@article{Wegerich2005,
  author    = {Wegerich, Franziska},
  title     = {Detektion von Peroxid- und Superoxidf{\"a}ngern mit Hilfe von Proteinsensorchips},
  year      = {2005},
  language  = {de}
}
@article{WegerichTuranoAllegrozzietal.2009,
  author    = {Wegerich, Franziska and Turano, Paola and Allegrozzi, Marco and Moehwald, Helmuth and Lisdat, Fred},
  title     = {Cytochrome c mutants for superoxide biosensors},
  issn      = {0003-2700},
  doi       = {10.1021/Ac802571h},
  year      = {2009},
  abstract  = {The effect of introducing positive charges (lysines) in human cytochrome c (cyt c) on the redox properties and reaction rates of cyt c with superoxide radicals was studied. The mutated forms of this electron-transfer protein are used as sensorial recognition elements for the amperometric detection of the reactive oxygen radical. The proteins were prepared by site-directed mutagenesis focusing on amino acids near the heme edge. The 11 mutants of human cyt c expressed in the course of this research have been characterized by UV-vis spectroscopy, circular dichroism, and NMR spectroscopy to verify overall structure integrity as well as axial coordination of the heme iron. The mutants are investigated voltammetrically using promoter-modified gold electrodes with respect to redox activity and formal redox potential. The rate constants for the reaction with superoxide have been determined spectrophotometrically. Four mutants show a higher reaction rate with the radical as compared to the wild type. These mutants are used for the construction of superoxide sensors based on thiol-modified gold electrodes and covalently fixed proteins. We found that the E66K mutant-based electrode has a clearly higher sensitivity in comparison with the wild-type-based sensor while retaining the high selectivity and showing a good storage stability.},
  language  = {en}
}
@phdthesis{Wegerich2010,
  author    = {Wegerich, Franziska},
  title     = {Engineered human cytochrome c : investigation of superoxide and protein-protein interaction and application in bioelectronic systems},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-50782},
  school      = {Universit{\"a}t Potsdam},
  year      = {2010},
  abstract  = {The aim of this thesis is the design, expression and purification of human cytochrome c mutants and their characterization with regard to electrochemical and structural properties as well as with respect to the reaction with the superoxide radical and the selected proteins sulfite oxidase from human and fungi bilirubin oxidase. All three interaction partners are studied here for the first time with human cyt c and with mutant forms of cyt c. A further aim is the incorporation of the different cyt c forms in two bioelectronic systems: an electrochemical superoxide biosensor with an enhanced sensitivity and a protein multilayer assembly with and without bilirubin oxidase on electrodes. The first part of the thesis is dedicated to the design, expression and characterization of the mutants. A focus is here the electrochemical characterization of the protein in solution and immobilized on electrodes. Further the reaction of these mutants with superoxide was investigated and the possible reaction mechanisms are discussed. In the second part of the work an amperometric superoxide biosensor with selected human cytochrome c mutants was constructed and the performance of the sensor electrodes was studied. The human wild-type and four of the five mutant electrodes could be applied successfully for the detection of the superoxide radical. In the third part of the thesis the reaction of horse heart cyt c, the human wild-type and seven human cyt c mutants with the two proteins sulfite oxidase and bilirubin oxidase was studied electrochemically and the influence of the mutations on the electron transfer reactions was discussed. Finally protein multilayer electrodes with different cyt form including the mutant forms G77K and N70K which exhibit different reaction rates towards BOD were investigated and BOD together with the wild-type and engineered cyt c was embedded in the multilayer assembly. The relevant electron transfer steps and the kinetic behavior of the multilayer electrodes are investigated since the functionality of electroactive multilayer assemblies with incorporated redox proteins is often limited by the electron transfer abilities of the proteins within the multilayer. The formation via the layer-by-layer technique and the kinetic behavior of the mono and bi-protein multilayer system are studied by SPR and cyclic voltammetry. In conclusion this thesis shows that protein engineering is a helpful instrument to study protein reactions as well as electron transfer mechanisms of complex bioelectronic systems (such as bi-protein multilayers). Furthermore, the possibility to design tailored recognition elements for the construction of biosensors with an improved performance is demonstrated.},
  language  = {en}
}
@article{KrylovAdamzigWalteretal.2006,
  author    = {Krylov, Andrey. V. and Adamzig, H. and Walter, A. D. and Loechel, B. and Kurth, E. and Pulz, O. and Szeponik, Jan and Wegerich, Franziska and Lisdat, Fred},
  title     = {Parallel generation and detection of superoxide and hydrogen peroxide in a fluidic chip},
  series = {Sensors and actuators : B, Chemical},
  volume    = {119},
  journal   = {Sensors and actuators : B, Chemical},
  number    = {1},
  publisher = {Elsevier},
  address   = {Lausanne},
  issn      = {0925-4005},
  doi       = {10.1016/j.snb.2005.11.062},
  pages     = {118 -- 126},
  year      = {2006},
  abstract  = {A fluidic chip system was developed, which combines a stable generation of superoxide radicals and hydrogen peroxide with their sensorial detection. The generation of both reactive oxygen species was achieved by immobilization of xanthine oxidase on controlled pore glass in a reaction chamber. Antioxidants can be introduced into the fluidic chip system by means of mixing chamber. The detection of both species is based on the amperometric principle using a biosensor chip with two working electrodes. As sensing protein for both electrodes cytochrome c was used. The novel system was designed for the quantification of the antioxidant efficiency of different potential scavengers of the respective reactive species in an aqueous medium. Several model antioxidants such as ascorbic acid or catalase have been tested under flow conditions.},
  language  = {en}
}