Identification of a beta-turn in the tertiary structure of a peptide fragment of the Alzheimer amyloid protein.

In an attempt to understand the three-dimensional structure of the Alzheimer amyloid protein, a fragment decapeptide was studied by nuclear magnetic resonance spectroscopy. Using two-dimensional techniques, protons close in space were identified and their interproton distances determined. These distances were then used as input data for distance geometry calculations. The resulting three-dimensional structures suggest the presence of a beta-turn in the C-terminus of the decapeptide.