Researchers at the University of Washington have discovered a new method of regulating how proteins bind with specific molecules, a finding that gives scientists a size-selective switch to turn protein function on and off and moves a step closer to one of the holy grails of bioengineering.

The discovery, scheduled to appear in the journal Nature this week, has a number of possible applications in fields ranging from medical diagnostics to environmental sensing and computer science.

This is what we call a platform technology, said Patrick Stayton, associate professor of bioengineering. He and colleague Allan S. Hoffman, professor of bioengineering, lead the research group. The basic idea is to be able to turn proteins on and turn them off, which has been one of the holy grails of bioengineering. Its very exciting and can apply in a lot of different areas. The latest finding builds on earlier work by the group exploring the use of so-called smart polymers to control access to binding sites on proteins. The polymers are described as smart because they sense their environment and alter their properties according to changes in external conditions, such as temperature, acidity and light.

In the earlier research, Stayton, Hoffman and their colleagues attached tiny smart polymer chains next to active sites on a protein. The idea was that as the polymer changed its properties, it would collapse into a compact globule to block the site, Stayton said.

When it extended, it would allow a molecule that recognizes the site to attach. And if you collapsed the polymer and a molecule were already attached, the collapsing polymer could kick it off the site.

The key, he said, was that the process was reversible, allowing scientists to control proteins in grabbing specific molecules, then letting them go on command. The problem was that, with the polymer attached so closely to the site, the process worked only for small molecules. The polymer, ev
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Contact: Rob Harrill
rharrill@u.washington.edu
206-543-2580
University of Washington
30-Apr-2001