NR ATRI
AU Kaimann,T.K.; Metzger,S.; Jansen,K.; Riesner,D.
TI Identification of potential interaction sites in alpha-helical dimers of the prion protein
QU International Conference - Prion 2005: Between fundamentals and society's needs - 19.10.-21.10.2005, Congress Center Düsseldorf - Poster Session: Structure of PrP and molecular determinants of infectivity STRCT-24
PT Konferenz-Poster
AB
Conversion of the cellular isoform of the prion protein, PrPc, into the pathogenic form PrPsc is a fundamental event in the development of prion disease. The underlying mechanism however is still poorly understood and therefore the analysis and identification of intermediate states are of extreme importance. Transitions from a conformation with PrPc-like properties such as solubility and alpha-helical structure to a PrPsc-like conformation with its insolubility and beta-sheet rich structure, can be induced by slight changes of solvent conditions, here low concentrations (< 0.1%) of the anionic detergent sodium dodecyl sulfate (SDS) at room temperature and neutral pH. A non-covalent alpha-helical dimer of recPrP 90-231 was described earlier (1) and displays a potential first step in the conversion process. In the present work, the structural properties of the alpha-helical dimer were analyzed by chemical cross-linking PrP-dimers using zero-length cross-linker EDC. Determination of contact sites within such complexes were carried out by tryptic digestion and identifying the resulting peptides by mass spectrometry. Two peptides were presented in lower concentration after cross-linking and tryptic digestion and altogether three cross-linked peptides could be identified revealing preferential linkage of the N-terminus with the C-terminal part of helix 1 and three acidic residues in helix 2. The results can be interpreted in terms of structural models of dimer interaction.
(1) Jansen et al. (2001) Biological Chemistry, 382, 683-691
AD T.K.Kaimann, K.Jansen, D.Riesner, Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Germany; T.K.Kaimann, S.Metzger, K.Jansen, D.Riesner, Biologisch-Medizinisches Forschungszentrum Düsseldorf, Germany
SP englisch
PO Deutschland