A new weapon has been discovered in the fight against Parkinson's disease after scientists worked out a way to get rid of toxic clumps of protein in the brain.
The clumps, called Lewy bodies, build up to damage nerve cells and cause cell death, triggering the crippling disease.
The body can't get rid of the Lewy bodies naturally because they aren't properly flagged up for destruction, and medics don't know how to stop them forming.
But researchers have now found the molecule which stops them being condemned and, by blocking it, they can make sure they are removed and don't build up again.
Scientists at Georgetown University Medical Center in Washington DC say the molecule, called USP13, has never been linked to Parkinson's disease before.
'This study provides evidence that USP13 affects development and clearance of Lewy body protein clumps,' said lead investigator Xiaoguang Liu.
Dr Liu added the molecule 'may be a therapeutic target in Parkinson's disease and other similar forms of neurodegeneration.'
Lewy bodies are also linked to a type of dementia and a condition called multiple system atrophy, which causes muscle control problems all over the body
Parkinson's disease is a slowly-progressing condition which damages the brain over time and causes people to shake uncontrollably and lose the ability to move.
Around one in 500 people are thought to be affected by the incurable disease – an estimated 127,00 people in the UK have it.
The Georgetown scientists' research could provide a ray of hope for these people if the proteins causing nerve damage can be stopped.
Although it is unlikely damage could be undone, blocking the build-up of Lewy bodies could stop the condition progressing further.
The research was published in the journal Human Molecular Genetics.