Burkart and chemists in his laboratoryNicolas Kosa, Robert Haushalter and Andrew Smithfound a way to remove the chemical probe from this metabolic protein using an enzyme called a phosphodiesterase derived from the common bacterium Pseudomonas aeruginosa. Subsequent reattachment of a fatty acid analogue reconstituted the protein complex to its natural state. By repeating the process again and again, while examining the molecular changes in the fatty acid with nuclear magnetic spectroscopy, or NMR, during different metabolic stages, the scientists were able to detail the biochemical pathway of the fatty acid metabolism in a way they had never been able to do before.
"Without this tool, we would really have very limited ways of studying the dynamics of these fundamental metabolic processes," Burkart said. "This opened the door for us to finally examine in detail the fatty acid biosynthesis shared by algae, which you have to understand if you want to engineer ways to improve the quantity of oil that's made by algae or to make different types of oil molecules in algae that are better for biofuels."
The UC San Diego chemists also used NMR to verify that the process of chemically removing and attaching the chemical probes does not degrade or alter the protein in any way. "We've shown that we can do this iteratively, at least four or five times, without any degradation of the protein," said Burkart. "The protein remains very stable and can be studied very easily."
Because these same metabolic processes are shared by the metabolism of many natural products, including anti-cancer agents, antibiotics, and natural insecticides, Burkart said this new tool should have wide application in natural product chemistry labs.
"These are fundam
|Contact: Kim McDonald|
University of California - San Diego