This work aimed to study the structural features and mechanisms of thermoinactivation hyperthermophilic L-asparaginase (L-ASNase) from archaea Thermococcus sibiricus (TsA) in comparison with bacterial L-ASNases Melioribacter roseus (MrA) Rhodospirillum rubrum (RrA). The catalytic parameters L-asparagine hydrolysis under optimal conditions (pH 9) were determined for these enzymes by circular dic...

The interaction between single-stranded RNAs and liposomes was studied using UV, Fourier Transform Infrared spectroscopy (FTIR) and Circular Dichroism spectroscopy (CD). The effect of the surface characteristics of liposomes, which were composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and modified with cholesterol (Ch) or 1,2-dioleoyl-3-trimethylammonium propane (DOTAP), on t...

Binding and proximity relationships of hydrophobic ligands on human serum albumin have been studied using absorption, fluorescence, circular dichroism, and electron paramagnetic resonance spectroscopy. The ligands studied were bilirubin, two conjugated linear polyene fatty acids, cis-parinaric acid and cis-eleostearic acid, and three nitroxide derivatives of stearic acid with doxyl groups at po...

We have evaluated the ability of nuclear magnetic resonance (NMR) and circular dichroism (CD) spectroscopies to describe the difference in the folding propensities of two structurally highly similar cyclic β-hairpins, comparing the outcome to that of molecular dynamics simulations. NAMFIS-type NMR ensemble analysis and CD spectroscopy were observed to accurately describe the consequence of alte...

human serum albumin (hsa) is an abundant, multifunctional and nonglycosylated negatively charged plasma protein. hsa ascribed ligand-binding and transport properties, antioxidant functions and enzymatic activities. in the present study, the interaction and side effects of a new designed anti-cancer compound (1,10-phenanthroline butyl dithiocarbamato palladium(ii) nitrate) on hsa have been inves...

Objective: To study the role of peroxynitrite-modified human serum albumin (nitroxidized-albumin) in rheumatoid arthritis. Methods: Human serum albumin was exposed to peroxynitrite and changes in albumin structure were monitored by UV-visible, fluorescence and circular dichroism spectroscopy, thioflavin T, Congo red binding and attenuated total reflection-Fourier transformed infrared spectrosco...

Fluorescence quenching is an interesting phenomenon which is highly useful in developing fluorescence based sensors. A thorough understanding of the fluorescence quenching mechanism is essential to develop efficient sensors. In this work, we investigate different aspects governing the nitrite ion-induced fluorescence quenching of luminescent bovine serum albumin stabilized gold nanoclusters (BS...

Complexation of chlorogenic acid (CA) by b-cyclodextrin (b-CD) at mildly acidic pH, was studied by fluorescence spectroscopy, isothermal titration calorimetry (ITC), cyclic voltammetry (CV) and NMR spectroscopy. Thermodynamic parameters (DH°, DS° and K) determined by both fluorescence and ITC, showed that the complexation of CA by b-CD is an enthalpy-driven process. Results show that CA molecul...

Interactions of three new isophorone derivatives, Isoa Isob and Isoc with salmon testes DNA have been investigated using UV-Vis, fluorescence and circular dichroism spectroscopic methods. All the studied compounds interact with DNA through intercalative binding mode. The stoichiometry of the isophorone/DNA adducts was found to be 1:1. The fluorescence quenching data revealed a binding interacti...