The Singular Protein Behind Huntington's Disease.

Scientists have discovered the structure of the protein that triggers Huntington's disease, which could lead to a treatment that stops the disease in its tracks. The protein, called huntingtin, develops an abnormally long strand of repeating amino acids within its structure, called the polyglutamine stretch, which builds up in the brain and folds itself into a shape that is toxic to cells. The research team determined the structure of the amyloid nucleus for HTT protein, the "spark" that sets off the chain reaction of protein misfolding, and found that 36 polyQ repeats are the critical number for nucleation to happen in single protein molecules. Armed with this knowledge, the team hopes future work can explore ways of preventing nucleation so that the toxic cascade of protein misfolding is never triggered in the first place.