Orientation of tyrosine side chain in neurotoxic Aβ differs in two different secondary structures of the peptide.

ABSTRACT: Amyloid β (Aβ) peptide is present as a major component in amyloid plaque that is one of the hallmarks of Alzheimer's disease. The peptide contains a single tyrosine residue and Aβ has a major implication in the pathology of the disease progression. Current investigation revealed that the tyrosine side chain attained two different critical stereo orientations in two dissimilar conformational states of the peptide. The extended α-helical structure of the peptide observed in an apolar solvent or methanol/water mixture became disordered in aqueous medium and the radius of gyration decreased. In aqueous medium, the torsional angle around C_α-C_β of tyrosine group became -60°. However, in its α-helical conformation in an apolar system, the measured angle was 180° and this rot

SUBMITTER: Das S 

PROVIDER: S-EPMC5098961 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature