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:4/3/2017)... , April 3, 2017  Data captured ... engineering platform, detected a statistically significant association ... prior to treatment and objective response of ... potential to predict whether cancer patients will ... treatment, as well as to improve both pre-infusion ...
(Date:3/28/2017)... 28, 2017 The report "Video ... Monitors, Servers, Storage Devices), Software (Video Analytics, VMS), and ... Global Forecast to 2022", published by MarketsandMarkets, the market ... is projected to reach USD 75.64 Billion by 2022, ... The base year considered for the study is 2016 ...
(Date:3/23/2017)... 2017 Research and Markets has announced the ... Trends - Industry Forecast to 2025" report to their offering. ... The Global ... of around 8.8% over the next decade to reach approximately $14.21 ... market estimates and forecasts for all the given segments on global ...
Breaking Biology News(10 mins):
(Date:7/20/2017)... Canada (PRWEB) , ... July 20, 2017 , ... Dr. ... announced the winning recipients of the 2017 IAC Awards at the 22nd World Congress ... the committee also named four faculty to receive the Distinguished Fellowship Awards. , Dr. ...
(Date:7/20/2017)... ... July 20, 2017 , ... Corporate Directors Forum is recognizing six ... Director of the Year Awards. , The awards will be presented Thursday, September 7th, ... event celebrates directors who have made significantly positive contributions in the boardrooms of some ...
(Date:7/18/2017)... ... July 18, 2017 , ... G-CON today announced that ... Office for its Patent Applications 14/858,857 and 13/669,785 both entitled Modular, Self-Contained, Mobile ... further expand the protection of G-CON’s R&D investments and validate the G-CON platform ...
(Date:7/17/2017)... ... 2017 , ... The Academy of Model Aeronautics (AMA) will host Aviation Adventure ... take place from 9 a.m. to 2 p.m. at the International Aeromodeling Center in ... Aviation Adventure Day will be packed with entertaining activities for the entire family. Attendees ...
Breaking Biology Technology: