21 Dec 2000

A study presented earlier this week at the 2000 International Chemical Congress of Pacific Basin Societies in Honolulu found that by manipulating the structure of amyloid-β, it was possible to reduce the peptide's ability to induce the production of free radicals. The amyloid-β was modified by substituting a sulfur and carbon atom for methionine molecules, which are thought to play a key role in generating free radicals. The modified peptide, when applied to rat brain cells, did not generate free radicals or kills the cells. The study was led by Allan Butterfield, a professor of chemistry and director of the Center for Membrane Sciences at the University of Kentucky in Lexington. In a collaboration with Christopher D. Link, a researcher at the University of Colorado's Institute for Behavioral Genetics, Butterfield's team obtained genetically modified worms that were able to produce either normal human β-amyloid or the modified version. The worms making normal β-amyloid produced free radicals, which damaged the worm muscle proteins. The worms making methionine-substituted amyloid did not produce free radicals, and were subsequently spared damage. The findings provide additional support for the therapeutic value of antioxidants in Alzheimer's, and also suggest that blocking methionine-mediated production of free radicals may offer a novel therapeutic target.—June Kinoshita