Structural model of the amyloid fibril formed by β₂- microglobulin #21-31 fragment based on vibrational spectroscopy

A structural model of amyloid fibril formed by the #21-31 fragment of β₂-microglobulin is proposed from microscope IR measurements on specifically ¹³C-labeled peptide fibrils and Raman spectra of the dispersed fibril solution. The ¹³C-shifted amide frequency indicated the secondary structure of the labeled residues. The IR spectra have demonstrated that the region between F22 and V27 forms the core part with the extended β-sheet structure. Raman spectra indicated the formation of a dimer with a disulfide bridge between C25 residues.