Effect of protein load on stability of immobilized enzymes

Publication date: Available online 16 December 2016 Source:Enzyme and Microbial Technology Author(s): Laura Fernandez-Lopez, Sara G. Pedrero, Nerea Lopez-Carrobles, Beatriz C. Gorines, Jose J. Virgen-Ortíz, Roberto Fernandez-Lafuente Different lipases have been immobilized on octyl agarose beads at 1mg/g and at maximum loading, via physical interfacial activation versus the octyl layer on the support. The stability of the preparations was analyzed. Most biocatalysts had the expected result: the apparent stability increased using the highly loaded preparations, due to the diffusional limitations that reduced the initial observed activity. However, lipase B from Candida antarctica (CALB) was significantly more stable using the lowly loaded preparation than the maximum loaded one. This negative effect of the enzyme crowding on enzyme stability was found in inactivations at pH 5, 7 or 9, but not in inactivations in the presence of organic solvents. The immobilization using ethanol to reduce the immobilization rate had not effect on the stability of the lowly loaded preparation, while the highly loaded enzyme biocatalysts increased their stabilities, becoming very similar to that of the lowly loaded preparation. Results suggested that CALB molecules immobilized on octyl agarose may be closely packed together due to the high immobilization rate and this produced some negative interactions between immobilized enzyme molecules during enzyme thermal inactivation. Slowing-down...

Source: Enzyme and Microbial Technology - December 16, 2016 Category: Biotechnology Source Type: research