Chitosan‐grafted poly(hydroxyethyl methacrylate‐co‐glycidyl methacrylate) membranes for reversible enzyme immobilization

Abstract

Epoxy group‐containing poly(hydroxyethyl methacrylate/glycidyl methacrylate), p(HEMA/GMA), membrane was prepared by UV initiated photopolymerization. The membrane was grafted with chitosan (CH) and some of them were chelated with Fe(III) ions. The CH grafted, p(HEMA/GMA), and Fe(III) ions incorporated p(HEMA/GMA)‐CH‐Fe(III) membranes were used for glucose oxidase (GOD) immobilization via adsorption. The maximum enzyme immobilization capacity of the p(HEMA/GMA)‐CH and p(HEMA/GMA)‐CH‐Fe(III) membranes were 0.89 and 1.36 mg/mL, respectively. The optimal pH value for the immobilized GOD preparations is found to have shifted 0.5 units to more acidic pH 5.0. Optimum temperature for both immobilized preparations was 10°C higher than that of the free enzyme and was significantly broader at higher temperatures. The apparent Km values were found to be 6.9 and 5.8 mM for the adsorbed GOD on p(HEMA/GMA)‐CH and p(HEMA/GMA)‐CH‐Fe(III) membranes, respectively. In addition, all the membranes surfaces were characterized by contact angle measurements. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3084–3093, 2007

An Enzyme Net Coating the Surface of Nanoparticles: A Simple and Efficient Method for the Immobilization of Phospholipase D

“…The pH dependence of transphosphatidylation for free and immobilized PLD at a pH range between 4.0 and 8.0 was also investigated. As illustrated in Figure b, it was seen that a more alkaline pH was more suitable for the immobilized PLD owing to the properties of the surface of the nanoscale silica dioxide. − The initial reaction rate using immobilized PLD of the above free PLD was achieved for all tests. The operational pH values of the immobilized PLD (initial reaction rates of immobilized PLD ≥ the maximum initial reaction rate of free PLD) ranged from 5.0 to 7.0.…”

Synthesis, characterization, and film properties of crosslinked chitosan with pentaerythritol tris[3‐(1‐aziridinyl) propionate]

“…The commercial or practical use of chitin and chitosan (including monomer and oligomers) has been confined to the unmodified forms. As a breakthrough in utilization, chemical modification to chitosan will be a key step 5–8…”