Conformational detection of prion protein with biarsenical labeling and FlAsH fluorescence Academic Article uri icon

abstract

  • Prion diseases are associated with the misfolding of the host-encoded cellular prion protein (PrP(C)) into a disease associated form (PrP(Sc)). Recombinant PrP can be refolded into either an alpha-helical rich conformation (alpha-PrP) resembling PrP(C) or a beta-sheet rich, protease resistant form similar to PrP(Sc). Here, we generated tetracysteine tagged recombinant PrP, folded this into alpha- or beta-PrP and determined the levels of FlAsH fluorescence. Insertion of the tetracysteine tag at three different sites within the 91-111 epitope readily distinguished beta-PrP from alpha-PrP upon FlAsH labeling. Labelling of tetracysteine tagged PrP in the alpha-helical form showed minimal fluorescence, whereas labeling of tagged PrP in the beta-sheet form showed high fluorescence indicating that this region is exposed upon conversion. This highlights a region of PrP that can be implicated in the development of diagnostics and is a novel, protease free mechanism for distinguishing PrP(Sc) from PrP(C). This technique may also be applied to any protein that undergoes conformational change and/or misfolding such as those involved in other neurodegenerative disorders including Alzheimer's, Huntington's and Parkinson's diseases.

authors

  • Coleman, Bradley M
  • Nisbet, Rebecca M
  • Han, Sen
  • Cappai, Roberto
  • Hatters, Danny M
  • Hill, Andrew F

publication date

  • March 2009