engleski

Biocatalyst improvement of halohydrin dehalogenase

Halohydrin dehalogenases (HHDHs) are important and versatile biocatalysts, that can be used for the synthesis of important building blocks and precursors in the pharmaceutical, agrochemical and chemical industries. HHDHs have a wide spectrum of different compounds, such as chiral epoxides, β-substituted alcohols, oxazolidinones and others, that can be synthesized by their action. However, the enzyme was reported to lack stability under operational conditions. Therefore, immobilization of HHDH onto magnetic nanoparticles (MNPs) represents a powerful tool to overcome its limitations and improve its enzyme characteristics as a biocatalyst. HHDH was immobilized onto bare maghemite nanoparticles, chitosan coated MNPs and carboxymethyl dextran (CMD) coated MNPs. All types of MNPs were prepared by co-precipitation method of ferrous and ferric ions. The immobilization protocol was initially optimized using 10% (v/v) cross-linker glutaraldehyde (GA) in order to improve residual activity and immobilization efficiency of immobilized HHDH. The highest immobilization efficiency (91%) of immobilized HHDH was achieved, while using CMD coated MNPs, which were cross-linked with 10% (v/v) GA for 1 hour at 350 rpm and later immobilized with HHDH for 1 hour at 350 rpm. To implement HHDH at industrial scale, initial optimization of HHDH immobilization was performed, which offers room for improvement in order to achieve an effective biocatalyst for various synthetic applications.

halohydrin dehalogenase ; magnetic nanoparticles ; functionalization ; immobilization ; cross-linking

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