CONICET | Buscador de Institutos y Recursos Humanos

Most of the enzymatic processes are carried out in aqueous phase. Nevertheless, there are certain products of commercial interest that cannot be obtained in these media, like the peptide synthesis catalyzed by peptidases. The aim of this communication was to report a stability study of phytopeptidases present in the latex of Araujia hortorum Fourn., for its application to the peptide synthesis in biphasic media formed by 0.1 M Tris-HCl buffer (pH: 8) and organic solvents. An experimental statistical design was carried out by clustering different organic solvents with similar physical-chemistry characteristics. Then, one of each group was selected for stability trials. Peptidases stability assays in 70:30, 50:50 and 30:70 aqueousorganic biphasic media were performed by incubation of crude extract for three hours. Stability profiles of Araujia hortorum peptidases showed that media such as hexane, ethyl ether and dichloroethane (50:50) were lightly activating or they were able to carry on the residual caseinolytic activity, whereas others biphasic media brough forth unactivation. The generalized idea that the more hydrophobic organic solvents are less unactivating than those with log P<4 did not make allowance to explain the behavior of Araujia hortorum peptidases in biphasic media. A qualitative approach to interpret the stability data was carried out by means of physical-chemistry descriptors, extracted from the literature. The correlations obtained were compared with the principal factors that governed the effect of organic solvents on Araujia hortorum peptidases in monophasic media. A comparison with commercial papain under the same experimental conditions (biphasic and monophasic aqueous-organic media), was also carried out.

enviar mensaje