Core structure of amyloid fibril proposed from IR-microscope linear dichroism.
A new approach for studying a peptide conformation of amyloid fibril has been developed. It is based on infrared linear dichroism analysis using an IR-microscope for aligned amyloid fibril. The polarization directions of amide I and II bands were perpendicular similarly for beta2-microglobulin and its #21-31 peptide. Furthermore, this approach has shown that the #21-31 peptide consists of two C=O bonds in the beta-sheet that makes 0 degrees with the fibril axis, three C=O bonds in the beta-sheet inclined by 27 degrees with respect to the fibril axis, four residues in the random coil by 47 degrees , and two residues in possible beta-bulge structure by 32 degrees . Plausible structures of the amyloid core in the fibril are proposed by taking account of these results.
Hiramatsu
Hirotsugu
H
Center for Integrative Bioscience, Okazaki National Research Institutes, Myodaiji, Okazaki 444-8585, Japan.
Goto
Yuji
Y
Naiki
Hironobu
H
Kitagawa
Teizo
T
D016229:Amyloid beta-Peptides / Q000737:chemistry*; D008958:Models, Molecular; D017433:Protein Structure, Secondary; D013055:Spectrophotometry, Infrared / Q000379:methods; D001613:beta 2-Microglobulin / Q000737:chemistry*
D016229:Amyloid beta-Peptides; D001613:beta 2-Microglobulin