INQUIMAE   12526
INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
artículos
Título:
Extracting kinetic parameters for homogeneous [Os(bpy)2ClPyCOOH]+ mediated
Autor/es:
VICTORIA FLEXER; VERONICA IELMINI; ERNESTO JULIO CALVO; P.N. BARTLETT,
Revista:
BIOELECTROCHEMISTRY AND BIOENERGETICS
Editorial:
Elsevier
Referencias:
Lugar: Amsterdam; Año: 2008 vol. 74 p. 201 - 201
ISSN:
0302-4598
Resumen:
The homogeneous reaction between glucose oxidase and osmium bipyridine–pyridine carboxylic acid in the presence of glucose has been studied in detail by cyclic voltammetry and digital simulation. Combination of the analytical equations that describe the dependence of the amperometric response on enzyme, substrate and co-substrate concentrations for the limiting cases with digital simulation of the coupled enzyme reaction diffusion problem allows us to extract kinetic parameters for the substrate–enzyme reaction: KMS=10.8 mM, kcat=254 s−1 and for the redox mediator–enzyme reaction, k=2.2×105 M−1 s−1. The accurate determination of the kinetic parameters at low substrate concentrations (b7 mM) is limited by depletion of the substrate close to the electrode surface. At high substrate concentrations (N20 mM) inactivation of the reduced form of glucose oxidase in the bulk solution must be taken into account in the analysis of the results.–pyridine carboxylic acid in the presence of glucose has been studied in detail by cyclic voltammetry and digital simulation. Combination of the analytical equations that describe the dependence of the amperometric response on enzyme, substrate and co-substrate concentrations for the limiting cases with digital simulation of the coupled enzyme reaction diffusion problem allows us to extract kinetic parameters for the substrate–enzyme reaction: KMS=10.8 mM, kcat=254 s−1 and for the redox mediator–enzyme reaction, k=2.2×105 M−1 s−1. The accurate determination of the kinetic parameters at low substrate concentrations (b7 mM) is limited by depletion of the substrate close to the electrode surface. At high substrate concentrations (N20 mM) inactivation of the reduced form of glucose oxidase in the bulk solution must be taken into account in the analysis of the results.–enzyme reaction: KMS=10.8 mM, kcat=254 s−1 and for the redox mediator–enzyme reaction, k=2.2×105 M−1 s−1. The accurate determination of the kinetic parameters at low substrate concentrations (b7 mM) is limited by depletion of the substrate close to the electrode surface. At high substrate concentrations (N20 mM) inactivation of the reduced form of glucose oxidase in the bulk solution must be taken into account in the analysis of the results.KMS=10.8 mM, kcat=254 s−1 and for the redox mediator–enzyme reaction, k=2.2×105 M−1 s−1. The accurate determination of the kinetic parameters at low substrate concentrations (b7 mM) is limited by depletion of the substrate close to the electrode surface. At high substrate concentrations (N20 mM) inactivation of the reduced form of glucose oxidase in the bulk solution must be taken into account in the analysis of the results.b7 mM) is limited by depletion of the substrate close to the electrode surface. At high substrate concentrations (N20 mM) inactivation of the reduced form of glucose oxidase in the bulk solution must be taken into account in the analysis of the results.N20 mM) inactivation of the reduced form of glucose oxidase in the bulk solution must be taken into account in the analysis of the results.