Originally created 05/18/99

'High-speed evolution' shows promise



SEATTLE -- It's a revolution in evolution that Charles Darwin never dreamed of: Biotechnology companies are conducting high-speed evolution in test tubes to create everything from sophisticated laundry detergents to novel drugs.

Called directed evolution, the process could prove one of the most important steps in biotechnology since genetic engineering. It's getting a lot of attention at a meeting of 5,000 biotechnologists this week in Seattle.

The idea is to discover in nature substances that perform in a certain way but have drawbacks -- such as a cancer-fighting protein that can be used only in small doses because of side effects -- and force them to evolve rapidly to be better.

"It's optimizing the best nature can provide," explained Jay Short, president of Diversa Inc., which is trying to improve blood transfusions with the process.

The first commercial product derived from directed evolution is an enzyme that fights tough laundry stains better than a previous detergent ingredient. But companies are studying dozens of others -- from anti-cancer drugs and better vaccines to a fade-resistant laundry enzyme that promises to let people wash a red shirt together with underwear without their socks turning pink.

In biotechnology, the process until now has been: "Here are genes from nature, and what can I do to squash these into a workable commercial product?" said Russell Howard, president of Maxygen Inc., a leader in the field.

But redesigning genes or the proteins they produce to fit a specific need is difficult and expensive because scientists simply don't understand enough about how these complex substances work, said Frances Arnold, a directed evolution pioneer at the California Institute of Technology.

Many scientists believe nature pressures species to adapt, forcing diversification and survival of the fittest.

With directed evolution, biotechnologists use various laboratory methods to pressure genes to mutate in thousands of ways, doing in days or weeks what can take nature years. It took decades for certain bacteria to evolve to resist antibiotics, for instance, but companies in days can create new supergerms to test new antibiotics.

In the pipeline:

-- Diversa is evolving enzymes to strip certain molecules from blood, thus converting Type A and Type B blood donations into the Type O blood that almost everyone can use.

-- Mr. Arnold evolved an enzyme to help synthesize antibiotics more inexpensively and with less pollution.

-- University of Illinois scientists just reported a way to evolve certain immune system cells to better fight autoimmune diseases in which the body attacks itself -- even AIDS. Also under study are anti-cancer drugs and enzymes to strengthen chemotherapy.