A calorimetric investigation for the bindings of mushroom tyrosinase to p-phenylene-bis dithiocarbamate and xanthates

A comprehensive, simple and rapid thermodynamic study on the interaction of Mushroom Tyrosinase, MT, with three iso-alkyldithiocarbonates (xanthates), as sodium salts, C3H7OCS2Na (I), C4H9OCS2Na (II), C5H11OCS2Na (III) and p-phenylene-bis dithiocarbamate (IV), by using isothermal titration calorimetry was carried out to clarify thermodynamics of these bindings as well as structural changes of the enzyme due to its interaction with inhibitors at 300K in phosphate buffer (10 m molL-1; pH 6.8).The extended solvation theory was used to elucidate the effect of the inhibitors on the stability of enzyme. The obtained results indicate that there are two identical and non-cooperative binding sites for these inhibitors.