title: Controlling enzymatic activity by immobilization on graphene oxide.
abstract: In this study, graphene oxide (GO) has been applied as a matrix for enzyme immobilization. The protein adsorption capacity of GO is much higher than of other large surface area carbonaceous materials. Its structure and physicochemical properties are reported beneficial also for enzymatic activity modifications. The experimental proof was done here that GO-based biocatalytic systems with immobilized catalase are modifiable in terms of catalyzed reaction kinetic constants. It was found that activity and stability of catalase, considered here as model enzyme, closely depend on enzyme/GO ratio. The changes in kinetic parameters can be related to secondary structure alterations. The correlation between enzyme/GO ratio and kinetic and structure parameters is reported for the first time and enables the conscious control of biocatalytic processes and their extended applications. The biological activity of obtained biocatalytic systems was confirmed in vitro by the use of functional test. The addition of immobilized catalase improved the cells' viability after they were exposed to hydrogen peroxide and tert-butyl-hydroperoxide used as source of reactive oxygen species.
authors.affiliation: Faculty of Chemistry, Physicochemistry of Carbon Materials Research Group, Nicolaus Copernicus University in Toruń, Gagarin St. 7, 87-100, Toruń, Poland.
authors.forename: Paulina
authors.initials: P
authors.lastname: Bolibok
authors.affiliation: Faculty of Chemistry, Physicochemistry of Carbon Materials Research Group, Nicolaus Copernicus University in Toruń, Gagarin St. 7, 87-100, Toruń, Poland. marekw@umk.pl.|INVEST-TECH R&D Center, Plaska St. 32-34, 87-100, Toruń, Poland. marekw@umk.pl.
authors.forename: Marek
authors.initials: M
authors.lastname: Wiśniewski
authors.affiliation: Department of Biochemistry, Faculty of Biology and Environment Protection, Nicolaus Copernicus University in Toruń, Gagarin St. 7, 87-100, Toruń, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Roszek
authors.affiliation: Faculty of Chemistry, Physicochemistry of Carbon Materials Research Group, Nicolaus Copernicus University in Toruń, Gagarin St. 7, 87-100, Toruń, Poland.
authors.forename: Artur P
authors.initials: AP
authors.lastname: Terzyk
mesh_terms: D000818:Animals; D055162:Biocatalysis; D016466:CHO Cells; D002374:Catalase / Q000737:chemistry / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects; D003412:Cricetulus; D004789:Enzyme Activation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D006108:Graphite / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007700:Kinetics; D017433:Protein Structure, Secondary; D020122:tert-Butylhydroperoxide / Q000494:pharmacology
chemical_list: D004800:Enzymes, Immobilized; D006108:Graphite; D020122:tert-Butylhydroperoxide; D006861:Hydrogen Peroxide; D002374:Catalase
keywords: Catalase; Graphene oxide; Immobilization; Kinetic parameters; Secondary structure alterations