TY  - JOUR
A1  - Badalyan, Artavazd
A1  - Neumann-Schaal, Meina
A1  - Leimkühler, Silke
A1  - Wollenberger, Ursula
T1  - A Biosensor for aromatic aldehydes comprising the mediator dependent PaoABC-Aldehyde oxidoreductase
JF  - Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis
N2  - A novel aldehyde oxidoreductase (PaoABC) from Escherichia coli was utilized for the development of an oxygen insensitive biosensor for benzaldehyde. The enzyme was immobilized in polyvinyl alcohol and currents were measured for aldehyde oxidation with different one and two electron mediators with the highest sensitivity for benzaldehyde in the presence of hexacyanoferrate(III). The benzaldehyde biosensor was optimized with respect to mediator concentration, enzyme loading and pH using potassium hexacyanoferrate(III). The linear measuring range is between 0.5200 mu M benzaldehyde. In correspondence with the substrate selectivity of the enzyme in solution the biosensor revealed a preference for aromatic aldehydes and less effective conversion of aliphatic aldehydes. The biosensor is oxygen independent, which is a particularly attractive feature for application. The biosensor can be applied to detect contaminations with benzaldehyde in solvents such as benzyl alcohol, where traces of benzaldehyde in benzyl alcohol down to 0.0042?% can be detected.
KW  - Aldehyde oxidoreductase
KW  - Benzaldehyde
KW  - Biosensor
KW  - Aromatic aldehydes
KW  - Molybdenum cofactor
Y1  - 2013
U6  - https://doi.org/10.1002/elan.201200362
SN  - 1040-0397
VL  - 25
IS  - 1
SP  - 101
EP  - 108
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Badalyan, Artavazd
A1  - Yoga, Etienne Galemou
A1  - Schwuchow, Viola
A1  - Pöller, Sascha
A1  - Schuhmann, Wolfgang
A1  - Leimkühler, Silke
A1  - Wollenberger, Ursula
T1  - Analysis of the interaction of the molybdenum hydroxylase PaoABC from Escherichia coli with positively and negatively charged metal complexes
JF  - Electrochemistry communications : an international journal dedicated to rapid publications in electrochemistry
N2  - An unusual behavior of the periplasmic aldehyde oxidoreductase (PaoABC) from Escherichia coil has been observed from electrochemical investigations of the enzyme catalyzed oxidation of aromatic aldehydes with different mediators under different conditions of ionic strength. The enzyme has similarity to other molybdoenzymes of the xanthine oxidase family, but the catalytic behavior turned out to be very different. Under steady state conditions the turnover of PaoABC is maximal at pH 4 for the negatively charged ferricyanide and at pH 9 for a positively charged osmium complex. Stopped-flow kinetic measurements of the catalytic half reaction showed that oxidation of benzaldehyde proceeds also above pH 7. Thus, benzaldehyde oxidation can proceed under acidic and basic conditions using this enzyme, a property which has not been described before for molybdenum hydroxylases. It is also suggested that the electron transfer with artificial electron acceptors and PaoABC can proceed at different protein sites and depends on the nature of the electron acceptor in addition to the ionic strength. (C) 2013 Elsevier B.V. All rights reserved.
KW  - Electron transfer
KW  - Multi-cofactor enzymes
KW  - Molybdoenzymes
KW  - Aldehyde oxidoreductase
Y1  - 2013
U6  - https://doi.org/10.1016/j.elecom.2013.09.017
SN  - 1388-2481
SN  - 1873-1902
VL  - 37
SP  - 5
EP  - 7
PB  - Elsevier
CY  - New York
ER  -