The rabies virus wreaks havoc on the brain, triggering psychosis and death.
To get where it needs to go, the virus must first trick the nervous system and cross the blood brain barrier -- a process that makes it of interest in drug design.
Parkinson's disease, the slow degeneration of the brain cells that control movement, affects about a million Americans, according to the Parkinson's Foundation, and has no cure.
While the exact cause of Parkinson's disease is unknown, a common feature of the illness is the accumulation of iron in neurons, inflicting damage and cell death.
Some doctors are now using a metal-grabbing compound called deferoxamine to sop up the excess iron in patients, but high doses are needed due to the drug's limited capacity to enter the brain, bringing on serious side effects.
Glycoprotein 29 is a part of the rabies virus that binds to a brain cell receptor and crosses the blood brain barrier.