Steric zipper of the amyloid fibrils formed by residues 109-122 of the Syrian hamster prion protein.
We report the results of atomic force microscopy, Fourier-transform infrared spectroscopy, solid-state nuclear magnetic resonance, and molecular dynamics (MD) calculations for amyloid fibrils formed by residues 109-122 of the Syrian hamster prion protein (H1). Our data reveal that H1 fibrils contain no more than two beta-sheet layers. The peptide strands of H1 fibrils are antiparallel with the A117 residues aligned to form a linear chain in the direction of the fibril axis. The molecular structure of the H1 fibrils, which adopts the motif of steric zipper, is highly uniform in the region of the palindrome sequence AGAAAAGA. The closest distance between the two adjacent beta-sheet layers is found to be about 5 A. The structural features of the molecular model of H1 fibrils obtained by MD simulations are consistent with the experimental results. Overall, our solid-state NMR and MD simulation data indicate that a steric zipper, which was first observed in the crystals of fibril-forming peptides, can be formed in H1 fibrils near the region of the palindrome sequence.
Lee
Shin-Wen
SW
Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 106, Taiwan.
Mou
Yun
Y
Lin
Shu-Yi
SY
Chou
Fang-Chieh
FC
Tseng
Wei-Hsiang
WH
Chen
Chun-hsien
CH
Lu
Chun-Yi David
CY
Yu
Steve S-F
SS
Chan
Jerry C C
JC
D000595:Amino Acid Sequence; D000682:Amyloid / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure; D000818:Animals; D003198:Computer Simulation; D006224:Cricetinae; D008647:Mesocricetus; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010446:Peptide Fragments / Q000737:chemistry* / Q000235:genetics; D011328:Prions / Q000737:chemistry* / Q000235:genetics; D017433:Protein Structure, Secondary; D017550:Spectroscopy, Fourier Transform Infrared
D000682:Amyloid; D010446:Peptide Fragments; D011328:Prions