Showing papers in "Biophysical Journal in 1993"

TL;DR: In this article, the authors discuss the basic quantitative features of the observed BOLD-based signal changes, including the signal amplitude and its magnetic field dependence and dynamic effects such as a pronounced oscillatory pattern that is induced in the signal from primary visual cortex during photic stimulation experiments.

TL;DR: In this article, the trajectories of E-cadherin, epidermal growth factor receptor, and transferrin receptor in the plasma membrane of a cultured mouse keratinocyte cell line were studied using both single particle tracking (SPT; nanovid microscopy) and fluorescence photobleaching recovery (FPR).

TL;DR: A model for how chemical reactions generate protrusive forces by rectifying Brownian motion is presented, which drives a number of intracellular processes, including filopodial protrusion, propulsion of the bacterium Listeria, and protein translocation.

TL;DR: In this paper, equilibrium titrations and kinetic experiments were used to define the cooperative binding of myosin subfragment 1 (S1) to actin-troponinintropomyosin.

TL;DR: The ability of a particular additive to preserved the aqueous structure of dehydrated proteins and poly-L-lysine upon dehydration correlates directly with its ability to preserve the activity of lactate dehydrogenase, a labile enzyme, during drying.

TL;DR: A new method is developed to analyze and display the pore dimensions of ion channels using two x-ray crystal structures of gramicidin that adopt distinct antiparallel double helical dimer conformations and a nuclear magnetic resonance (NMR) structure for the beta6.3 NH2-terminal to NH2 -terminal dimer.

TL;DR: Force modulation and phase sensitive detection was used to image soft surfaces with the atomic force microscope, allowing the simultaneous recording of images of the surface profile, the storage modulus, and the loss modulus of the sample.

TL;DR: The present work demonstrates the underlying theory, showing how the principles can be applied to measurements on standard fluorescent beads and changes in distribution of receptors for platelet-derived growth factor on human foreskin fibroblasts.

TL;DR: The calcium binding capacity of bovine chromaffin cells preloaded with fura‐2 was measured during nystatin‐perforated‐patch recordings and it was found that cellular autofluorescence and contributions to fluorescence of non‐hydrolysed or compartmentalized dye contribute a serious error in estimation of kappa S.

TL;DR: In this paper, the authors estimate the lipid composition-dependent free energies of intermediate structures of different geometries, and then infer which fusion mechanism is the best explanation of observed behavior in different systems by selecting the mechanism that requires the least energy.

TL;DR: The critical membrane potential difference which induces membrane permeabilization can be calculated and it is observed that its value is always about 200 mV for many different cell systems as previously reported in the case of pure lipid vesicles.

TL;DR: A relationship between DNA melting and aggregation is proposed in which initial metal binding at major groove sites locally destabilizes the B-DNA double helix, causing displacement of the bases away from one another and exposing additional metal binding sites.

TL;DR: The fact that both MSCs were functional in liposomes following chromatography strongly suggests that these channels are gated by tension transduced via lipid bilayer, and chromatographic fractionation of detergent-solubilized membrane proteins with subsequent patch sampling of reconstituted fractions can be used to identify and isolate these MS channel proteins.

TL;DR: The model serves to capture the essential macroscopic mechanisms that are involved in the production of intracellular Ca2+ oscillations and traveling waves in the Xenopus laevis oocyte.

TL;DR: Changes in the membrane conductance of sea urchin eggs, during the course of electroporation, were investigated over the time range of 0.5 microsecond to 1 ms by imaging the transmembrane potential at a submicrosecond resolution with the voltage-sensitive fluorescent dye RH292.

TL;DR: Measurements of the asymmetry of obstructed and unobstructed random walks are calculated, and probabilities are evaluated for random trajectories that resemble either directed motion or diffusion in a bounded region.

TL;DR: Values of area per lipid A ranging from 56 to 72 A 2 have been reported from essentially the same SCD data from DPPC in the L alpha phase, but the differences are due primarily to three separate binary choices in interpretation.

TL;DR: The analysis of the fiber x-ray patterns from beta/A4 peptides shows the organization of the beta-crystallites that form the wall of the amyloid fibrils as well as possible side-chain interactions.

TL;DR: The Boundary Element Method is presented and benchmarked with existing Slender Body Theory results and reflection solutions for the motion of spheres and slender bodies near plane boundaries to model the swimming of a microorganism with a spherical cell body, propelled by a single rotating flagellum.

TL;DR: The method uses a precisely defined source of fluorescent molecules pressure ejected from a micropipette, and a detailed theory of the intensity contributions from out-of-focus molecules in a three-dimensional medium to a two-dimensional image to validate the method.

TL;DR: A correlation between measured Ro and the relative probabilities of different conductance states is observed, which suggests states of higher conductance are more probable in dioleoylphosphatidylethanolamine, the lipid of highest curvature, 1/Ro, than indioleOYlph phosphatidylcholine, the cholesterol of lowest curvature.

TL;DR: In this article, the authors investigated the structural role of the endosarcomeric lattices of a rabbit psoas muscle fiber with respect to the relative immunoelectron microscopy of the elastic titin filaments.

TL;DR: The results provide evidence that coat proteins are not necessary for budding and fission of vesicles and the physics of the lipid bilayer is rich enough to explain the observed behavior.

TL;DR: A computer model is developed that predicts the bundling threshold based on four variables: the length of the actin filaments, the affinity of the alpha-actinin for actin, the concentrations of actin and alpha- actinin.

TL;DR: In this paper, the polymerization of protein subunits into precursor shells empty of DNA is a critical process in the assembly of double-stranded DNA viruses, and the morphology of these intermediates suggests that assembly is a highly directed process.

TL;DR: The tilt angle theta tilt of the hydrocarbon chains has been determined for fully hydrated gel phase of a series of saturated lecithins and it is suggested that the headgroup packing is at its excluded volume limit for this range.

TL;DR: It is concluded that the level of resting myoplasmic free Ca2+ in frog fibers is at least 0.1 microM and possibly as large as 0.3 microM, which lies near the upper end of the range of values for [Ca2+]r in frog fiber values estimated by others with aequorin and Ca(2+)-selective electrodes.

TL;DR: Rolling adhesion of PMNs on histamine-stimulated HUVECs appears to be completely dependent on endothelial cell P-selectin, with a minor adhesion-stabilizing contribution from intercellular adhesion molecule 1 and beta 2 integrins.

TL;DR: Techniques for rapid, high resolution, quantitative three-dimensional imaging microscopy and mathematical modeling are combined to determine accurate distributions of a potentiometric fluorescent probe between the cytosol and individual mitochondria inside a living cell.

TL;DR: Qualitative interpretations of the interaction free energy between a hydrophobic, transmembrane, protein and the surrounding lipid environment are supported by detailed numerical calculations of the various contributions to the interactionfree energy, and of chain conformational properties.