July 2, 2009

Potential Alzheimer’s drug target found

A U.S.-led international team of scientists said it has found laboratory evidence that a cluster of peptides might be the toxic agent in Alzheimer's disease.

We believe that we have put a face, a structure, on the molecular assembly that is responsible for Alzheimer's disease, said University of California-Santa Barbara Professor Michael Bowers, who led the study.

The researchers focused on toxic Amyloid Beta 42 peptides, showing how they aggregate.

The AB42 peptide is composed of 42 amino acid residues, the scientists said. A second peptide, AB40, is 10 times more abundant than AB42 in healthy human brains, except it is missing the last two amino acids.

AB40 never grows beyond a certain point and it is non-toxic. But the scientists said AB42 grows to form a structure called a toxic dodecamer that might eventually lead to the large plaques found in the brains of those with Alzheimer's disease and other neurodegenerative diseases.

We are searching for drug candidates that can prevent AB42 from aggregating to form the toxic dodecamer, said Bowers. These latest results are a very hopeful thing. I'm more hopeful now than I have ever been that we can make some real progress on this terrible disease.

The study appears in the journal Nature Chemistry.