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...

Kinetic and thermodynamic studies have been made on the effect of the inosine product on the activity of adenosine deaminase in a 50 mM sodium phosphate buffer, pH 7.5, at 27 degrees C using UV spectrophotometry and isothermal titration calorimetry (ITC). A competitive inhibition was observed for inosine as a product of the enzymatic reaction. A graphical-fitting method was used for determinati...

Cooperative binding pervades Nature. This review discusses the use of isothermal titration calorimetry (ITC) in the identification and characterisation of cooperativity in biological interactions. ITC has broad scope in the analysis of cooperativity as it determines binding stiochiometries, affinities and thermodynamic parameters, including enthalpy and entropy in a single experiment. Examples ...

Isothermal titration calorimetry (ITC) has become a standard method for investigating the binding of ligands to receptor molecules or the partitioning of solutes between water and lipid vesicles. Accordingly, solutes are mixed with membranes (or ligands with receptors), and the subsequent heats of incorporation (or binding) are measured. In this paper we derive a general formula for modeling IT...

Kinetic and thermodynamic studies were made on the effect of caffeine on the activity of adenosine deaminase in 50 mM sodium phosphate buffer, pH 7.5, using UV spectrophotometry and isothermal titration calorimetry (ITC). An uncompetitive inhibition was observed for caffeine. A graphical fitting method was used for determination of binding constant and enthalpy of inhibitor binding by using iso...

The interaction of biologicalmacromolecules, whether protein-DNA, antibody-antigen, hormone-receptor, etc., illustrates the complexity and diversity of molecular recognition. The importance of such interactions in the immune response, signal transduction cascades, and gene expression cannot be overstated. It is of great interest to determine the nature of the forces that stabilize the interacti...

Isothermal titration calorimetry (ITC) is a technique used to determine the thermodynamic properties of a chemical or physical equilibria. While the most abundant applications lie in the field of biochemical characterization, its use has increased in other fields because of minimal sample and buffer restrictions. The foundation of this technique is based on the simple measurement of heat, q. Be...