RESUMEN
The features of brucine (BC) binding to two blood proteins, bovine hemoglobin (BHb), and bovine serum albumin (BSA), were investigated via fluorescence, circular dichroism and UV/Vis absorption spectroscopy. The results revealed that BC caused the fluorescence quenching of blood proteins by the formation of BC-protein complex. The corresponding thermodynamic parameters were measured at different temperatures. The process of binding BC molecule on protein was a spontaneous molecular interaction procedure in which entropy increased and Gibbs free energy decreased. Hydrophobic and electrostatic interactions play a major role in stabilizing the complex. The molecular docking has been employed to explore the binding site of the BC in BHb and BSA on the Autodock 4.2. The distances r between BC and protein were calculated to be 4.93 and 5.08 nm for BHb, and BSA, respectively. The effect of BC on the conformation of blood proteins was analyzed using CD, synchronous fluorescence and three-dimensional fluorescence spectra.
Asunto(s)
Proteínas Sanguíneas/metabolismo , Estricnina/análogos & derivados , Animales , Sitios de Unión , Proteínas Sanguíneas/química , Bovinos , Dicroismo Circular , Transferencia de Energía , Hemoglobinas/química , Hemoglobinas/metabolismo , Concentración de Iones de Hidrógeno , Cinética , Estructura Secundaria de Proteína , Albúmina Sérica Bovina/química , Albúmina Sérica Bovina/metabolismo , Espectrometría de Fluorescencia , Espectrofotometría Ultravioleta , Estricnina/química , Estricnina/metabolismo , TermodinámicaRESUMEN
The dynamic adsorption of trichloroethylene (TCE), 1,2-dichloroethane (DCE) and trichloromethane (TCM) vapors onto hydrophobic hypercrosslinked polymeric resin (LC-1) were investigated using the fixed-bed adsorption method. The results indicated that the breakthrough time decreased and the height of mass transfer zone increased with the elevated initial concentration, gas flow rate and adsorption temperature. The gas flow rate had the wost significant influence on breakthrough time and height of mass transfer zone among the three factors. In addition, a simple semi-empirical mathematic model developed by Yoon and Nelson was applied to investigate the breakthrough behavior, and all correlation coefficients R2 were greater than 0.994.
Asunto(s)
Contaminantes Atmosféricos/aislamiento & purificación , Hidrocarburos Clorados/aislamiento & purificación , Resinas Sintéticas/química , Adsorción , Reactivos de Enlaces Cruzados , Polímeros , VolatilizaciónRESUMEN
The interaction between silicotungstic acid and bovine serum albumin (BSA) was investigated using fluorescence and UV/vis. The experimental results showed that the fluorescence quenching of BSA by silicotungstic acid is a result of the formation of SiW-BSA complex; static quenching and non-radiative energy transferring were confirmed to result in the fluorescence quenching. The binding site number n, apparent binding constant K(A) and corresponding thermodynamic parameters were measured at different temperatures. The process of binding SiW molecule on BSA was a spontaneous molecular interaction procedure in which entropy increased and Gibbs free energy decreased. Hydrophobic interaction force plays a major role in stabilizing the complex. The effect of silicotungstic acid on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy.