Diffusion effects of bovine serum albumin on cross-linked aggregates of catalase

Publication date: Available online 6 August 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Agnes Cristina Oliveira Mafra, Willian Koop, Maisa Bontorin Beltrame, Raquel de Lima Camargo Giordano, Marcelo Perencin de Arruda Ribeiro, Paulo Waldir Tardioli Stabilization of multimeric enzymes is one of the major challenges in biocatalysis since dissociation of subunits can inactivate the enzyme. Particularly, catalase that breaks down hydrogen peroxide in water and molecular oxygen is an enzyme difficult to stabilize by conventional immobilization techniques, because it is a tetrameric structure containing Fe-protoporphyrin IX in its active site. Cross-linking of enzyme aggregates is a methodology that can overcome this bottleneck, but diffusional delay of mass transport within the particles is a recurrent drawback. In this work, cross-linked aggregates of catalase from bovine liver were prepared, evaluating the influence of precipitant and cross-linking agents, as well as bovine serum albumin (BSA) as feeder protein on the catalytic properties, thermal stability, and mass transport resistance of the derivatives. The most active derivatives were prepared using ammonium sulfate as precipitant agent, 50mM glutaraldehyde as cross-linker, and mass ratio BSA/catalase of 3.0. These derivatives in the absence of diffusive effects showed recovered activity of 98±1.7% and high stability at 40°C and pH 7.0 (∼80% of the initial activity was recovery after 200h ...
Source: Journal of Molecular Catalysis B: Enzymatic - Category: Biochemistry Source Type: research