Featured Research

from universities, journals, and other organizations

Chemists Create Synthetic Cytochromes

Date:
October 8, 2002
Source:
University Of Illinois At Urbana-Champaign
Summary:
When animals metabolize food or when plants photosynthesize it, electrons are moved across cell membranes. The "extension cords" of this bioelectrical circuit are mostly iron-containing proteins called cytochromes. Chemist Kenneth S. Suslick and colleagues at the University of Illinois at Urbana-Champaign have created synthetic cytochromes by making a small cyclic peptide that binds to the iron millions of times more strongly than without the peptide.

CHAMPAIGN, Ill. -- When animals metabolize food or when plants photosynthesize it, electrons are moved across cell membranes. The "extension cords" of this bioelectrical circuit are mostly iron-containing proteins called cytochromes.

Chemist Kenneth S. Suslick and colleagues at the University of Illinois at Urbana-Champaign have created synthetic cytochromes by making a small cyclic peptide that binds to the iron millions of times more strongly than without the peptide. The scientists report their discovery in a paper in the Oct. 23 issue of the Journal of the American Chemical Society.

Cytochromes are heme proteins; that is, the iron is held in the central hole of a doughnut-shaped heme. Related to hemoglobin and myoglobin -- the red-colored proteins that carry and store oxygen in blood and muscles -- cytochromes carry electrons rather than oxygen atoms.

"The heme is held very tightly in heme proteins, most commonly by bonds between the iron ion and the amino acid histidine," said Suslick, a William H. and Janet Lycan Professor of Chemistry at Illinois. "This bond is much stronger in proteins than it is for a heme binding free histidine. This makes cytochromes among the most stable of all proteins."

Suslick and his colleagues expected that a cyclic peptide would hold on to the iron ion heme like a tight ring on a finger. In fact, the researchers found that their cyclic peptide binds to heme 6,000 times more strongly than to two half-sized peptides that are not linked together, and 4 million times more strongly than histidine itself.

"Most of this effect is called 'preorganization,'" Suslick said. "By preforming the peptide ring, we make it much easier for the peptide to bind the heme. In addition, the heme stabilizes the structure of the cyclic peptide by making it fold into a perfect helix."

The synergism of these effects helps explain the important role that heme plays in making heme proteins so very stable. The heme holds the protein structure together at the same time that the protein holds onto the heme.

Such synthetic cytochromes may have pharmaceutical uses in the future.

"These heme-peptides are likely to carry electrons and ions across cell membranes," Suslick said. "This could make them very effective antibiotics, many of which kill bacteria by just this kind of transport."

The National Institutes of Health funded this work.


Story Source:

The above story is based on materials provided by University Of Illinois At Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University Of Illinois At Urbana-Champaign. "Chemists Create Synthetic Cytochromes." ScienceDaily. ScienceDaily, 8 October 2002. <www.sciencedaily.com/releases/2002/10/021008065724.htm>.
University Of Illinois At Urbana-Champaign. (2002, October 8). Chemists Create Synthetic Cytochromes. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2002/10/021008065724.htm
University Of Illinois At Urbana-Champaign. "Chemists Create Synthetic Cytochromes." ScienceDaily. www.sciencedaily.com/releases/2002/10/021008065724.htm (accessed September 1, 2014).

Share This




More Matter & Energy News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com
Breakingviews: India Coal Strained by Supreme Court Ruling

Breakingviews: India Coal Strained by Supreme Court Ruling

Reuters - Business Video Online (Aug. 26, 2014) An acute coal shortage is likely to be aggravated as India's supreme court declared government coal allocations illegal, says Breakingviews' Peter Thal Larsen. Video provided by Reuters
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:
from the past week

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