title: Complex Media and Enzymatic Kinetics.
abstract: Enzymatic reactions in complex environments often take place with concentrations of enzyme comparable to that of substrate molecules. Two such cases occur when an enzyme is used to detect low concentrations of substrate/analyte or inside a living cell. Such concentrations do not agree with standard in vitro conditions, aimed at satisfying one of the founding hypotheses of the Michaelis-Menten reaction scheme, MM. It would be desirable to generalize the classical approach and show its applicability to complex systems. A permeable micrometrically structured hydrogel matrix was fabricated by protein cross-linking. Glucose oxidase enzyme (GOx) was embedded in the matrix and used as a prototypical system. The concentration of H2O2 was monitored in time and fitted by an accurate solution of the enzymatic kinetic scheme, which is expressed in terms of simple functions. The approach can also find applications in digital microfluidics and in systems biology where the kinetics response in the linear regimes often employed must be replaced.
authors.affiliation: Dipartimento di Chimica "G. Ciamician", Università di Bologna , V. F. Selmi 2, 40126, Bologna, Italy.
authors.forename: Evangelos
authors.initials: E
authors.lastname: Bakalis
authors.affiliation: Dipartimento di Chimica "G. Ciamician", Università di Bologna , V. F. Selmi 2, 40126, Bologna, Italy.
authors.forename: Alice
authors.initials: A
authors.lastname: Soldà
authors.affiliation: Department of Chemistry, University of Ioannina , 45110 Ioannina, Greece.
authors.forename: Marios
authors.initials: M
authors.lastname: Kosmas
authors.affiliation: Dipartimento di Chimica "G. Ciamician", Università di Bologna , V. F. Selmi 2, 40126, Bologna, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Rapino
authors.affiliation: Dipartimento di Chimica "G. Ciamician", Università di Bologna , V. F. Selmi 2, 40126, Bologna, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Zerbetto
mesh_terms: D004566:Electrodes; D005949:Glucose Oxidase / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000032:analysis / Q000378:metabolism; D007700:Kinetics; D013379:Substrate Specificity
chemical_list: D006861:Hydrogen Peroxide; D005949:Glucose Oxidase