Saturday, January 10, 2009

Yeast engineered to produce rare malaria medicine

Jay Keasling--Saving the World, One Molecule at a Time
By Jeneen Interlandi
Dec 20, 2008

Ever since Alexander Fleming noticed a clump of blue-green mold destroying a neighboring culture of bacteria in a nearly discarded petri dish, scientists have searched the most unlikely of places for cures to human disease. Eventually, Fleming's serendipitous 1928 discovery led to the development of penicillin. Today's scientists have taken a more proactive approach.

Oftentimes, their starting material is still as counterintuitive as a moldy plate...a new subset of scientists known as synthetic biologists are trying to turn single-celled organisms like bacteria and yeast into tiny chemical factories that can build these compounds from scratch...Jay Keasling, a chemical engineer at the University of California, Berkeley, is leading the pack...

Keasling's first target was malaria—a disease that kills more than 1 million people every year, mostly infants and young children from the world's poorest regions.

With a 90 percent cure rate, artemisinin is easily the most powerful antimalaria drug on the market. But extracting the clunky molecule from the sweet-wormwood plant that produces it is slow and expensive. In fact, the medication is so scarce that most of the world's 3 million malaria patients are dying for want of it.

Keasling's team inserted wormwood genes into a simple yeast cell, and then reprogrammed some of that cell's own genes to create a microorganism that can spin sugar into artemisinin...reducing the manufacturing costs from dollars to pennies per dose.

To make sure that patients actually saw those savings, Keasling ensure that no one, including him, could profit from his newly patented system.

"It's not that we're against companies making money," he says. "We just don't want them to gouge the poor." In March, Sanofi-Aventis signed on to scale up production of Keasling's customized yeast cells. The company expects to start churning out artemisinin by late 2010; it will sell the drug at cost...

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