Showing papers in "Biophysical Chemistry in 1983"

TL;DR: The binding process is shown to be highly cooperative, and it is concluded that the hydrophobic part of the bound surfactant is not completely immersed in the Hydrophobic DNA core, but also interacts with other surfactants molecules.

TL;DR: It was concluded that the antitumor potency of schizophyllan in water is related to the amount of triple helices relative to that of single chains.

TL;DR: A general procedure for simplifying chemical and enzyme reaction kinetics, based on the difference of characteristic time scales, is presented and Korzuhin's Theorem, which makes it possible to approximate any kinetic system by a closed chemical system, is reported.

TL;DR: A lattice theory is proposed to formulate the formation and properties of amphiphilic bilayer membranes and it is shown that they are not narrow, i.e., membrane properties are subject to considerable fluctuations.

TL;DR: The rates of molecular motions in the interior of some proteins were found to scale with an inverse power of the external solvent viscosity, explained by a flexible protein structure whose dynamics is partially controlled by the solvent.

TL;DR: A method for calculation of microscopic protonation constants of polyamines based on data for mono- and diamines gives results for spermidine that agree well with the experimental macroscopic protonated constants and the protonations sequence of Kimberly and Goldstein.

TL;DR: The observations suggest that the experimentally observed linear relations between flows and forces, particularly in the case of oxidative phosphorylation, may be due to a feedback regulation maintaining linear thermodynamic relations far from equilibrium.

TL;DR: The first lifetime measurements of DNA fluorescence are reported and a post-pulse exponentially decaying emission has been observed with a lifetime of 2.9 +/- 0.3 ns; this is most likely an excimer fluorescence.

TL;DR: An artificial membrane was studied consisting of an oil layer, nitrobenzene containing picric acid, imposed between two aqueous phases, and it was found that this system shows rhythmic and sustained oscillation of the electrical potential within the range 150-300 mV with an interval of 2-3 min.

TL;DR: It is proposed that the physical mechanism for this phenomenon involves fluctuations of lipid order induced by fluctuations in protonation of phospholipid head groups within a critical pH range; these, in turn, create conductive defects in the two-dimensional lattice of the lipid bilayer.

TL;DR: It is shown that self-oscillating states, excitable steady states and bistable systems can exhibit the same types of synchronization patterns when submitted to periodic external forces with appropriate amplitude and time scale conditions.

TL;DR: The displacement current is measured in a suspension of electric field-oriented purple membranes isolated from Halobacterium halobium, the photocycle being driven by a light flash, and a simple quantitative theory of the method is presented.

TL;DR: The feasibility of the inclusion of reaction field effects in accurate ab initio self-consistent field-molecular orbital calculations was studied in the case of proton transfer in the active site of actinidin, using the direct reaction field model.

TL;DR: A model is proposed for the monolayer arrangement at the air/water interface which implies two set of dimers of water per molecule of chlorophyll, which could play an important role in the chloroplast.

TL;DR: The results are consistent with the predictions of the theory and show that the diffuse ion atmosphere polarization contributes significantly to the overall orientation of DNA.

TL;DR: The physical significance of the criterion and its relation to the critical spherical shell are substantiated during the process of derivation, which is very helpful for gaining an insight into this kind of biomolecular system with surprisingly high reaction rates.

TL;DR: Bacteriorhodopsin of halobacterial purple membranes exhibits conformational flexibility in high electric field pulses (1-30 x 10(5) V m(-1), 1-100 micros).

TL;DR: The migration of different alkali metal cations through a transmembrane model channel is simulated by means of the molecular dynamics technique and the selectivity sequence for the diffusion rates is the inverse of that expected from normal rate theory but agrees with that found in experiments for gramicidin A.

TL;DR: In this article, the experimental concentration dependence of the weight-average partition coefficient was compared with theoretical expressions, which include considerations of thermodynamic nonideality effects, for the concentration dependence for a single solute and of a solute undergoing reversible self-association.

TL;DR: A general model is developed to simulate dipole-dipole resonance energy transfer in spatially restricted systems and the observed energy transfer from N-(2-naphthyl)-23,24-dinor-5-cholen-22-amide-3 beta-ol to N-dansyldimyristoylphosphatidylcholine bilayer agrees with that predicted by this model

TL;DR: Simulating the convolution of the emission anisotropy decay function with both a delta-pulse excitation function (exact solution) and a pulse function of either Gaussian or other functional form shows that convolution with a pulse of finite width leads to lower r0 values.

TL;DR: Simple analytic expressions are well suited for predicting trends in the ionic conductivity of protein channels on the basis of microscopic interactions, and the results are in good agreement with experimental data and data from computer simulations.

TL;DR: The analysis reported confirms the applicability of the Monod-Wyman-Changeux two-state allosteric model to P. interruptus hemocyanin and yields a complete thermodynamic characterization of oxygen binding under both equilibrium and dynamic regimes.

TL;DR: From the proposed model, it is possible to account for the influence of the addition of Ca2+ on the single-channel limiting conductance and on the variation of thesingle-channel current as a function of the voltage in the presence of Cs or K+.

TL;DR: A new excess free energy term in the state function is constructed to describe the thermodynamic properties of the two-component phospholipid bilayers where the chain lengths and the polar heads of the components can be different simultaneously.

TL;DR: The interaction between polyacrylate ion and Cu2+, Zn2+ or Mn2+ includes a specific interaction with bond formation, whereas in the case of Mg2+ and Ba2+, the electrostatic interaction is dominant.

TL;DR: The results show that 23Na-NMR line widths for the counterions are determined nearly exclusively by Na+ in the immediate vicinity of the linear polyelectrolyte, suggesting that two-state treatments, despite their crude character, can reproduce such experimental data rather well.

TL;DR: The emission spectrum of intact purple membranes of Halobacterium halobium has a very short wavelength position and can be fitted by two spectral components, one of which corresponds to the fluorescence of buried tryptophan residues located in a highly hydrophobic rigid environment.

TL;DR: The specific orientation of chlorpromazine molecules in a liquid membrane with hydrophobic ends facing the permeable substances has been found to reduce the permeability of catecholamines and neurotransmitter amino acids.

TL;DR: The selective rate was shown to be particularly sensitive in detecting binding interactions with macromolecular cell constituents and it was shown that the aromatic moiety of procaine is involved in binding the cell plasma membrane.