title: Binary immobilization of tyrosinase by using alginate gel beads and poly(acrylamide-co-acrylic acid) hydrogels.
abstract: The use of the immobilized and the stable enzymes has immense potential in the enzymatic analysis of clinical, industrial and environmental samples. However, their widespread uses are limited due to the high cost of their production. In this study, binary immobilization of tyrosinase by using Ca-alginate and poly(acrylamide-co-acrylic acid) [P(AAm-co-AA)] was investigated. Maximum reaction rate (Vmax) and Michaelis-Menten constant (Km) were determined for the free and binary immobilized enzymes. The effects of pH, temperature, storage stability, reuse number and thermal stability on the free and immobilized tyrosinase were also examined. For the free and binary immobilized enzymes on Ca-alginate and P(AAm-co-AA), optimum pH was found to be 7 and 5, respectively. Optimum temperature of the free and immobilized enzymes was observed to be 30 and 35 degrees C, respectively. Reuse number, storage and thermal stability of the free tyrosinase were increased by a result of binary immobilization.
authors.affiliation: Department of Chemistry, Faculty of Art and Science, Gazi University, Teknikokullar, 06500 Ankara, Turkey.
authors.forename: Ayşe
authors.initials: A
authors.lastname: Yahşi
authors.forename: Ferat
authors.initials: F
authors.lastname: Sahin
authors.forename: Gökhan
authors.initials: G
authors.lastname: Demirel
authors.forename: Hayrettin
authors.initials: H
authors.lastname: Tümtürk
mesh_terms: D000363:Agaricales / Q000201:enzymology; D000464:Alginates / Q000737:chemistry*; D001205:Ascorbic Acid / Q000737:chemistry; D002118:Calcium / Q000737:chemistry; D002627:Chemistry, Physical / Q000379:methods*; D002686:Chitin / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry; D004795:Enzyme Stability; D004800:Enzymes, Immobilized; D005782:Gels; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006358:Hot Temperature; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D046911:Macromolecular Substances / Q000737:chemistry*; D008863:Microspheres; D014442:Monophenol Monooxygenase / Q000737:chemistry*; D013696:Temperature
chemical_list: D000464:Alginates; D004800:Enzymes, Immobilized; D005782:Gels; D006603:Hexuronic Acids; D020100:Hydrogels; D046911:Macromolecular Substances; D002686:Chitin; D020723:Glucuronic Acid; D048271:Chitosan; D014442:Monophenol Monooxygenase; D001205:Ascorbic Acid; D002118:Calcium