Researchers are using fluorescence lifetime to shed new light on a peptide associated with Alzheimer’s disease.

Through a new approach using time-resolved spectroscopy and computational chemistry, the researchers found experimental evidence of an alternative binding site on amyloid-beta aggregates. The finding opens the door to the development of new therapies for Alzheimer’s and other diseases associated with amyloid deposits.

Amyloid plaque deposits in the brain are a main feature of Alzheimer’s. The Centers for Disease Control and Prevention estimates Alzheimer’s will affect nearly 14 million people in the US by 2060.

“Amyloid-beta is a peptide that aggregates in the brains of people that suffer from Alzheimer’s disease, forming these supramolecular nanoscale fibers, or fibrils” says Angel Martí, a professor of chemistry, bioengineering, and materials science and nanoengineering at Rice University and faculty director of the Rice Emerging Scholars Program. “Once they grow sufficiently, these fibrils precipitate and form what we call amyloid plaques.

“Understanding how molecules in general bind to amyloid-beta is particularly important not only for developing drugs that will bind with better affinity to its aggregates, but also for figuring out who the other players are that contribute to cerebral tissue toxicity,” he adds.

The Martí group had previously identified a first binding site for amyloid-beta deposits by figuring out how metallic dye molecules were able to bind to pockets formed by the fibrils. The molecules’ ability to fluoresce, or emit light when excited under a spectroscope, indicated the presence of the binding site.

Time-resolved spectroscopy, which the lab used in its latest discovery, “is an experimental technique that looks at the time that molecules spend in an excited state,” Martí says. “We excite the molecule with light, the molecule absorbs the energy from the light photons and gets to an excited state, a more energetic state.”

The findings will also affect the study of “many diseases associated with other kinds of amyloids: Parkinson’s, amyotrophic lateral sclerosis (ALS), Type 2 diabetes, systemic amyloidosis,” Marti says.

Understanding the binding mechanisms of amyloid proteins is also useful for studying nonpathogenic amyloids and their potential applications in drug development and materials science.

Read the full article about Alzheimer's research by Silvia Cernea Clark at Futurity.