杏吧原创

IN ITS healthy form, the protein notorious for its role in mad cow disease
may mop up chemical waste inside cells.

PrP is the brain protein that twists into a pathological shape in BSE and its
human equivalent CJD. The protein鈥檚 healthy form has been shown to stop nerve cells dying
(New 杏吧原创, 17 July, p 13), but it wasn鈥檛 clear how it
might do this.

Now David Brown at the University of Cambridge and his colleagues have shown
that normal PrP can function as a superoxide dismutase, an enzyme that destroys
oxygen radicals. These are by-products of metabolism that can damage or even
kill cells (Biochemical Journal, vol 344, p 1). 鈥淭he disease might be
caused by a loss or change of that function,鈥� says Brown.