Showing papers in "Biophysical Journal in 1998"

TL;DR: This work measures the kinetics of adsorption of small (12.5-nm radius) unilamellar vesicles onto SiO2, oxidized gold, and a self-assembled monolayer of methyl-terminated thiols, using a quartz crystal microbalance (QCM).

TL;DR: A helix propensity scale for solvent-exposed residues in the middle positions of alpha-helices is derived, based on measurements ofHelix propensity in 11 systems, including both proteins and peptides.

TL;DR: Measurements of the interaction of the proteins Bcl-2 and Beclin, are shown to document the accuracy of this approach for correction of donor and acceptor concentrations, and cross talk between the different filter units.

TL;DR: The data support the postulate that HERG encodes a major constituent of I(Kr) and suggest that at physiological temperatures HERG contributes current throughout most of the action potential and into the postrepolarization period.

TL;DR: A magnetic bead microrheometer has been designed which allows the generation of forces up to 10(4) pN on 4.5 micron paramagnetic beads to measure local viscoelastic properties of the surface of adhering fibroblasts and a surface shear modulus of mu * is found.

TL;DR: The results establish the application of GFP as a targetable, noninvasive indicator of intracellular pH and suggest that GFP pH sensitivity involves simple protonation events at a pH of >5, but both protonations and conformational changes at lower pH.

TL;DR: In this paper, the authors performed steered molecular dynamics simulations to stretch single titin Ig domains in solution with pulling speeds of 0.5 and 1.0 A/ps, and the force-extension profiles exhibit a single dominant peak for each Ig domain unfolding.

TL;DR: This work has developed an experimental approach, using atomic force microscopy, called force integration to equal limits (FIEL) mapping, to produce robust, internally quantitative maps of relative elasticity, which shows that elasticity is uncoupled from topography and reveal a number of unexpected features.

TL;DR: The molecule's degree of supercoiling could therefore be quantitatively controlled and monitored, and tethered-particle motion analysis allowed us to measure the stretching force acting on the DNA.

TL;DR: In this article, a comparison of confocal and multiphoton fluorescence imaging of identical optical sections within a sample is presented. But the results show that the difference in image contrast is primarily due to scattered emission photons, which reduce the signal and increase the local background.

TL;DR: It is demonstrated that the cell aggregates studied here, when subjected to mechanical deformations, relax as elastic materials on short time scales and as viscous liquids on long time scales.

TL;DR: A computer model is presented that can generate realistic BIACORE data and demonstrates that good estimates of the intrinsic reaction rate constants are recovered even when mass transport influences the binding reaction.

TL;DR: Experimental and theoretical results are in good agreement and a comparison of the precipitation conditions of different kinds of polyelectrolytes suggests a general process.

TL;DR: A novel method for measuring forward and reverse kinetic rate constants, kf0 and kr0, for the binding of individual receptors and ligands anchored to apposing surfaces in cell adhesion, which was applied to examine the interaction between Fc gamma receptor IIIA and immunoglobulin G.

TL;DR: The mechanism of activation of the cardiac calcium release channel/ryanodine receptor (RyR) by luminal Ca2+ was investigated in native canine cardiac RyRs incorporated into lipid bilayers to suggest that the effects of luminalCa2+ are mediated by distinct Ca2-sensitive site(s) at the luminal face of the channel or associated protein.

TL;DR: Ensemble-averaging of nonaxisymmetrical, deformed structures exhibiting anisotropic strain are shown to provide an answer to the basic question of how a triangulated mesh such as that of the red cell cytoskeleton deforms in experiment.

TL;DR: In a much narrower range of binding, where ANS- is sometimes assumed to act as a hydrophobic probe, ANs- may become fluorescent, the broad overall range is sharply dependent on electrostatic, ion pair formation, where the organic sulfonate group is the major determinant of binding.

TL;DR: The pore dimensions, conductance, and the properties of water inside the pore, based on a molecular dynamics simulation of the OmpF trimer, 318 palmitoyl-oleoysl-phosphatidylethanolamine lipids, 27 Na+ ions, and 12,992 water molecules.

TL;DR: This model reproduces transitions seen in force generation due to changes in pacing that cannot be simulated by previous models and shows improved behavior over existing models that lack detailed descriptions of subcellular Ca2+ regulatory mechanisms.

TL;DR: The results of protein precipitation and crystallization experiments are in qualitative correlation with the patterns of the virial coefficients and demonstrate that interaction mapping could help outline new crystallization regions.

TL;DR: It is shown that kinetic processes can be followed in living cells by monitoring recovery of DHE fluorescence in a photobleached region over time and provided evidence for the presence of a large intracellular cholesterol pool in the endocytic recycling compartment and the trans-Golgi network that might play important roles in the trafficking of lipids, lipid-anchored proteins, and transmembrane proteins that preferentially partition into cholesterol-enriched membrane domains.

TL;DR: Volumetric data and high-resolution synchrotron x-ray data are used in a method that compares DOPC with well determined gel phase dipalmitoylphosphatidylcholine (DPPC) and shows that estimates of the Hamaker parameter H and the bending modulus Kc are strongly coupled.

TL;DR: This work analyzes the free energy cost associated with a hydrophobic mismatch using a (liquid-crystal) elastic model of bilayer deformations and shows that, for a protein embedded in a membrane with an initial hydrophilic mismatch of only 1 A, an increase in hydrophobia to 1.3 A can increase the Boltzmann factor 10-fold due to the elastic properties of the bilayer.

TL;DR: It is suggested that the global analysis of the approach to equilibrium in a short-column sedimentation equilibrium experiment followed by a high-speed short- column sedimentation velocity experiment can result in sedimentation and diffusion coefficients of very high statistical accuracy.

TL;DR: It is reported here that electric field intensity is the deciding parameter inducing membrane permeabilization and controls the extent of the cell surface where the transfer can take place and an increase in the number of pulses enhances the rate of permeabilizations.

TL;DR: This paper compares the unfolding forces of defined regions of different titin isoforms by single-molecule force spectroscopy and indicates that the tightly folded titin domains are designed to maintain their structural integrity, even under the influence of stretching forces.

TL;DR: The out-of-plane distortions of porphyrins in hemoproteins are characterized by displacements along the lowest-frequency out- of-plane normal coordinates of the D4h-symmetric macrocycle, and x-ray crystal structures are analyzed using a computational procedure developed for determining these orthogonal displacements.

TL;DR: The data suggest that detergent solubilization proceeds by a combination of a transbilayer attack, following flip-flop of detergent molecules across the lipid bilayer, and extraction of membrane components directly by detergent micelles.

TL;DR: The results of this study clearly demonstrate that numerical model is reliable and can be very useful in the additional search for electrodes that would make electrochemotherapy and in vivo electroporation in general more efficient and shows that better coverage of tumors with sufficiently high electric field is necessary for improved effectiveness of electroChemotherapy.

TL;DR: The successful prediction of Ca fluxes in this paper demonstrates that ad hoc electrostatic parameters, multiple discrete binding sites, and logistic assumptions of single-file movement are all unnecessary for the prediction of permeation in Ca channels over a wide range of conditions.