A Hexamer of a Peptide Derived from A beta 16-36.
Kreutzer, A.G., Spencer, R.K., McKnelly, K.J., Yoo, S., Hamza, I.L., Salveson, P.J., Nowick, J.S.(2017) Biochemistry 56: 6061-6071
- PubMed: 29028351 
- DOI: https://doi.org/10.1021/acs.biochem.7b00831
- Primary Citation of Related Structures:  
5W4H, 5W4I, 5W4J - PubMed Abstract: 
The absence of high-resolution structures of amyloid oligomers constitutes a major gap in our understanding of amyloid diseases. A growing body of evidence indicates that oligomers of the β-amyloid peptide Aβ are especially important in the progression of Alzheimer's disease. In many Aβ oligomers, the Aβ monomer components are thought to adopt a β-hairpin conformation. This paper describes the design and study of a macrocyclic β-hairpin peptide derived from Aβ 16-36 . Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and size exclusion chromatography studies show that the Aβ 16-36 β-hairpin peptide assembles in solution to form hexamers, trimers, and dimers. X-ray crystallography reveals that the peptide assembles to form a hexamer in the crystal state and that the hexamer is composed of dimers and trimers. Lactate dehydrogenase release assays show that the oligomers formed by the Aβ 16-36 β-hairpin peptide are toxic toward neuronally derived SH-SY5Y cells. Replica-exchange molecular dynamics demonstrates that the hexamer can accommodate full-length Aβ. These findings expand our understanding of the structure, solution-phase behavior, and biological activity of Aβ oligomers and may offer insights into the molecular basis of Alzheimer's disease.
Organizational Affiliation: 
Department of Chemistry, University of California, Irvine , Irvine, California 92697-2025, United States.