THREE years after Stanley Prusiner won a Nobel prize for his prion theory,
researchers in California have finally done the crucial experiment that shows he
was right.
It was Prusiner, a biochemist at the University of California, San Francisco
(UCSF), who suggested that the infectious agents behind BSE and related diseases
were completely different from anything discovered before. Instead of viruses or
bacteria being to blame, he said, a protein twisted into an abnormal shape was
triggering the same shape change in its healthy counterpart. In this way, the
abnormal protein, or prion, could “replicate” and the disease spread.
But …