Structure-Performance Relationships of Lipolytic Enzymes Immobilized on Polymeric Nanoparticles

The intersection between biotechnology and nanotechnology is opening the way to the development of hybrid materials, that can sum the catalytic and highly selective recognition properties of biological molecules to the peculiar characteristics of nanoparticles. Moreover, we have evidenced that polylactic acid (PDLLA) nanoparticles can influence Candida rugosa lipase (CRL) catalytic performance, enhancing dramatically its activity in aqueous medium [1]. PDLLA was processed using an innovative patented methodology [2] that permitted to obtain spherical nanoparticles with a mean diameter of 200 nm, that were used as carrier for the physical adsorption of CRL preparations. Enzymatic activity and stability before and after conjugation to the nanopolymeric support were evaluated in different conditions (pH, T, organic solvents), evidencing the higher specific activity and stability to denaturing agents of the bioconjugates. FTIR characterization of free and immobilized enzymes showed a reproducible modification in the conformational features of CRL in different media (solid state and aqueous solutions). In an attempt to assess the structure-performance relationship of the immobilized CRL, based on biochemical studies and FTIR characterization, we propose that the enhancement of the enzyme performance is closely related to the conformational changes of the protein structure due to the immobilization on nanocarriers.