Solution structure of humanin, a peptide against Alzheimer's disease-related neurotoxicity.
Benaki, D., Zikos, C., Evangelou, A., Livaniou, E., Vlassi, M., Mikros, E., Pelecanou, M.(2005) Biochem Biophys Res Commun 329: 152-160
- PubMed: 15721287
- DOI: https://doi.org/10.1016/j.bbrc.2005.01.100
- Primary Citation of Related Structures:
1Y32 - PubMed Abstract:
Humanin is a newly identified 24-residue peptide that suppresses neuronal cell death caused by a wide spectrum of familial Alzheimer's disease genes and the beta-amyloid peptide. In this study, NMR and circular dichroism studies of synthetic humanin in aqueous and 30% 2,2,2-trifluoroethanol (TFE) solutions are reported. In aqueous solution, humanin exists predominantly in an unstructured conformation in equilibrium with turn-like structures involving residues Gly5 to Leu10 and Glu15 to Leu18, providing indication of nascent helix. In the less polar environment of 30% TFE, humanin readily adopts helical structure with long-range order spanning residues Gly5 to Leu18. Comparative 3D modeling studies and topology predictions are in qualitative agreement with the experimental findings in both environments. Our studies reveal a flexible peptide in aqueous environment, which is free to interact with possible receptors that mediate its action, but may also acquire a helical conformation necessary for specific interactions and/or passage through membranes.
Organizational Affiliation:
Institute of Biology, NCSR Demokritos, 153 10 Athens, Greece.