Entalpia de Van’t Hoff e energia livre de Gibbs para associação de tripsina bovina com o íon benzamidínio sob concentrações crescentes de glicerol

Abstract

Osmolytes are a group of low molecular weight solutes that stabilize proteins, nucleic acids, cells, tissues and organs in response to increased environmental stress. They have a ubiquitous distribution, with the same types of solutes being found in very distant organisms on the evolutionary scale. This dissertation initially reviews the main knowledge about the stabilizing effects of osmolytes, with emphasis on protein stabilization, and presents the prevailing ideas in the literature regarding its mechanism of action. Osmolytes force proteins to fold and resist denaturation, altering solvent properties and modifying the interaction of the protein's outer surface with the solvent. Although much work has explored the action of osmolytes on the transition between the native and unfolded states of a protein, little has been studied about the effect of these solutes on the formation of enzyme-inhibitor complexes. This dissertation also studied the effect of glycerol on the inhibition equilibrium of bovine trypsin with benzamidinium ion. Incorporation of 0 to 2.5 mol.L'1 of glycerol does not disturb van't Hoff enthalpy, but increases Gibbs free energy for the association of bovine trypsin with benzamidinium ion.