TY - JOUR
T1 - Structural changes in a hydrophobic domain of the prion protein induced by hydration and by Ala → Val and Pro → Leu substitutions
AU - Inouye, Hideyo
AU - Bond, Jeremy
AU - Baldwin, Michael A.
AU - Ball, Haydn L.
AU - Prusiner, Stanley B.
AU - Kirschner, Daniel A.
PY - 2000/7/28
Y1 - 2000/7/28
N2 - X-ray diffraction was used to study the structure of assemblies formed by synthetic peptide fragments of the prion protein (PrP) that include the hydrophobic domain implicated in the Gerstmann-Straussler-Scheinker (GSS) mutation (P102L). The effects of hydration on polypeptide assembly and of Ala → Val substitutions in the hydrophobic domain were characterized. Synthetic peptides included: (i) Syrian hamster (SHa) hydrophobic core, SHa106-122 (KTNMKHMAGAAAAGAVV); (ii) SHa104-122(3A-V), with A → V mutations at 113, 115 and 118 (KPKTNMKHMVGVAAVGAVV); (iii) mouse (Mo) wild-type sequence of the N-terminal hydrophobic domain, Mo89-143WT; and (iv) the same mouse sequence with leucine substitution for proline at residue number 101, Mo89-143(P101L). Samples of SHa106-122 that formed assemblies while drying tinder ambient conditions showed X-ray patterns indicative of 33 Å thick slab-like structures having extensive H-bonding and intersheet stacking. By contrast, lyophilized peptide that was equilibrated against 100% relative humidity showed assemblies with only a few layers of β-sheets. The Ala → Val substitutions in SHa104-122 and Mo89-143(P101L) resulted in the formation of 40 Å wide, cross-β fibrils. Observation of similar size β-sheet fibrils formed by peptides SHa104-122(3A-V) and the longer Mo89-143(P101L) supports the notion that the hydrophobic sequence forms a template or core that promotes the β-folding of the longer peptide. The substitution of amino acids in the mutants, e.g. 3A → V and P101L, enhances the folding of the peptide into compact structural units, significantly enhancing the formation of the extensive β-sheet fibrils. (C) 2000 Academic Press.
AB - X-ray diffraction was used to study the structure of assemblies formed by synthetic peptide fragments of the prion protein (PrP) that include the hydrophobic domain implicated in the Gerstmann-Straussler-Scheinker (GSS) mutation (P102L). The effects of hydration on polypeptide assembly and of Ala → Val substitutions in the hydrophobic domain were characterized. Synthetic peptides included: (i) Syrian hamster (SHa) hydrophobic core, SHa106-122 (KTNMKHMAGAAAAGAVV); (ii) SHa104-122(3A-V), with A → V mutations at 113, 115 and 118 (KPKTNMKHMVGVAAVGAVV); (iii) mouse (Mo) wild-type sequence of the N-terminal hydrophobic domain, Mo89-143WT; and (iv) the same mouse sequence with leucine substitution for proline at residue number 101, Mo89-143(P101L). Samples of SHa106-122 that formed assemblies while drying tinder ambient conditions showed X-ray patterns indicative of 33 Å thick slab-like structures having extensive H-bonding and intersheet stacking. By contrast, lyophilized peptide that was equilibrated against 100% relative humidity showed assemblies with only a few layers of β-sheets. The Ala → Val substitutions in SHa104-122 and Mo89-143(P101L) resulted in the formation of 40 Å wide, cross-β fibrils. Observation of similar size β-sheet fibrils formed by peptides SHa104-122(3A-V) and the longer Mo89-143(P101L) supports the notion that the hydrophobic sequence forms a template or core that promotes the β-folding of the longer peptide. The substitution of amino acids in the mutants, e.g. 3A → V and P101L, enhances the folding of the peptide into compact structural units, significantly enhancing the formation of the extensive β-sheet fibrils. (C) 2000 Academic Press.
KW - Amyloidogenic peptide
KW - Gerstmann-Straussler-Scheinker
KW - Prion
KW - X-ray diffraction
KW - β-pleated sheet
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U2 - 10.1006/jmbi.2000.3926
DO - 10.1006/jmbi.2000.3926
M3 - Article
C2 - 10903869
AN - SCOPUS:0034725542
VL - 300
SP - 1283
EP - 1296
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 5
ER -