Stabilization of Glucose Dehydrogenase with Polyethyleneimine in an Electrochemical Reactor with NAD(P) + Regeneration

Stabilization of Glucose Dehydrogenase with Polyethyleneimine in an Electrochemical Reactor with NAD(P) + Regeneration

The stability of the enzyme glucose dehydrogenase (GDH) has been studied under turnover conditions in an electrochemical reactor with NAD(P) + regeneration on a preparative scale. The enzyme showed first‐order deactivation patterns closely related to imposed potential. An increase in the applied pot...

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Bibliographic Details
Published in:Biotechnology progress Vol. 13; no. 5; pp. 557 - 561
Main Authors: Obón, José María, Casanova, Pastora, Manjón, Arturo, Fernández, Víctor M., Iborra, José Luis
Format: Journal Article
Language:English
Published: USA American Chemical Society 1997
American Institute of Chemical Engineers
Subjects:
Biological and medical sciences
Biotechnology
Enzyme engineering
Fundamental and applied biological sciences. Psychology
Methods. Procedures. Technologies
Miscellaneous
Performance evaluation
Stability
Enzyme
Stabilization
Glucose 1-dehydrogenase
Coenzyme
NAD
Regeneration
Bioreactor
Preparative scale
Enzymatic activity
Electrochemistry
Oxidoreductases
NADP
Polyethylene imine
Enzymatic reaction
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Summary:The stability of the enzyme glucose dehydrogenase (GDH) has been studied under turnover conditions in an electrochemical reactor with NAD(P) + regeneration on a preparative scale. The enzyme showed first‐order deactivation patterns closely related to imposed potential. An increase in the applied potential caused a decrease of the half‐life deactivation time of the enzyme (t1/2) . However, this detrimental effect was compensated with an enhancement of the substrate consumption rate (rs) attained as a consequence of the higher cofactor regeneration rates observed at more positive potentials. A 0.7 V potential (vs Ag|AgCl) was selected as a compromise between the activity and the stability of the enzyme (t1/2 = 4.2 h; rs = 32 μmol min−1) . The protective effect on the activity of glucose dehydrogenase of well‐known stabilizing agents such as NaCl, sorbitol, bovine serum albumin (BSA) or polyethyleneimine (PEI) has been studied. PEI (50 000 MW) at concentrations between 0.3 and 0.5 mM showed the highest protection of the enzyme activity in the electrochemical reactor as well as the highest substrate consumption rates (t1/2 = 24.5 h; rs = 59 μmol min−1) . This beneficial effect of PEI is explained in terms of an electrode, cofactor, and enzyme modification that induces an increase of the concentrations of NAD(P) H and glucose dehydrogenase in the vicinity of the electrode and minimizes the adsorption of the enzyme on the electrode contact.
Bibliography:istex:7DCE17BC18EAD1F98C7913A8A8E3EB86FB8B2719
ark:/67375/WNG-MV6NT0NX-V
ArticleID:BTPR970063
ISSN:8756-7938
1520-6033
DOI:10.1021/bp970063u