Showing papers in "Biophysical Journal in 1978"

TL;DR: The consistency of these calculations supports the conclusion that the most important molecular energies for the main transition in lecithin bilayers are the hydrocarbon chain interactions and the rotational isomeric energies, and that the main phase transition is analogous to the melting transition in the alkanes from the hexagonal phase to the liquid phase, but with some modifications.

TL;DR: The description of the ionic fluxes can be improved by abandoning continuum models in favor of more structured ones and determining how many ions occupy a channel at once and what kind of energy barriers they must cross in traversing the membrane.

TL;DR: The results suggest that the rheological properties of the membrane can undergo dynamic changes depending on the extent and duration of deformation, reflecting molecular rearrangement in response to membrane strain.

TL;DR: The conduction velocity, theta, was found to be quite insensitive to the nodal area or the exact description of its excitable processes, but much more sensitive to the myelin capacitance and axoplasm conductance.

TL;DR: If the fractional increase in capacitance found here is a good approximation to that of biological membranes, nonlinear capacitative charge displacement derived from electrostriction is expected to be less than 1% of the total gating charge displacement found in squid axons.

TL;DR: The electrostatic energy profile of one, two, or three ions in an aqueous channel through a lipid membrane is calculated and the rate of crossing the membrane was estimated and found to be compatible with the maximum conductance observed for the gramicidin A channel.

TL;DR: Support is provided for a direct role of the inactivation gating mechanism in producing the long-lasting use-dependent inhibition brought about by local anesthetic compounds in squid giant axon.

TL;DR: The ability to form bilayers essentially free of the solvent used in the forming solution makes it possible to determine the area per molecule of the surface active lipid in the bilayer.

TL;DR: 3,4-diaminopyridine shows great promise as a useful tool for the study of membrane ionic channels in selectively blocking the potassium channels of squid axon membranes.

TL;DR: Numerical solutions of a set of simplified model equations involving only K+ and Ca++ concentrations exhibit the observed phenomena of solitary waves and annihilation of colliding waves.

TL;DR: It is shown that the absorption of tetraphenylborate into black lipid membranes formed from either bacterial phosphatidylethanolamine or glycerolmonooleate produces concentration-dependent changes in the electrostatic potential between the membrane interior and the bulk aqueous phases.

TL;DR: It is suggested that distortion in the hexagonal lattice below the pretransition temperature previously reported by X-ray diffraction techniques may be responsible for interchain interactions which give rise to a Raman band observed only in the triclinic lattice of even-numbered n-alkanes.

TL;DR: The phase relations in anhydrous mixtures and various methods of preparing aqueous dispersions are analyzed to avoid the formation of metastable states that may be responsible for the variability of the lecithin-cholesterol stoichiometry.

TL;DR: The mechanism for formation of K610 is found to involve a rate-limiting proton transfer which occurs by tunneling at low temperatures.

TL;DR: Stable bend initiation and propagation, without internal viscous resistance, is demonstrated for a flagellum containing a linear elastic bending resistance and an elastic shear resistance that depends on sliding.

TL;DR: The single channel conductances for Li, Na, K, Rb, Cs, H, and Tl and the membrane potentials for Tl-K mixtures are characterized over wider concentration rangers than previously and analyzed using an "equilibrium domain" model that assumes a central rate-determining barrier.

TL;DR: Reconstruction from thick serial transverse slices of frog skeletal muscle fibers stained with peroxidase and examined by high-voltage electron microscopy has revealed that the T system networks at successive sarcomeres are connected together in a helicoidal fashion.

TL;DR: The present results indicate that Transition rates should depend exponentially on membrane potential over a limited voltage range, but probably will show a more complex dependence for extremes of the range.

TL;DR: A theoretical model of the gramicidin A channel is presented and the kinetic behavior of the model is derived and compared with previous experimental results, suggesting that the potential well is located close to the channel mouth and that the conductance is partially limited by the rate going from the bulk solution to the well.

TL;DR: Results support the notion that Na inactivation not only modulates the frequency-dependent block but also involves the voltage-dependent binding reaction between QX-314 and Na channels.

TL;DR: The high gradient magnetic separation technique has been applied to separate paramagnetic erythrocytes from a cell suspension that also contained diamagnetic cells.

TL;DR: The anisotropy of magnetic susceptibility times membrane thickness was calculated from the data for several thin-walled vesicles and the resulting values were assigned to discrete numbers of bilayers.

TL;DR: These measurements provide experimental evidence for the role of cross-relaxation in 1H NMR T1 measurements in proteins, and indicate that cross- Relaxation dominates the T 1 measurements for the larger proteins, even at relatively low resonance frequencies such as 100 MHz.

TL;DR: The results show that UV fluences between 10 and 40 J/m2 produce an average of 21-85 x 10(5) thymine dimers per cell and an eventual maximal loss per cell, which agrees well with reported half-maximal repair synthesis times, which range from 0.5 to 3.6 h based on analysis.

TL;DR: Both relative DNA-stain content and a measure of cell flatness can now be determined simultaneously for each cell at the high rates possible with flow instruments.

TL;DR: A wedge-shaped exit on the sample injection tube in a coaxial flow system is sufficient to produce the desired orientation effect when used with low sample flow rates.

TL;DR: The results indicate that polarization is produced by a radical pair mechanism between P700+ and the reduced primary acceptor of photosystem I, and is due to the g-tensor anisotropy of the acceptor radical to which it is exchange-coupled.

TL;DR: The light-induced short-circuit current generated by a planar membrane containing bacteriorhodopsin incorporated by vesicle fusion is measured and it is proposed that the translocation of protons across the membrane is associated with a first-order process characterized by a rate constant lambda.

TL;DR: From measurements of the equilibrium spreading pressure pie for dispersions of lecithin--dimyristoyl or dioleoyl (DOL)--and cholesterol (CHOL) in water, the phase relations in both the aqueous dispersions and the equilibrium surface films are deduced.