NR AFHK
AU Heller,J.; Kolbert,A.C.; Larsen,R.; Ernst,M.; Bekker,T.; Baldwin,M.A.; Prusiner,S.B.; Pines,A.; Wemmer,D.E.
TI Solid-state NMR studies of the prion protein H1 fragment
QU Protein Science 1996 Aug; 5(8): 1655-61
IA http://www.proteinscience.org/cgi/reprint/5/8/1655
PT journal article
AB Conformational changes in the prion protein (PrP) seem to be responsible for prion diseases. We have used conformation-dependent chemical-shift measurements and rotational-resonance distance measurements to analyze the conformation of solid-state peptides lacking long-range order, corresponding to a region of PrP designated H1. This region is predicted to undergo a transformation of secondary structure in generating the infectious form of the protein. Solid-state NMR spectra of specifically 13C-enriched samples of H1, residues 109-122 (MKHMAGAAAAGAVV) of Syrian hamster PrP, have been acquired under cross-polarization and magic-angle spinning conditions. Samples lyophilized from 50% acetonitrile/50% water show chemical shifts characteristic of a beta-sheet conformation in the region corresponding to residues 112-121, whereas samples lyophilized from hexafluoroisopropanol display shifts indicative of alpha-helical secondary structure in the region corresponding to residues 113-117. Complete conversion to the helical conformation was not observed and conversion from alpha-helix back to beta-sheet, as inferred from the solid-state NMR spectra, occurred when samples were exposed to water. Rotational-resonance experiments were performed on seven doubly 13C-labeled H1 samples dried from water. Measured distances suggest that the peptide is in an extended, possibly beta-strand, conformation. These results are consistent with the experimental observation that PrP can exist in different conformational states and with structural predictions based on biological data and theoretical modeling that suggest that H1 may play a key role in the conformational transition involved in the development of prion diseases.
IN Prionproteinpeptide, welche den Aminosäuren 109-122 (MKHMAGAAAAGAVV) des syrischen Hamsters entsprachen, wurden getrocknet und mittels NMR untersucht. Wurden die Peptide aus Wasser oder 50% Acetonitril / 50% Wasser gefiergetrocknet, dann lagen offenbar die Aminosäuren 112-121 in einer ß-Faltblatt-Struktur vor. Wurden die Peptide dagegen aus Hexafluorisopropanol gefiergetrocknet, dann zeigten die Aminosäuren 1132-127 Merkmale einer Alphahelix.
ZR 53
MH Amino Acid Sequence; Animal; Hamsters; Magnetic Resonance Spectroscopy; Mesocricetus; Peptide Fragments/chemical synthesis/*chemistry; Prions/*chemistry; *Protein Structure, Secondary; Support, Non-U.S. Gov't; Support, U.S. Gov't, Non-P.H.S.; Support, U.S. Gov't, P.H.S.
AD Graduate Group in Biophysics, University of California, Berkeley 94720, USA
SP englisch
PO USA
OR Prion-Krankheiten H