Metal-dependent alpha-helix formation promoted by the glycine-rich octapeptide region of prion protein.
Prion diseases share a common feature in that the normal cellular prion protein (PrP(C)) converts to a protease-resistant isoform PrP(Sc). The alpha-helix-rich C-terminal half of PrP(C) is partly converted into beta-sheet in PrP(Sc). We have examined by Raman spectroscopy the structure of an octapeptide PHGGGWGQ that appears in the N-terminal region of PrP(C) and a longer peptide containing the octapeptide region. The peptides do not assume any regular structure without divalent metal ions, whereas Cu(II) binding to the HGGG segment induces formation of alpha-helical structure on the C-terminal side of the peptide chain. The N-terminal octapeptide of prion protein may be a novel structural motif that acts as a promoter of alpha-helix formation.
Pharmaceutical Institute, Tohoku University, Sendai, Japan.
T
T
Miura
A
A
Hori-i
H
H
Takeuchi
D000595:Amino Acid Sequence; D001665:Binding Sites; D003300:Copper / Q000378:metabolism*; D005998:Glycine / Q000032:analysis; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism; D018621:PrPC Proteins / Q000737:chemistry* / Q000378:metabolism; D017433:Protein Structure, Secondary; D013059:Spectrum Analysis, Raman
D010446:Peptide Fragments; D018621:PrPC Proteins; D003300:Copper; D005998:Glycine