Scientists at the U.S. Department of Energy's Brookhaven National Laboratory have discovered a new function in a plant enzyme that could help in designing new chemical catalysts. The enzyme catalyzes, or initiates, one of the cornerstone chemical reactions needed to synthesize organic molecules, including those found in lubricants, cosmetics, and those used as raw materials for making plastics.
The discovery was made in the team's ongoing research into enzymes that desaturate plant oils. These desaturase enzymes strip hydrogen atoms off specific adjacent carbon atoms in a hydrocarbon chain and insert a double bond between those carbon atoms. The group of John Shanklin had previously created a triple mutant version of a desaturase enzyme with interesting properties, and they were studying the three mutations separately to see what each one did. Two of the single mutant enzymes turned out to remove the double bond between adjacent carbon atoms and added an "OH" (hydroxyl group) to each carbon to produce a fatty acid with two adjacent hydroxyl groups.
The team's next goal is to obtain a crystal structure of the enzymes for them to learn how to control the configuration of lab-made catalysts that will mimic the plant-derived version.
(Source: Crop Biotech Update, International Service for Acquisition of Agri-Biotech Applications. www.isaaa.org)
Brookhaven Lab biochemist John Shanklin with retired biology associate Ed Whittle displaying a structural image of a desaturase enzyme that introduces adjacent hydroxyl groups into a fatty acid. This fatty acid can be used to synthesize a wide range of organic molecules, so the discovery of the plant enzyme may inspire the development of new "greener" industrial catalysts. Photo Source: Brookhaven National Laboratory.