NR AWKZ
AU Nilsson,K.P.R.; Sigurdson,C.J.; Aguzzi,A.
TI Conjugated polyelectrolytes - conformation sensitive optical probes for staining and characterization of prion strains
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Poster sessions PR-25
PT Konferenz-Poster
AB It has been suggested that the prion strain phenomenon might be encoded in the conformation of the misfolded protein and that the conformation is the critical mediator of prion susceptibility. Hence, simple, sensitive and versatile tools that can be used to distinguish between different prion strains are of great interest. In previous studies we have shown that conjugated polyelectrolytes (CPs) can be used as conformation sensitive optical probes for the detection of conformational changes in synthetic peptides, amyloid fibril formation in vitro, and for histological staining of amyloid plaques in tissue sections. In contrast to small rigid fluorescent probes, such as thioflavin T (ThT) or Congo red, the conformational flexibility of CP probes allows direct correlation between the geometry of chains and the fluorescence from the probe. If conformational changes of proteins can lead to different conformations of the CP probe, an alteration of the color of the fluorescence from the probe is observed. Hence, CP probes can be used as conformation sensitive optical probes, providing a direct link between spectral signal and protein conformation. In this study, we have utilized fluorescent CPs as dyes for staining of prion deposits in brain tissue sections derived from a transgenic mouse model which overexpresses murine PrP (tga20 mice) to develop murine-adapted strains of BSE, sheep scrapie, and CWD. The technique reported in this article was also verified and compared against conventional staining techniques and biochemical techniques. The binding of the CPs to the three murine passaged ruminant strains was variable and the anionic CP, polythiophene acetic acid (PTAA) showed different spectral signatures when bound to different prion strain deposits, illustrating the ability of CPs being a useful complementary tool to conventional techniques for strain typing of prions. In conclusion, we present a novel technique to distinguish between prion strains in tissue sections.
AD Institute of Neuropathology, Department of Pathology, Universitäts Spital Zürich, Zürich, Switzerland. E-mail: peter.nilsson@usz.ch
SP englisch
PO Italien