Kontakt 2006, 8(2):376-383 | DOI: 10.32725/kont.2006.060

HumaninBiomedicine

Jiřina Slaninová¹, Jiří Patočka²

¹ Ústav organické chemie a biochemie, Akademie věd ČR, Praha

² Jihočeská univerzita v Českých Budějovicích, Zdravotně sociální fakulta, katedra radiologie a toxikologie

The new substance called humanin was discovered by a group of Japanese scientists from Tokyo five years ago. Its discovery was facilitated by isolating a gene that had protective effect in vitro against different factors characteristic for Alzheimer's disease. Humanin is a linear peptide with 24 amino acids with slightly unusual solitary cysteine in position 8. If this cysteine is substituted by alanine, the peptide's activity gets lost; if it is substituted by arginine, the activity is maintained. It is surprising that if we substitute the amino acid in position 14 (serine) for glycine, the activity increases 1000 times. The peptide contains further methionine residue in position 1 and a long hydrophobic chain of leucines (residues 9-12) adjacent to the critical cysteine. The C-end of the peptide is characterized by the presence of a sequence of basic amino acids (Lys-Arg-Arg) in positions 21-23. It was found out that humanin protects cells in some tissues with mutations of certain genes against cell death, including one known as Swedish mutation. In this case, the mutated gene is probably responsible for early form of the familiar Alzheimer's disease. Although the detailed mechanisms of effects of humanin are not known so far, the existing findings give hope to come near to the possibility of medicating Alzheimer's disease. This will require further studies that would confirm the initial promising results and that would lead to modification of the fragile peptide into a more robust form - a new molecule that could become hope in the therapy of Alzheimer's disease.

Keywords: humanin; neuroprotective peptide; Alzheimer's disease; mechanism of effect; structure

Published: December 15, 2006  Show citation