19 March 2004. Ozone protects us from solar radiation,
sterilizes, and even cleans our clothes. It’s also a summer
hazard in areas where its levels in surface air rise beyond safe
levels. And here is a new environmental concern to ponder, if
admittedly a far-fetched one at this point: If Jeffrey Kelly and
colleagues are correct, ozone may precipitate formation of the
plaques found in the brains of Alzheimer's patients. Why do
amyloid peptides misfold in some people but not in others? This
question is at the heart of explaining late-onset AD from a
protein misfolding perspective. In this week’s PNAS online,
Kelly, at the Scripps Research Institute, La Jolla, and
colleagues put forth the hypothesis that ozone can convert
relatively inert lipids—cholesterol, in particular—to highly
reactive aldehydes. These aldehydes can then covalently modify
amino acid side chains, turning hydrophilic soluble peptides
into hydrophobic insoluble ones. To find out if this theory
could have any physiological significance, Kelly t