Metallic molecules can highlight Alzheimer's roots, when these roots naturally attach to a collection of beta amyloid proteins called fibrils, reveals study.
Fibrils form plaques in the brains of Alzheimer's sufferers, and when the molecules, complexes of dipyridophenazine ruthenium, latch onto amyloid fibrils, their photoluminescence increases 50-fold.
The discovery at Rice University could help researchers design better medications to treat the devastating disease, and also make finding signs of Alzheimer's disease nearly as simple as switching on a light.
Nathan Cook, a former Houston high school teacher and now a Rice graduate student and lead author of the new paper, began studying beta amyloids when he joined Rice bioengineer Angel Marti's lab.
Cook's goal was to find a way to dissolve amyloid fibrils in Alzheimer's patients.
But the research led him down a different path when he realized the ruthenium complexes, the subject of much study in Marti's group, had a distinctive ability to luminesce when combined in a solution with amyloid fibrils.
Ruthenium-based molecules added to the amyloid monomers do not fluoresce, Cook said.
But once the amyloids begin to aggregate into fibrils that resemble "microscopic strands of spaghetti," hydrophobic parts of the metal complex are naturally drawn to them.
"The microenvironment around the aggregated peptide changes and flips the switch that allows the metallic complexes to light up when excited by a spectroscope," he said.
The findings have been reported in the Journal of the American Chemical Society.