Surface functionalization of chitosan-coated magnetic nanoparticles for covalent immobilization of yeast alcohol dehydrogenase from Saccharomyces cerevisiae

Akduman

Journal of Biomaterials Science, Polymer Edition

et al. 2015

In this presented work, poly(HEMA-GMA) cryogel was synthesized and used for the immobilization of alcohol dehydrogenase. For this, synthesized cryogels were functionalized with iminodiacetic acid and chelated with Zn(2+). This metal-chelated cryogels were used for the alcohol dehydrogenase immobilization and their kinetic parameters were compared with free enzyme. Optimum pH was found to be 7.0 for both immobilized and free enzyme preparations, while temperature optima for free and immobilized alcohol dehydrogenase was 25 °C. Kinetic constants such as K(m), V(max), and k(cat) for free and immobilized form of alcohol dehydrogenase were also investigated. k(cat) value of free enzyme was found to be 3743.9 min(-1), while k(cat) for immobilized enzyme was 3165.7 min(-1). Thermal stability of the free and immobilized alcohol dehydrogenase was studied and stability of the immobilized enzyme was found to be higher than free form. Also, operational stability and reusability profile of the immobilized alcohol dehydrogenase were investigated. Finally, storage stability of the free and immobilized alcohol dehydrogenase was studied, and at the end of the 60 days storage, it was demonstrated that, immobilized alcohol dehydrogenase was exhibited high stability than that of free enzyme.

Section: Resultssupporting

confidence: 91%

Immobilization of alcohol dehydrogenase onto metal-chelated cryogels

Akduman

Journal of Biomaterials Science, Polymer Edition

et al. 2015

Micro and Nanotechnologies for Biotechnology

“…Also used as coatings are different polymers, such as polyethylene glycol (PEG), polyvinylpyrroline (PVP), and polyvinyl alcohol (PVA). More importantly, also natural materials, such as chitin, dextran, alginate, albumin, gelatin, starch, liposomes, and ethyl cellulose, are widely used and applied as coatings onto iron oxide magnetic nanoparticles, which are bound chemically or by multiple hydrogen bonds and therefore develop hydrophilic system [69][70][71][72][73][74][75]. Coatings on iron magnetic nanoparticles do not only influence the colloidal stability but also the biological functionality of nanoparticles.…”

Section: Magnetic Nanoparticles As Nanocarriersmentioning

confidence: 99%

Micro‐ and Nanocarriers for Immobilization of Enzymes

Leitgeb¹,

Knez²,

Vasić³

2016

Two types of micro-and nanocarriers for immobilization of enzymes for biotechnological and biomedical applications are described: magnetic nanoparticles and crosslinked enzyme aggregates (CLEAs). Nanosized structures with their large surface and smaller size volume ratio, which is dependent on their strong magnetic dipole, give key features that make magnetic nanoparticles useful in many biotechnological and biomedical applications. They are therefore used as carriers to which different active substances can bind. The preparation of the magnetic nanoparticles, possible surface coating methods, and functionalization with different materials are described. Enzyme immobilization methods, such as adsorption, affinity binding, chelation, or metal binding or covalent binding, enable the preparation of efficient and stable enzyme bound to magnetic nanoparticles. Such a product may be used among bioreactor applications for targeted drug delivery in biosensors or bioimaging and magnetic resonance imaging. Preparation of CLEAs, the microsized enzyme structures without a carrier, is described as well. Their main advantage is very simple preparation, where two steps, precipitation of the enzyme and cross-linking, are joined. A broad spectrum of enzymes for CLEA preparation has been used and many biotechnological reactions are catalyzed. The improvement in CLEA preparation to enhance their stability and operability is also shown.

“…Usually, enzyme immobilization onto magnetic nanoparticles can be obtained by three methods: physical adsorption, entrapment and covalent attachement [4,[28][29][30][31]. Various enzymes such as lipase [32], α-amylase [33], laccase [34], β-D-galactosidase [35] or alcohol dehydrogenase [36] were immobilized onto MNP via physical adsorption, but the obtained enzyme preparations were characterized by reduced reusability [37]. When physical entrapment occurs, more stable biocatalysts were obtained, the enzymatic activity was usually maintained, but the performance of these biocatalysts was often affected by both the diffusion barrier and enzyme leakage [4,28,29].…”

Section: Introductionmentioning

confidence: 99%

Efficient and Stable Magnetic Chitosan-Lipase B from Candida Antarctica Bioconjugates in the Enzymatic Kinetic Resolution of Racemic Heteroarylethanols

et al. 2020

Lipase B from Candida antarctica immobilized by covalent binding on sebacoyl-activated chitosan-coated magnetic nanoparticles proved to be an efficient biocatalyst (49.2–50% conversion in 3–16 h and >96% enantiomeric excess) for the enzymatic kinetic resolution of some racemic heteroarylethanols through transesterification with vinyl acetate. Under optimal conditions (vinyl acetate, n-hexane, 45 °C), the biocatalyst remains active after 10 cycles.