Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chemists create synthetic cytochromes

08.10.2002


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."

James E. Kloeppel | EurekAlert!
Further information:
http://www.uiuc.edu/

More articles from Life Sciences:

nachricht Across the cell membrane
02.06.2020 | University of Texas at Austin, Texas Advanced Computing Center

nachricht Reducing inflammation boosts cognitive recovery after stroke, may extend treatment window
02.06.2020 | Medical University of South Carolina

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New measurement exacerbates old problem

Two prominent X-ray emission lines of highly charged iron have puzzled astrophysicists for decades: their measured and calculated brightness ratios always disagree. This hinders good determinations of plasma temperatures and densities. New, careful high-precision measurements, together with top-level calculations now exclude all hitherto proposed explanations for this discrepancy, and thus deepen the problem.

Hot astrophysical plasmas fill the intergalactic space, and brightly shine in stellar coronae, active galactic nuclei, and supernova remnants. They contain...

Im Focus: Biotechnology: Triggered by light, a novel way to switch on an enzyme

In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".

Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...

Im Focus: New double-contrast technique picks up small tumors on MRI

Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.

researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...

Im Focus: I-call - When microimplants communicate with each other / Innovation driver digitization - "Smart Health“

Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.

When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...

Im Focus: When predictions of theoretical chemists become reality

Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.

Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

Joined nano-triangles pave the way to magnetic carbon materials

02.06.2020 | Materials Sciences

DC smart grids for production halls

02.06.2020 | Power and Electrical Engineering

Selectively Reactivating Nerve Cells to Retrieve a Memory

02.06.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>