Preparation and properties of invertase immobilized on a poly(maleic anhydride-hexen-1) membrane

Abstract

Poly(maleic anhydride-alt-hexen-1)(poly(MA-alt-H-1)) has been synthesized by radical polymerization and characterized by DSC, FT-IR, acid number determination, viscometric and NMR methods. Data showed that the co-polymer is an alternating co-polymer whose composition does not depend on the monomer feed composition. Invertase was immobilized onto a poly(MA-alt-H-1) membrane via glutaraldehyde and bovine serum albumin. The Km value of poly(MA-alt-H-1)-invertase was approximately 4.4-fold higher than the free enzyme, indicating decreased affinity by the invertase for its substrate (sucrose), whereas Vmax was lower for the immobilized invertase. Immobilization improved the pH stability of the enzyme, as well as its temperature stability. Immobilized samples obtained were stable and could be used many times over a period of 2 months without considerable activity loss.

DFT Modeling of the Alternating Radical Copolymerization and Alder-Ene Reaction between Maleic Anhydride and Olefins

“…The formation of 1,4-butylene fragments can therefore complicate MA-ethylene copolymerization under the high ethylene pressure. The result of the calculations are in agreement with early published data on the copolymerization of MA with different olefins [3,4,9,13,83,84], in particular, with low reactivity of 2-butenes and full inertness of TME towards MA in the presence of free-radical initiators [85].…”

Enhanced Enzyme Stability Through Site-Directed Covalent Immobilization

“…Stability enhancements have been shown after attachment to many different carriers, examples are magnetic beads (Qiu et al, 2005), mesoporous sol-gel glass (Wang et al, 2001), silica nanospheres (Wang and Caruso, 2004), Sepabeads (Rocchietti et al, 2004), agarose (Rocchietti et al, 2004), and protein-coated microcrystals (Kreiner and Parker, 2005). Many different conjugation chemistries have been used, relying on amine, epoxy, maleic anhydride, glyoxal, biotin/streptavidin, and many other reactive functional groups for enzyme immobilization (Leckband and Langer, 1991;López-Gallego et al, 2013;Maeda et al, 2008;Mateo et al, 2007a;Mazi et al, 2006;Tasso et al, 2009;Zhang et al, 2011). The chemical interactions used for surface attachment/adsorption may primarily be divided into three categories: Van der Waals-based adsorption, ionic adsorption, and covalent attachment (Sheldon, 2007).…”

Preparation of a Cellulose-based Enzyme Membrane Using Ionic Liquid to Lengthen the Duration of Enzyme Stability

“…[6][7][8] Mainly, the methods are divided into 2 categories: covalent bonding and entrapping. While the possibility of loss of the immobilized enzyme exists, through leakage or dissolution, it is small for immobilization achieved by covalent bonding [9][10][11] and cross-linking, [12][13][14][15][16][17][18][19][20] and there remains fear of enzyme activity loss due to reagents used in the bonding reaction; there are means for prolonging the duration of enzyme stability, but the enzyme may be damaged during such immobilization processes.…”