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Solid‐state NMR studies of the prion protein H1 fragment
Author(s) -
Heller Jonathan,
Kolbert Andrew C.,
Larsen Russell,
Ernst Matthias,
Bekker Tatiana,
Baldwin Michael,
Prusiner Stanley B.,
Pines Alexander,
Wemmer David E.
Publication year - 1996
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1002/pro.5560050819
Subject(s) - chemistry , chemical shift , crystallography , magic angle spinning , solid state nuclear magnetic resonance , nuclear magnetic resonance spectroscopy , protein secondary structure , conformational change , helix (gastropod) , protein structure , conformational isomerism , nmr spectra database , stereochemistry , spectral line , nuclear magnetic resonance , molecule , biochemistry , biology , organic chemistry , ecology , physics , snail , astronomy
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 13 C‐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 β‐sheet conformation in the region corresponding to residues 112–121, whereas samples lyophilized from hexa‐fluoroisopropanol display shifts indicative of α‐helical secondary structure in the region corresponding to residues 113–117. Complete conversion to the helical conformation was not observed and conversion from α‐helix back to β‐sheet, as inferred from the solid‐state NMR spectra, occurred when samples were exposed to water. Rotational‐resonance experiments were performed on seven doubly 13 C‐labeled H1 samples dried from water. Measured distances suggest that the peptide is in an extended, possibly β‐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.