Dehydrogenase pyrroloquinoline quinone glucose

Yoshida, H., Kojima, K., Witarto, A. B., and Sode, K. (1999). Engineering a chimeric pyrroloquinoline quinone glucose dehydrogenase improvement of EDTA tolerance, thermal stability and substrate specificity. Protein Eng., 12, 63-70. 

Yoshida H, Iguchi T, Sode K (2000) Construction of multi-chimeric pyrroloquinoline quinone glucose dehydrogenase with improved enzymatic properties and application in glucose monitoring. Biotechnol Lett 22(18) 1505-1510... 

Hamamatsu N, Suzumura A, Nomiya Y, Sato M, Aita T, Nakajima M, Husimi Y, Shibanaka Y (2006) Modified substrate specificity of pyrroloquinoline quinone glucose dehydrogenase... 

Zayats M, Katz E, Baron R, Willner I. 2005. Reconstitution of apo-glucose dehydrogenase on pyrroloquinoline quinone-functionalized Au nanoparticles yields an electrically contacted hiocatalyst. J Am Chem Soc 127 12400-12406. 

M. Niculescu, R. Mieliauskiene, V. Laurinavicius and E. Csoregi, Simultaneous detection of ethanol, glucose and glycerol in wines using pyrroloquinoline quinone-dependent dehydrogenases based biosensors, Food Chem., 82(3) (2003) 481 89. 

An alternative biosensor system has been developed by Hart et al. [44] which involves the use of the NAD+-dependent GDH enzyme. The first step of the reaction scheme involves the enzymatic reduction of NAD+ to NADH, which is bought about by the action of GDH on glucose. The analytical signal arises from the electrocatalytic oxidation of NADH back to NAD+ in the presence of the electrocatalyst Meldola s Blue (MB), at a potential of only 0Y. Biosensors utilising this mediator have been reviewed elsewhere [1,17]. Razumiene et al. [45] employed a similar system using both GDH and alcohol dehydrogenase with the cofactor pyrroloquinoline quinone (PQQ), the oxidation of which was mediated by a ferrocene derivative. 

Modified electrodes for this analytical purpose have mostly been formed by electrode adsorption of the mediator systems on the electrode surface or by electropolymerization [24,116]. Recently, for example, NAD(P)H oxidations have been performed on platinum or gold electrodes modified with a monolayer of pyrroloquinoline quinone (PQQ) [117] or on poly(methylene blue)-modified electrodes with different dehydrogenases entrapped in a Nafion film for the amperometric detection of glucose, lactate, malate, or ethanol [118]. In another approach, carbon paste electrodes doped with methylene green or meldola blue together with diaphorase were used for the NADH oxidation [119]. A poly(3-methylthio-phene) conducting polymer electrode was efficient for the oxidation of NADH [120]. By electropolymerization of poly(aniline) in the presence of poly(vinylsulfonate) counterions. 

An analogous amplification process for determination of phenols was proposed based on the kinetics of disappearance of /1-NADH reacting with quinone, which is derived from a phenol in a tyrosinase-catalyzed oxidation. LOD was as low as 50 nM in a 10 min assay . Amplification cycles were also achieved by combining a Pt electrode where phenols are oxidized with a polyurethane layer embedding pyrroloquinoline quinone-dependent glucose dehydrogenase, to catalyze the reduction of the oxidation products . 

The other less common type of phenol biosensor involves enzymes like PQQ (pyrroloquinoline quinone)-dependent glucose dehydrogenase (GDH) (9-12) or... 

Zhao, C., Wittstock, G. Scanning electrochemical microscopy for detection of biosensor and biochip surfaces with immobilized pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase as enzyme label. Biosens Bioelectron 2005, 20, 1277-1284. 

Boenitz-Dulat M, Beck D, Kratzsch P, Schmuck R, Vcm DerEltz H (2007) Improved mutants of Acinetobacter calcoaceticus pyrroloquinoline quinone-dependent soluble glucose dehydrogenase and their use for detection of glucose. WO 2007118647A1... 

Boenitz-Dulat M (2009) Mutants of pyrroloquinoline quinone dependent soluble glucose dehydrogenase. US 20090148874A1... 

Boenitz-Dulat M, Kratzsch P, Schmuck R (2010) Thermostabile mutants of pyrroloquinoline quinone dependent glucose dehydrogenase. US 7,781,196... 

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