A critical review of the estimation of the thermodynamic parameters on adsorption equilibria. Wrong use of equilibrium constant in the Van't Hoof equation for calculation of thermodynamic parameters of adsorption

Enhanced dyes adsorption from wastewater via Fe3O4 nanoparticles functionalized activated carbon.

Structural alterations of albumin, their dependence on concentration and the role of free --SH groups at thermal denaturation, as well as the reversibility of thermally induced structural changes, were studied. Application of various physical methods provides information on a series of structural parameters in a major concentration range. Apart from changes of the helix content, heat treatment gives rise to beta structures which are amplified on cooling and which are correlated with the aggregation of albumin. With rising temperature and concentration the proportion of beta structures and aggregates increases. At degrees of denaturation of up to 20% complete renaturation is possibly in every case. The structure content is concentration-dependent even at room temperature. It may be that intermolecular interactions induce additional alpha-helix structures which are less stable, however, than the ones stabilized by intramolecular interactions. Unfolding of the pocket containing the free --SH group of cysteine-34 enables disulphide bridges to be formed leading to stable aggregates and irreversible structural alterations. Through binding of N-ethymaleimide to free --SH groups, which blocks the formation of disulphide bridges, it is possible to prevent aggregation and irreversible conformational changes. At temperatures below 65--70 degrees C, oligomers are formed mainly via intermolecular beta structures.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1432-1033.1980.tb04449.x

Temperature Behaviour of Human Serum Albumin

Carbohelicenes and heterohelicenes

Excited-state interactions between chlorophyll a (Chla) and gold nanoparticles have been studied. The emission intensity of Chla is quenched by gold nanoparticles. The dominant process for this que...

Photoinduced Electron Transfer between Chlorophyll a and Gold Nanoparticles

Introduction and Gas Laws Kinetic Theory of Gases The First Law of Thermodynamics The Second Law of Thermodynamics Gibbs and Helmholtz Energies Nonelectrolyte Solutions Electrolyte Solutions Chemical Equilibrium Electrochemistry Quantum Mechanics Application of Quantum Mechanics to Spectroscopy Electronic Structure of Atoms Molecular Electronic Structure and the Chemical Bond Electronic Spectroscopy and Magnetic Resonance Spectroscopy Photochemistry Chemical Kinetics Intermolecular Forces The Solid State The Liquid State Statistical Thermodynamics Appendices Glossary Answers to Even-Numbered Computational Problems Index

Physical Chemistry for the Chemical Sciences

On the location of the sulfhydryl group in bovine plasma albumin

— The quenching of chlorophyll a excited singlet states by 2.5-dimethyl-p-benzoquinone has been investigated in solvents of varying viscosity and polarity. The observed singlet lifetimes showed little variation in several hydrocarbon solvents. Stern-Volmer constant K depends on the viscosity of the solvent, although cyclic and straight-chain hydrocarbons behave somewhat differently. The decrease of the K values with increase of viscosity suggests that the quenching mechanism is at least partly dynamic, although there is evidence for static quenching as well. The influence of solvent polarity on the K values was found to be insignificant, which is consistent with a very short-lived ion pair intermediate formed by electron-transfer quenching.

Raymond Chang

Papers

Physical Chemistry for the Chemical Sciences

On the location of the sulfhydryl group in bovine plasma albumin

SOLVENT INFLUENCES ON THE SINGLET QUENCHING OF CHLOROPHYLL a BY 2, 5-DIMETHYL-p-BENZOQUINONE

The environment of the sulfhydryl group in human plasma albumin as determined by spin labeling.

Protodediazoniation of Aryldiazonium Fluoroborates by Dimethylformamide [1]