The discovery concerns abnormal proteins at cell level
Scientists at the University of Leeds say they have made a significant discovery which could help in the treatment of "mad cow disease".
The team found a protein which assists in the development of bovine spongiform encephalopathy (BSE) and its human form Creutzfeldt Jakob Disease (CJD).
The protein Glypican-1 was found to cause other proteins in the nervous system to become abnormal.
Professor Nigel Hooper said the find may also help to fight Alzheimer's.
BSE is known to be caused by an abnormal form of prion protein which develop on cells within the nervous system.
However it had previously been unclear why these proteins became abnormal.
Researchers at the Faculty of Biological Sciences in Leeds discovered that the presence of protein Glypican-1 in cells caused the number of abnormal prion proteins to rise.
Professor Hooper explained: "We were looking at how the normal prion protein functions in cells and spotted that it was interacting with something.
"Some lateral thinking and deduction led us to Glypican-1 and when we carried out the experiment, we found we were right.
The scientists found that Glypican-1 acts as a scaffold bringing two forms of the prion protein together which then causes normal prions to mutate into an infectious form.
Professor Hooper said: "Now that we know the identity of one of the key molecules in the disease process, we may in the future be able to design drugs that target this."
He added that it was possible the discovery of the influence of Glypican-1 could have implications for the treatment of other serious diseases.
"While initial experiments haven't shown any link with other neurodegenerative diseases like Alzheimer's , we're not yet completely ruling that out", he said.