3-D picture of Alzheimer's peptide created

WALTHAM, Mass., May 13 (UPI) -- U.S. and German scientists say they've created a three-dimensional picture of an Alzheimer's disease peptide using electron microscopy.

Researchers at Brandeis University in Massachusetts and the Leibniz Institute in Jena, Germany, say their achievement is "an important step toward demystifying the role protein clumps play in the development of neurodegenerative disease."

The study marks the first time scientists have shown how A-beta peptides, found in the brains of Alzheimer's patients, form a spaghetti-like protein mass called an amyloid fibril.

"This study is a significant advance regarding our understanding of how fibrils are built from the A-beta peptide," said co-author Nikolaus Grigorieff, a biophysicist at Brandeis University. "People have been guessing for decades what these fibrils look like, but now we have an actual 3D image."

In healthy people A-beta peptide doesn't aggregate, but in Alzheimer's patients it clumps first and then forms long fibrils, like tentacles, said Grigorieff. Scientists disagree whether it's the clumps that kill brain neurons or the fibrils. Grigorieff wants to discover which part of the amyloid structure is toxic -- a step necessary to designing drugs to prevent or treat the disease.

The study appears in the Proceedings of the National Academy of Sciences.