1y32

Publication Abstract from PubMed

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.

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 Biochem Biophys Res Commun. 2005 Apr 1;329(1):152-60. PMID:15721287^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.