monomers).

TL;DR: Analysis of the structural changes imposed by lysolipids show that, opposite to DOPE itself, PC lysOLipids add high positive curvature, with R(0) = +38 to +60 A, depending on chain length, while LysoPEs, in contrast, add very small curvatures.

TL;DR: A mathematical model of the extrinsic or tissue factor (TF) pathway of blood coagulation is formulated and results from a computational study of its behavior are presented, suggesting that platelets adhering to and covering the subendothelium, rather than chemical inhibitors, may play the dominant role in blocking the activity of the TF:VIIa enzyme complex.

TL;DR: This work has applied the stretched-exponential function (StrEF) to time-domain whole-field fluorescence lifetime imaging (FLIM), yielding both excellent tissue contrast and goodness of fit using data from rat tissue, and notes that for many biological samples for which there is no a priori knowledge of multiple discrete exponential fluorescence decay profiles, the StrEF is likely to provide a truer representation of the underlying fluorescence dynamics.

TL;DR: An algorithm is presented that allows prediction of the performance of FCS measurements in various cases, which is important for finding optimal experimental conditions and improves parameter estimation, compared to currently used theoretical approximations for the SD.

TL;DR: It is suggested that the spreading of this contact area leads to expulsion of PEG-ceramide and triggers processes that result in the formation of multilamellar systems with internalized polynucleotides, which are of utility for liposomal delivery of macromolecular drugs.

TL;DR: The utility of the model for identifying toxic Abeta oligomeric specie(s) is demonstrated and should prove useful for designing compounds that inhibit Abeta aggregation and/or toxicity.

TL;DR: Using a novel x-ray absolute-scale refinement method, this work determines the location, orientation, and likely conformation of monomeric melittin in oriented phosphocholine lipid multilayers and provides direct structural evidence that self-association of amphipathic helices may be the crucial initial step toward membrane lysis.

TL;DR: It is found that larger proteins are packed more loosely than smaller proteins, and the enthalpies of folding are independent of the packing density of a protein, indicating that van der Waals interactions are not a dominant component of the folding forces.

TL;DR: A tissue cylinder solely occupied by granulocytic progenitors is constructed to provide a physiologically relevant limiting case and modeling results suggest that stem and progenitor cells experience a low pO(2) environment in the BMHC.

TL;DR: Results suggest that bicelles with low q retain the morphology and bilayer organization typical of their liquid-crystalline counterparts, making them useful membrane mimetics.