a thermodynamic study of copper ions by jack bean urease (jbu) was carried out at two temperatures of 27 and 37?c in tris buffer (30 mm; ph=7.0) using an isothermal titration calorimetry. there is a set of twelve identical and non-interacting binding sites for copper ions. the intrinsic dissociation equilibrium constant and the molar enthalpy of binding are 285 µm and ?15.2 kj/mol at 27?c and 3...

In this paper we show that hydroxyapatite nanoparticles (NP) can not only act as a chaperon (by imparting thermostability) but can serve as a synthetic enhancer of activity of an isolated extracellular pectate lyase (APL) with low native state activity. The purified enzyme (an attenuated strain of Macrophomina phaseolina) showed feeble activity at 50°C and pH 5.6. However, on addition of 10.5 µ...

Magnetic skyrmions are topologically protected whirls that decay through singular magnetic configurations known as Bloch points. We used Lorentz transmission electron microscopy to infer the energetics associated with the topological decay of magnetic skyrmions far from equilibrium in the chiral magnet Fe1-x Co x Si. We observed that the lifetime τ of the skyrmions depends exponentially on temp...

The partition coefficients (Kps) of phenothiazine drugs (trifluoperazine, triflupromazine, chlorpromazine and promazine) between phosphatidylcholine (PC) small unilamellar vesicles (SUV) and water were determined over the temperature range of 10-40 degrees C by a second-derivative spectrophotometric method. The second derivative spectra of each drug solution containing various amounts of SUV sh...

To investigate the role of Vernier zone residues, which are comprised in the framework regions and underlie the complementarity-determining regions (CDRs) of antibodies, in the specific, high affinity interactions of antibodies with their targets, we focused on the variable domain fragment of murine anti-human epidermal growth factor receptor antibody 528 (m528Fv). Grafting of the CDRs of m528F...

The structure and dynamics of enigmatic hexa(3,5-di-tert-butylphenyl)ethane was characterized via NMR spectroscopy for the first time. Our variable temperature NMR analysis demonstrates an enthalpy-entropy compensation that results in a vanishingly low dissociation energy (ΔG298d = -1.60(6) kcal mol-1). An in silico study of increasingly larger all-meta alkyl substituted hexaphenylethane deriva...

The structure and dynamics of enigmatic hexa(3,5-di-tert-butylphenyl)ethane was characterized via NMR spectroscopy for the first time. Our variable temperature NMR analysis demonstrates an enthalpy– entropy compensation that results in a vanishingly low dissociation energy (DG d 1⁄4 1.60(6) kcal mol ). An in silico study of increasingly larger all-meta alkyl substituted hexaphenylethane derivat...

the interaction between isatin-β-thiosemicarbazone (ibt) and calf thymus dna (ct-dna) was investigated in physiological buffer (ph 7.4) using neutral red (nr) dye as a spectral probe by uv–vis absorption and fluorescence spectroscopy, as well as viscosity measurements. the ibt is stabilized by intercalation in the dna ( k [ibt –dna] =1.03×105 m−1), and displaces the nr dye from the nr–dna comple...

the interaction of fe2+ ion with pyrazole was theoretically studied by gussian 03, software at hf/(lanl2dz+6-31g) and hf/ (lanl2dz+6-31g (d)) levels in gas phase and solution. in this study acompartion between optimized structures of pyrazole molecule in aspect of thermodynamicparameters such as enthalpy (h°), gibbs free energy (g°) and entropy (s°) in presence of metallic ion(fe2+), was perfor...