Featured Research

from universities, journals, and other organizations

Researchers First To Directly Increase Enzyme’s Activity

Date:
March 23, 1999
Source:
University Of Arkansas
Summary:
A University of Arkansas chemist has become the first researcher to increase the activity of an enzyme that breaks down one of nature’s most abundant materials that can then be converted into ethanol — a potentially abundant source of environmentally friendly fuel.

FAYETTEVILLE, Ark. — A University of Arkansas chemist has become the first researcher to increase the activity of an enzyme that breaks down one of nature’s most abundant materials that can then be converted into ethanol — a potentially abundant source of environmentally friendly fuel.

Related Articles


Joshua Sakon, chemistry, other researchers from the University of Arkansas and scientists from the National Renewable Energy Laboratory in Golden, Colo. study the enzyme cellulase, which cleaves cellulose into glucose, a sugar that can be fermented into ethanol.

Intense research has focused on this process because cellulose found in plants accounts for about half the organic material on earth, which makes it potentially a vast renewable energy resource.

However, in the reaction that transforms the organic matter into fuel, the low activity of the enzyme cellulase acts as a bottleneck, slowing the whole procedure down. For at least ten years, scientists have sought ways to increase the enzyme’s activity, and thus its productivity — to no avail.

Sakon’s group increased the enzyme’s activity by 13 percent. The researchers will present their work today (March 21) at the American Chemical Society meeting in Anaheim, Calif.

Cellulase cuts the plant tissue cellulose into glucose — a simple sugar. It does so by attaching to the cellulose, clipping it and releasing the resulting sugar moelcules.

"Many people tried to come up with better scissors," Sakon said. He decided to focus instead on the enzyme structures that hold the cellulose in place while it’s being clipped. If these structures had a looser grip, he reasoned, they would release the sugars faster, increasing the reaction’s activity.

The researchers extracted cellulose from fast-growing yellow poplar trees. They used X-ray crystallography to examine the structure of the cellulase-cellulose interaction.

Then Sakon worked with University of Arkansas physical chemist Lothar Schaffer, using computer models to predict the impact of modifying the enzyme at certain sites.

The researchers then mutated the amino acid tyrosine 245, one of the biochemical "hands" that holds the cellulose in place. They substituted glycine, an amino acid that creates a weaker bond, or grip, at that site.

The resulting mutant increased the enzyme’s activity by 13 percent.

Sakon already is looking at the next experiment — perhaps trying mutations elsewhere in the enzyme’s "hold-and-release" region.

"Our experimental calculations showed we should have got a lot higher activity," Sakon said. "Now something else has become the rate-limiting step."


Story Source:

The above story is based on materials provided by University Of Arkansas. Note: Materials may be edited for content and length.


Cite This Page:

University Of Arkansas. "Researchers First To Directly Increase Enzyme’s Activity." ScienceDaily. ScienceDaily, 23 March 1999. <www.sciencedaily.com/releases/1999/03/990323050251.htm>.
University Of Arkansas. (1999, March 23). Researchers First To Directly Increase Enzyme’s Activity. ScienceDaily. Retrieved October 31, 2014 from www.sciencedaily.com/releases/1999/03/990323050251.htm
University Of Arkansas. "Researchers First To Directly Increase Enzyme’s Activity." ScienceDaily. www.sciencedaily.com/releases/1999/03/990323050251.htm (accessed October 31, 2014).

Share This



More Matter & Energy News

Friday, October 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

EU, Russia, Ukraine Seal Breakthrough Gas Accord

EU, Russia, Ukraine Seal Breakthrough Gas Accord

AFP (Oct. 31, 2014) Russia agrees to resume gas deliveries to war-torn Ukraine through the winter in an EU-brokered, multi-billion dollar deal signed by the three parties in Brussels. Duration: 01:10 Video provided by AFP
Powered by NewsLook.com
Relief After “gas War” Is Averted

Relief After “gas War” Is Averted

Reuters - Business Video Online (Oct. 31, 2014) A gas war between Russia and Ukraine has been averted. But as Hayley Platt reports a deal was only reached after Kiev's western creditors agreed to partly funding the deal. Video provided by Reuters
Powered by NewsLook.com
Jaguar Land Rover Opens $800 Million Factory in Britain

Jaguar Land Rover Opens $800 Million Factory in Britain

AFP (Oct. 30, 2014) British luxury car manufacturer Jaguar Land Rover opened a $800 million engine manufacturing centre in western England, creating 1,400 jobs. Duration: 00:45 Video provided by AFP
Powered by NewsLook.com
SkyCruiser Concept Claims to Solve Problem With Flying Cars

SkyCruiser Concept Claims to Solve Problem With Flying Cars

Buzz60 (Oct. 30, 2014) A start-up company called Krossblade says its SkyCruiser concept flying car solves the problem with most flying car concepts. Mara Montalbano (@maramontalbano) explains. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins