Estudo de formulações enzimáticas envolvendo β-tripsina bovina com maior atividade e estabilidade em função da concentração de íons para atuação em sistemas de detergentes e saponáceos comerciais

Abstract

Household cleaning is a daily worldwide activity, which means that billions of people use detergents to clean their clothes, dishes, and so forth. The enzymes are increasingly added to achieve "catalytic cleaning", thereby creating smaller fragments of the stain constituents, which in turn facilitates the chemical cleaning action of surfactants. Household detergents are the most important application of industrial enzymes, representing 50% of total sales. Much progress has been made in the last decades in elucidating the structure function relations of enzymes. In this experimental work, we developed a physicochemical study and the biological properties of the bovine β-trypsin isoform related to the concentration of ions that can be used in the formulation of detergents. The enzyme activity of the β-trypsin isoform shown to be influenced by the concentration of cations, but no significant change was observed for anions in the range from 0 to 20 mmol⋅L -1 . For the ionic series of cations, the metallic calcium ion was more effective, but at low concentration from 5 to 10 mmol⋅L -1 , differently from what has been reported in the literature for the interaction of this ion with the enzyme. The monitoring of the effect of the Ca2+ ion on the protein conformation by fluorescence spectroscopy in an acid medium showed that the conformational changes induced in the structure are considered conformational adjustments or small structural adjustments, that not inducing an increase in the fraction of denatured molecules. The thermodynamic analysis of the enzyme system under the influence of the CaCl2 showed that the changes caused by the addition of calcium chloride up to 20 mmol⋅L -1 act mainly on the thermodynamic parameters of cooperativity and heat capacity decreasing both. Furthermore, the addition of calcium ions above the concentration of 5 mmol⋅L -1 has a pronounced effect on protein destabilization. Thus, the typical concentrations of 20 mmol⋅L -1 were destabilizing in both systems tested. Thus, with the determination of the biological and physical-chemical parameters in relation to the enzyme with ions in solution, and mainly the thermodynamics, we can start the second phase of the work that is the formulation of the detergent system with β-trypsin isoform.