RESUMEN
The physicochemical and enzymatic properties of hybrid analogues of the Brevundimonas diminuta Gl7ACA-acylase (BrdGIA), containing the N-terminal chitin-binding domain of the bacterial chitinase (BrdG1A/NmChBD) or the C-terminal oligohistidine sequence (BrdGIA/H), were studied. An enhanced thermostability level of BrdG1A/NmChBD could suggest the stabilizing effect of the chitin-binding domain. An analysis of pH profiles of the enzymatic activity of recombinat BrdGIA analogues did not reveal significant differences: the catalytic activity of both variants changed slightly in the.interval ofpH values from 6.0 to 9.0 but drastically decreased at lower pH values. Both analogues demonstrated similar sensitivity towards denaturing agents: addition of 2.0 M ofguanidine chloride resulted in the complete inactivation of both enzymes. A scheme was developed for obtaining isolated recombinant alpha- and beta-subunits of BrdGLA. In vitro enzyme reconstructions indicated that the alpha-subunit was necessary for the formation of a correct spatial structure of the beta-subunit and for the formation of a functionally active enzyme.