Soybean hull peroxidase immobilization on macroporous glycidyl methacrylates with different surface characteristics.
Soybean hull peroxidase (SHP, E.C. 1.11.1.7) was immobilized by a glutaraldehyde and periodate method onto series of macroporous copolymers of glycidyl methacrylate (GMA) and ethylene glycol dimethacrylate (EGDMA), poly(GMA-co-EGDMA) with various surface characteristics and pore size diameters ranging from 44 to 200 nm. Glutaraldehyde immobilization method and poly(GMA-co-EGDMA) named SGE 20/12 with pore sizes of 120 nm gave immobilized enzyme with highest specific activity of 25 U/g. Deactivation studies showed that immobilization increased stability of SHP and that surface characteristics of the used copolymer had a major influence on a stability of immobilized enzyme at high temperatures and in an organic solvent. The highest thermostability was obtained using the copolymer SGE 20/12 with pore size of 120 nm, while the highest stability in dioxane had SHP immobilized onto copolymer SGE 10/4 with pore size of 44 nm. Immobilized SHP showed a wider pH optimum as compared to the native enzyme especially at alkaline pH values and 3.2 times increased K m value for pyrogallol. After 6 cycles of repeated use in batch reactor, immobilized SHP retained 25 % of its original activity. Macroporous copolymers with different surface characteristics can be used for fine tuning of activity and stability of immobilized SHP to obtain a biocatalyst suitable for phenol oxidation or polymer synthesis in organic solvents.
Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11030, Belgrade, Serbia.
Milos
M
Prokopijevic
Olivera
O
Prodanovic
Dragica
D
Spasojevic
Zeljko
Z
Stojanovic
Ksenija
K
Radotic
Radivoje
R
Prodanovic
D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry*; D004852:Epoxy Compounds / Q000737:chemistry*; D006358:Hot Temperature; D008689:Methacrylates / Q000737:chemistry*; D009195:Peroxidase / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry*; D013025:Glycine max / Q000201:enzymology*; D013499:Surface Properties
D004800:Enzymes, Immobilized; D004852:Epoxy Compounds; D008689:Methacrylates; D010940:Plant Proteins; D009195:Peroxidase; C007870:glycidyl methacrylate