Application of a simple calorimetric data analysis on the binding study of cyanide ions by Jack bean urease

Cyanide ion was studied as an effector of Jack bean urease（JBU） at 300 K in 30 mmol/LTris buffer,pH 7 by isothermal titration calorimetry（ITC）.The simple novel model was used for CN;+ JBU interaction over the whole range of CN;concentrations.The binding parameters recovered from the simple novel model were attributed to the cyanide ion interaction.It was found that cyanide ion acted as a noncooperative inhibitor of JBU,and there is a set of 12 identical and independent binding sites for CN;ions.The dissociation equilibrium constant is 750μmol/L.The molar enthalpy of binding is△H= -13.6 kJ mol;.The technique used provided an accurate and quick assessment of the effectiveness of the compounds to inhibit Jack bean urease.