@article{KlughammerSchreiber2016,
  author    = {Klughammer, Christof and Schreiber, Ulrich},
  title     = {Deconvolution of ferredoxin, plastocyanin, and P700 transmittance changes in intact leaves with a new type of kinetic LED array spectrophotometer},
  series = {Photosynthesis Research},
  volume    = {128},
  journal   = {Photosynthesis Research},
  number    = {2},
  doi       = {10.1007/s11120-016-0219-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-189050},
  pages     = {195-214},
  year      = {2016},
  abstract  = {A newly developed compact measuring system for assessment of transmittance changes in the near-infrared spectral region is described; it allows deconvolution of redox changes due to ferredoxin (Fd), P700, and plastocyanin (PC) in intact leaves. In addition, it can also simultaneously measure chlorophyll fluorescence. The major opto-electronic components as well as the principles of data acquisition and signal deconvolution are outlined. Four original pulse-modulated dual-wavelength difference signals are measured (785-840 nm, 810-870 nm, 870-970 nm, and 795-970 nm). Deconvolution is based on specific spectral information presented graphically in the form of 'Differential Model Plots' (DMP) of Fd, P700, and PC that are derived empirically from selective changes of these three components under appropriately chosen physiological conditions. Whereas information on maximal changes of Fd is obtained upon illumination after dark-acclimation, maximal changes of P700 and PC can be readily induced by saturating light pulses in the presence of far-red light. Using the information of DMP and maximal changes, the new measuring system enables on-line deconvolution of Fd, P700, and PC. The performance of the new device is demonstrated by some examples of practical applications, including fast measurements of flash relaxation kinetics and of the Fd, P700, and PC changes paralleling the polyphasic fluorescence rise upon application of a 300-ms pulse of saturating light.},
  language  = {en}
}
@phdthesis{Pasquet2014,
  author    = {Pasquet, Vivian},
  title     = {Characterization of thioredoxin and glutathione reductase activities of Mesocestoides vogae, a flatworm parasite useful as a laboratory model for the screening of drugs.},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-106759},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2014},
  abstract  = {Flatworm parasites (platyhelminths) cause serious infection diseases in humans, such as schistosomiasis and hydatid disease, mainly prevalent in developing countries. However, the current repertoire of drug armamentarium used to combat flatworm infections is limited. For instance, praziquantel is the only drug available for mass treatment of Schistosoma infections. In contrast to their hosts, flatworm parasites possess a distinct redox arrangement of redox pathways in which the selenoenzyme thioredoxin glutathione reductase (TGR) controls the overall redox homeostasis. Interference with this enzyme leads to parasite death. Hence, this key redox enzyme seems to be a new promising drug target against flatworm infections. Because most flatworms are difficult to cultivate in the laboratory (e.g. Echinococcus granulosus experimental infection in mice takes about 10 month to develop into cysts), this work was focused on Mesocestoides vogae (syn. corti), a non-human flatworm parasite which is an interesting laboratory model to study other flatworm infections: it is very rare in humans, can be easily manipulated both in vivo and in vitro and grows extremely fast in mice. With the aim to assess TGR inhibitors as possible drugs to treat flatworm infections, the thioredoxin and glutathione pathways of M.vogae were studied. Here, the objectives were to study whether the biochemical pathways that maintain the redox homeostasis in M. vogae conform to the general biochemical scenario proposed for other platyhelminth parasites. Here, it was proven that M. vogae extracts possess both thioredoxin and glutathione reductase activities. The thioredoxin and glutathione reductase activities were partially purified from total extracts by a combination of ammonium sulfate precipitation, anion exchange and hydroxyapatite chromatography. Both activities co-purified in all steps which strongly indicates the existence of TGR rather than a single TR and GR. Furthermore partially purified activities could be inhibited by the organogold compound auranofin, a known TGR inhibitor. Moreover, the glutathione reductase activity displays hysteresis (a peculiar kinetic behavior) at high concentrations of oxidised glutathione, a feature typical of flatworm TGRs, but not of conventional GR. Although M. vogae activities could not be purified to homogeneity, the overall results strongly indicate that this flatworm possesses TGR and lacks conventional GR and TR. Furthermore the thiadiazole WPQ75 and the N-oxide VL16E (a furoxan derivate) were identified as inhibitors of TGR activity of M.vogae at a 10 µM concentration. These inhibitors were able to kill M.vogae larval worms in vitro as well as in experimental infection in mice. Due to the existence of TGR activity in M.vogae, the possibility to inhibit this activity with recently discovered inhibitors of flatworm TGR and the successes achieved by testing these inhibitors both in vitro and in vivo, it is strongly evident that M. vogae would be an excellent model to assess TGR inhibitors in flatworm infections.},
  subject      = {Thioredoxin},
  language  = {en}
}