@misc{YarmanPengWuetal., author = {Yarman, Aysu and Peng, Lei and Wu, Yunhua and Bandodkar, Amay and Gajovic-Eichelmann, Nenad and Wollenberger, Ulla and Hofrichter, Martin and Ullrich, Ren{\´e} and Scheibner, Katrin and Scheller, Frieder W.}, title = {Can peroxygenase and microperoxidase substitute cytochrome P450 in biosensors}, series = {Bioanalytical Reviews}, volume = {3}, journal = {Bioanalytical Reviews}, number = {2-4}, issn = {1867-2094}, doi = {10.1007/s12566-011-0023-4}, pages = {67 -- 94}, abstract = {Aromatic peroxygenase (APO) from the basidiomycetous mushroom Agrocybe aegerita (AaeAPO) and microperoxidases (MPs) obtained from cytochrome c exhibit a broad substrate spectrum including hydroxylation of selected aromatic substrates, demethylation and epoxidation by means of hydrogen peroxide. It overlaps with that of cytochrome P450 (P450), making MPs and APOs to alternate recognition elements in biosensors for the detection of typical P450 substrates. Here, we discuss recently developed approaches using microperoxidases and peroxygenases in view of their potential to supplement P450 enzymes as recognition elements in biosensors for aromatic compounds. Starting as early as the 1970s, the direct electron transfer between electrodes and the heme group of heme peptides called microperoxidases has been used as a model of oxidoreductases. These MP-modified electrodes are used as hydrogen peroxide detectors based on the catalytic current generated by electrically contacted microperoxidase molecules. A similar catalytic reaction has been obtained for the electrode-immobilised heme protein AaeAPO. However, up to now, no MP-based sensors for substrates have been described. In this review, we present biosensors which indicate 4-nitrophenol, aniline, naphthalene and p-aminophenol based on the peroxide-dependent substrate conversion by electrode-immobilised MP and AaeAPO. In these enzyme electrodes, the signal is generated by the conversion of all substrates, thus representing in complex media an overall parameter. The performance of these sensors and their further development are discussed in comparison with P450-based electrodes.}, language = {en} } @misc{PengWollenbergerKinneetal., author = {Peng, Lei and Wollenberger, Ulla and Kinne, Matthias and Hofrichter, Martin and Ullrich, Ren{\´e} and Scheibner, Katrin and Fischer, Anna and Scheller, Frieder W.}, title = {Peroxygenase based sensor for aromatic compounds}, series = {Biosensors and Bioelectronics}, volume = {26}, journal = {Biosensors and Bioelectronics}, number = {4}, issn = {1873-4235}, doi = {10.1016/j.bios.2010.07.075}, url = {http://nbn-resolving.de/http://www.sciencedirect.com/science/article/pii/S0956566310004501}, pages = {1432 -- 1436}, abstract = {We report on the redox behaviour of the peroxygenase from Agrocybe aegerita (AaeAPO) which has been electrostatically immobilized in a matrix of chitosan-embedded gold nanoparticles on the surface of a glassy carbon electrode. AaeAPO contains a covalently bound heme-thiolate as the redox active group that exchanges directly electrons with the electrode via the gold nanoparticles. The formal potential E ° ′ of AaeAPO in the gold nanoparticles-chitosan film was estimated to be -(286 ± 9) mV at pH 7.0. The heterogeneous electron transfer rate constant (ks) increases from 3.7 in the scan rate range from 0.2 to 3.0 V s-1 and level off at 63.7 s-1. Furthermore, the peroxide-dependent hydroxylation of aromatic compounds was applied to develop a sensor for naphthalene and nitrophenol. The amperometric measurements of naphthalene are based on the indication of H2O2 consumption. For the chitosan-embedded gold nanoparticle system, the linear range extends from 4 to 40 μM naphthalene with a detection limit of 4.0 μM (S/N = 3) and repeatability of 5.7\% for 40 μM naphthalene.}, language = {en} } @misc{PengWollenbergerHofrichteretal., author = {Peng, Lei and Wollenberger, Ulla and Hofrichter, Martin and Ullrich, Ren{\´e} and Scheibner, Katrin and Scheller, Frieder W.}, title = {Bioelectrocatalytic properties of Agrocybe aegerita peroxygenase}, series = {Electrochimica Acta}, volume = {55}, journal = {Electrochimica Acta}, number = {27}, issn = {0013-4686}, doi = {10.1016/j.electacta.2009.12.065}, pages = {7809 -- 7813}, abstract = {A biosensor for detecting the aromatic substance 4-nitrophenol based on Agrocybe aegerita peroxygenase (AaP) immobilized with chitosan-stabilized gold nanoparticles is presented here. This biosensor measures the enzymatic product of 4-nitrophenol peroxygenation, 4-nitrocatechol, which is electrochemically detected in the presence of hydrogen peroxide. Cyclic voltammetry and amperometry were used to characterize the proposed biosensor. The linear range of the AaP biosensor for the detection of 4-nitrophenol was between 10 and 30 μM with a detection limit of 0.2 μM (based on the S/N = 3). The catalytic property of AaP to oxidize 4-nitrophenol was compared with two other heme proteins, a camphor-hydroxylating cytochrome P450 monooxygenase (P450cam, CYP101) and horseradish peroxidase (HRP). The results revealed that only AaP is capable of catalyzing the hydroxylation of 4-nitrophenol into 4-nitrocatechol. Consequently, AaP could be a particularly potent biocatalyst that may fill the gap between cytochrome P450s and common heme peroxidases.}, language = {en} } @misc{YarmanGroebeNeumannetal., author = {Yarman, Aysu and Gr{\"o}be, Glenn and Neumann, Bettina and Kinne, Mathias and Gajovic-Eichelmann, Nenad and Wollenberger, Ulla and Hofrichter, Martin and Ullrich, Ren{\´e} and Scheibner, Katrin and Scheller, Frieder W.}, title = {The aromatic peroxygenase from Marasmius rutola—a new enzyme for biosensor applications}, series = {Analytical and Bioanalytical Chemistry}, volume = {402}, journal = {Analytical and Bioanalytical Chemistry}, number = {1}, issn = {1618-2650}, doi = {10.1007/s00216-011-5497-y}, pages = {405 -- 412}, abstract = {The aromatic peroxygenase (APO; EC 1.11.2.1) from the agraric basidomycete Marasmius rotula (MroAPO) immobilized at the chitosan-capped gold-nanoparticle-modified glassy carbon electrode displayed a pair of redox peaks with a midpoint potential of -278.5 mV vs. AgCl/AgCl (1 M KCl) for the Fe2+/Fe3+ redox couple of the heme-thiolate-containing protein. MroAPO oxidizes aromatic substrates such as aniline, p-aminophenol, hydroquinone, resorcinol, catechol, and paracetamol by means of hydrogen peroxide. The substrate spectrum overlaps with those of cytochrome P450s and plant peroxidases which are relevant in environmental analysis and drug monitoring. In M. rotula peroxygenase-based enzyme electrodes, the signal is generated by the reduction of electrode-active reaction products (e.g., p-benzoquinone and p-quinoneimine) with electro-enzymatic recycling of the analyte. In these enzyme electrodes, the signal reflects the conversion of all substrates thus representing an overall parameter in complex media. The performance of these sensors and their further development are discussed.}, language = {en} }