Navigation Links
In an enzyme critical for life, X-ray emission cracks mystery atom
Date:11/17/2011

ITHACA, N.Y. - Like a shadowy character just hidden from view, a mystery atom in the middle of a complex enzyme called nitrogenase had long hindered scientists' ability to study the enzyme fully.

But now an international team of scientists led by Serena DeBeer, Cornell assistant professor of chemistry and chemical biology, has pulled back the curtain using powerful synchrotron spectroscopy and computational modeling to reveal carbon as the once-elusive atom.

The research was published online Nov. 17 in the journal Science.

"For chemists, one of the first steps you want to be able to take is to actually model the site," said DeBeer. "It turns out that the chemistry of how this cluster behaves will be different depending on what atom is in the middle. This is the first step toward trying to unravel its mechanism."

Why nitrogenase? In nature, all life requires the element nitrogen from the atmosphere to form amino acids and build proteins. Bacteria need to convert nitrogen to ammonia as a precursor to more complex biosynthetic processes. The enzyme that catalyzes all this is nitrogenase, and it does it by breaking one of the strongest bonds in chemistry the nitrogen triple bond.

The chemical industry has figured out how to convert nitrogen to ammonia in high-temperature and high-pressure industrial environments. There's a fascination with understanding how the enzyme makes this same process work in nature, DeBeer said.

DeBeer and colleagues honed in on a subset of atoms in the relatively large enzyme, called the iron-molybdenum cofactor, which was thought to be the site where dinitrogen (N2) gets converted to ammonia, and where the mystery atom is situated inside.

The team used a method called X-ray emission spectroscopy (XES) at the Stanford Synchrotron Radiation Light Source to excite the electrons in the cofactor's iron cluster and to watch how electrons refilled the spots, called "holes," they left behind. The holes were sometimes filled by an electron belonging to a neighboring atom emitting X-ray signatures with distinct ionization potentials that would distinguish between different kinds of atoms.

This was how it was revealed that the cofactor contained a carbon atom, rather than a nitrogen or an oxygen atom, that was bound to the iron atoms in the cluster.


'/>"/>
Contact: Blaine Friedlander
bpf2@cornell.edu
607-254-8093
Cornell University
Source:Eurekalert

Related biology news :

1. Atomic-resolution views suggest function of enzyme that regulates light-detecting signals in eye
2. New insight into the controls on a go-to enzyme
3. UNC scientists teach enzyme to make synthetic heparin in more varieties
4. Rare disease provides clues about enzyme role in arrhythmias
5. Brain enzyme may play key role in controlling appetite and weight gain
6. Newly found enzymes may play early role in cancer
7. HWI scientist first in world to unravel structure of key breast cancer target enzyme
8. Researchers first to see reactive oxygen species in vital enzyme
9. Disabling enzyme allows mice to gorge without becoming obese, new study finds
10. Structure of enzyme against chemical warfare agents determined
11. Researchers find pathway and enzyme unique to tularemia organism
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/31/2016)...   LegacyXChange, Inc. ... LegacyXChange is excited to release its first ... be launched online site for trading 100% guaranteed authentic ... also provide potential shareholders a sense of the value ... industry that is notorious for fraud. The video is ...
(Date:3/23/2016)... Massachusetts , March 23, 2016 /PRNewswire/ ... im Interesse erhöhter Sicherheit Gesichts- und Stimmerkennung ... Xura, Inc. (NASDAQ: MESG ), ... bekannt, dass das Unternehmen mit SpeechPro zusammenarbeitet, ... aus der Finanzdienstleistungsbranche, wird die Möglichkeit angeboten, ...
(Date:3/21/2016)... 2016 Unique technology combines ... superior security   Xura, Inc. ... secure digital communications services, today announced it is working ... enterprise customers, particularly those in the Financial Services Sector, ... authentication within a mobile app, alongside, and in combination ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... , ... Supplyframe, the Industry Network for electronics hardware design ... Located in Pasadena, Calif., the Design Lab’s mission is to bring together inventors ... and brought to market. , The Design Lab is Supplyframe’s physical representation of ...
(Date:6/23/2016)... ... June 23, 2016 , ... In a new case report published today ... a patient who developed lymphedema after being treated for breast cancer benefitted from an ... paradigm for dealing with this debilitating, frequent side effect of cancer treatment. ...
(Date:6/23/2016)... June 23, 2016  Blueprint Bio, a company dedicated ... the medical community, has closed its Series A funding ... . "We have received a commitment from ... we need to meet our current goals," stated ... the runway to complete validation on the current projects ...
(Date:6/23/2016)... , June 23, 2016 On Wednesday, ... at 4,833.32, down 0.22%; the Dow Jones Industrial Average edged ... closed at 2,085.45, down 0.17%. Stock-Callers.com has initiated coverage on ... ), Nektar Therapeutics (NASDAQ: NKTR ), Aralez Pharmaceuticals ... (NASDAQ: BIND ). Learn more about these stocks ...
Breaking Biology Technology: