Emory University: Global Warming
PLANT ENZYME EFFICIENCY MAY HOLD KEY TO GLOBAL WARMING - 02/15/06
Global warming just may have met its match. In research recently completed at Emory University School of Medicine, scientists have discovered a mutant enzyme that could enable plants to use and convert carbon dioxide more quickly, effectively taking more of that gas out of the atmosphere.
The findings were published online on January 19 and will appear in the February issue of the journal Protein Engineering Design and Selection. Ichiro Matsumura, PhD, assistant professor of biochemistry at Emory University School of Medicine, is the senior author and principal investigator. The lead author is research specialist Monal R. Parikh.
During photosynthesis, plants and some bacteria convert sunlight and carbon dioxide into usable chemical energy. Scientists have long known that this process relies on the enzyme rubulose bisphosphate carboxylase/oxygenase, also called RuBisCO. While RuBisCO is the most abundant enzyme in the world, it is also one of the least efficient. As Dr. Matsumura says, all life pretty much depends on the function on this enzyme. It actually has had billions of years to improve, but remains about a thousand times slower than most other enzymes. Plants have to make tons of it just to stay alive.
RuBisCO's inefficiency limits plant growth and stops organisms from using and assimilating all the carbon dioxide in the atmosphere, even as the amount of gas in the atmosphere continues to grow. The resulting gas buildup is one cause of global warming.
A 2004 report by the National Science Foundation estimates that atmospheric carbon dioxide concentrations remained steady at between 200 and 280 parts per million for thousands of years, but that carbon dioxide levels have risen dramatically since the Industrial Revolution of the 1800s, leading to 380 parts per million of carbon dioxide in the atmosphere today.
