Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

On the way to a biological alternative

14.07.2017

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase. Now the group is introducing the first three-dimensional structural analysis of the enzyme variant that contains vanadium.


The catalytic center of vanadium nitrogenase: an iron-vanadium cofactor with an unusual carbonate ligand.

Graphic: Oliver Einsle

Within the scope of preparing his doctoral thesis, Daniel Sippel succeeded in producing and crystallizing vanadium nitrogenase. Taking this as his basis, he used x-ray diffraction experiments to elucidate its spatial structure at the level of atomic resolution.

The team's long term goal is to make nitrogenase biotechnologcially useful in order to develop alternatives to industrial chemical processes. The researchers have presented their findings in the scientific journal "Nature Chemical Biology."

The element nitrogen (N) is a key component of all organic macromolecules. Its availability in the biosphere is limited by the fact that the global occurrence of nitrogen is confined largely to the gas N2 in the atmosphere. The stability of N2 furthermore makes it inaccessible to almost all organisms. Biologically available nitrogen for agricultural fertilizer has been made since 1906 using the Haber-Bosch process.

This industrial process converts atmospheric nitrogen (N2) to ammonia through a reaction with hydrogen. Its significance is so important today because food production for more than half of the world's people can only be guaranteed with the aid of nitrogen fertilizers.

In nature, only one enzyme – bacterial nitrogenase – can achieve the same reaction, but without emitting excess nitrogen compounds into the environment, or in other words, leaching of nitrates into groundwater. Yet until now, the function of this complex, metal-containing enzyme system which contains metal has only been partially explained.

Einsle's team has already taken a significant step towards greater understanding of nitrogenase. The researchers were able to inhibit the activity of the enzyme using the toxic gas carbon monoxide (CO) to show how the inhibitor binds to the iron molybdenum cofactor (FeMoco). Known as the core of nitrogenase, it has been named for the elements it contains.

FeMoco can catalyze the reaction of nitrogen and hydrogen in a natural version of the Haber-Bosch process. At the same time it was known that a variant of nitrogenase containing vanadium rather than molybdenum in its active center and therefore called FeVco can also convert carbon monoxide.

The products of this reaction are reduced carbon compounds in the form of short carbon chains. This reaction is the enzymatic version of a second significant chemical process – Fischer-Tropsch synthesis of hydrocarbons which can be used on a large scale to synthesize fuels from industrial waste gases, for instance.

Vanadium nitrogenase found in soil bacteria can in its natural setting perform the same synthesis that is only possible in industrial processes with the aid of extreme pressures and high temperatures. The Haber-Bosch and Fischer-Tropsch processes are annually used to convert hundreds of millions of tons of the respective gases – N2 and CO – making the possibility of a sustainable, biological alternative of considerable scientific interest.

During the research work, it became apparent that most parts of the architecture of the enzyme were similar to the "original" containing molybdenum. Nevertheless, there is in important distinction that sets them apart – the atomic structure of the catalytic cofactor. Sippel and Einsle found that a vanadium ion replaces the molybdenum ion in FeVco, and includes an additional replacement of a bridging sulfide ion with a chemically very different carbonate anion (µ-1,3 carbonate -- bridging ligand). What initially appears to be a slight difference has far-reaching effects on the geometric and electronic structure of the cofactor.

The research is being funded by the European Research Council (ERC) and the German Research Foundation (DFG) within the framework of the research training group 1976 "Functional Diversity of Cofactors" of the University of Freiburg and the Priority Program "Iron-Sulfur for Life."

Original publication:
Daniel Sippel & Oliver Einsle (2017): The structure of vanadium nitrogenase reveals an unusual bridging ligand. In: Nature Chemical Biology.
DOI: 10.1038/nchembio.2428

Contact:
Prof. Dr. Oliver Einsle
Institute of Biochemistry / BIOSS Centre for Biological Signalling Studies
University of Freiburg
Tel.: 0761/203-6058
E-Mail: einsle@biochemie.uni-freiburg.de

Weitere Informationen:

https://www.pr.uni-freiburg.de/pm-en/2017/on-the-way-to-a-biological-alternative

Rudolf-Werner Dreier | idw - Informationsdienst Wissenschaft

More articles from Life Sciences:

nachricht Modern technologies meet ancient treasures
13.07.2017 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP

nachricht New study on the regulation of seed dormancy in plants / Researchers decode function of protein
13.07.2017 | Westfälische Wilhelms-Universität Münster

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

Im Focus: Efficient and intelligent: Drones get to grips with planning the delivery of goods

In 2013, Amazon was one of the first to declare the intention to work towards the automated delivery of goods by small autonomous helicopters. A multi-disciplinary research team at the Alpen-Adria-Universität assembled by Christian Bettstetter and Friederike Wall is due to deliver initial insights on the efficient operation of (self-organised) delivery of goods. Doctoral student Pasquale Grippa will present the results at the conference “Robotics: Science and Systems”, which is scheduled to take place at the Massachusetts Institute of Technology (MIT) from July 12th.

“We are analysing a system in which customers order goods that are stored in depots and the subsequent deliveries are made by drones”, Christian Bettstetter...

Im Focus: Magic off the cuff

Moving things with a wave of the hand: thanks to Empa technology this dream could soon become real. A sensor made of piezo-resistive fibers integrated in a wristband measures wrist movements and converts them into electrical signals. This can be used to steer drones or other electronic devices without a remote control.

A wave to the left: the drone moves to the left. A wave to the right: the drone turns right. Clench your hand into a fist and it lands gently on the table. No,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

The technology with a feel for feelings

12.07.2017 | Event News

Leipzig HTP-Forum discusses "hydrothermal processes" as a key technology for a biobased economy

12.07.2017 | Event News

Rediscovering our Galaxy

07.07.2017 | Event News

 
Latest News

On the way to a biological alternative

14.07.2017 | Life Sciences

The 1 trillion tonne iceberg

13.07.2017 | Earth Sciences

Researchers overcome suppression of immune response against bacterial pathogens

13.07.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>