A probe invented at Rice University that lights up when it binds to a misfolded amyloid beta peptide, the kind suspected of causing Alzheimer’s disease, has identified a specific binding site on the protein that could facilitate better drugs to treat the disease. Even better, the lab has discovered that when the metallic probe is illuminated, it catalyzes oxidation of the protein in a way they believe might keep it from aggregating in the brains of patients.The study done on long amyloid fibrils backs up computer simulations by colleagues at the University of Miami that predicted the photoluminescent metal complex would attach itself to the amyloid peptide near a hydrophobic (water-avoiding) cleft that appears on the surface of the fibril aggregate. That cleft presents a new target for drugs. Finding the site was relatively simple once the lab used its rhenium-based complexes to target fibrils. The light-switching complex glows when hit with ultraviolet light, but when it binds to the fibril it becomes more than 100 times brighter and causes oxidation of the amyloid peptide.
From Rice University Photo John Vlahakis