title: Tyramine-modified pectins via periodate oxidation for soybean hull peroxidase induced hydrogel formation and immobilization.
abstract: Pectin was modified by oxidation with sodium periodate at molar ratios of 2.5, 5, 10, 15 and 20 mol% and reductive amination with tyramine and sodium cyanoborohydride afterwards. Concentration of tyramine groups within modified pectin ranged from 54.5 to 538 μmol/g of dry pectin while concentration of ionizable groups ranged from 3.0 to 4.0 mmol/g of dry polymer compared to 1.5 mmol/g before modification due to the introduction of amino group. All tyramine-pectins showed exceptional gelling properties and could form hydrogel both by cross-linking of carboxyl groups with calcium or by cross-linking phenol groups with peroxidase in the presence of hydrogen peroxide. These hydrogels were tested as carriers for soybean hull peroxidase (SHP) immobilization within microbeads formed in an emulsion based enzymatic polymerization reaction. SHP immobilized within tyramine-pectin microbeads had an increased thermal and organic solvent stability compared to the soluble enzyme. Immobilized SHP was more active in acidic pH region and had slightly decreased Kmvalue of 2.61 mM compared to the soluble enzyme. After 7 cycles of repeated use in batch reactor for pyrogallol oxidation microbeads, immobilized SHP retained half of the initial activity.
authors.affiliation: Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, Belgrade, 11030, Serbia.
authors.forename: Milos
authors.initials: M
authors.lastname: Prokopijevic
authors.affiliation: Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, Belgrade, 11030, Serbia.
authors.forename: Olivera
authors.initials: O
authors.lastname: Prodanovic
authors.affiliation: Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, Belgrade, 11030, Serbia.
authors.forename: Dragica
authors.initials: D
authors.lastname: Spasojevic
authors.affiliation: Department of Biochemistry, Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, 11000, Serbia.
authors.forename: Gordana
authors.initials: G
authors.lastname: Kovacevic
authors.affiliation: Department of Biochemistry, Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, 11000, Serbia.
authors.forename: Natalija
authors.initials: N
authors.lastname: Polovic
authors.affiliation: Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, Belgrade, 11030, Serbia.
authors.forename: Ksenija
authors.initials: K
authors.lastname: Radotic
authors.affiliation: Department of Biochemistry, Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, 11000, Serbia. rprodano@chem.bg.ac.rs.
authors.forename: Radivoje
authors.identifier: http://orcid.org/0000-0003-4662-1825
authors.initials: R
authors.lastname: Prodanovic
mesh_terms: D001894:Borohydrides / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000737:chemistry*; D017743:Equipment Reuse; D020100:Hydrogels / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D010368:Pectins / Q000737:chemistry*; D010504:Periodic Acid / Q000737:chemistry*; D009195:Peroxidase / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry*; D013025:Glycine max / Q000737:chemistry* / Q000201:enzymology; D014439:Tyramine / Q000737:chemistry; D014866:Waste Products
chemical_list: D001894:Borohydrides; D004800:Enzymes, Immobilized; D020100:Hydrogels; D010940:Plant Proteins; D014866:Waste Products; D010504:Periodic Acid; D010368:Pectins; C009288:metaperiodate; D006861:Hydrogen Peroxide; C009282:sodium cyanoborohydride; D009195:Peroxidase; D014439:Tyramine
keywords: Enzyme immobilization; Hydrogels; Pectin modification; Soybean hull peroxidase