Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Insight into enzyme's 3-D structure could cut biofuel costs

19.05.2017

Neutron crystallography maps LPMOs that break down fibrous cellulose

Using neutron crystallography, a Los Alamos research team has mapped the three-dimensional structure of a protein that breaks down polysaccharides, such as the fibrous cellulose of grasses and woody plants, a finding that could help bring down the cost of creating biofuels. The research focused on a class of copper-dependent enzymes called lytic polysaccharide monooxygenases (LPMOs), which bacteria and fungi use to naturally break down cellulose and closely related chitin biopolymers.


Understanding the structure of an enzyme that helps bacteria break down cellulose and chitin in woody plant fibers can aid in developing better biofuels. In this image, an electron density map (gray) shows the structure of the active site center of the LPMO enzyme under study, depicting a dioxygen molecule (red stick) bound to a catalytic copper ion (bronze).

Credit: LANL

"In the long term, understanding the mechanism of this class of proteins can lead to enzymes with improved characteristics that make production of ethanol increasingly economically feasible," said Julian Chen, a Los Alamos National Laboratory scientist who participated in the research.

A multi-institution team used the neutron scattering facility at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory and the Advanced Light Source (ALS) synchrotron X-ray source at Lawrence Berkeley National Laboratory to study LPMO. Both SNS and ALS are DOE Office of Science User Facilities.

Los Alamos Bioscience Division scientists Chen, Clifford Unkefer, and former postdoctoral fellow John Bacik, working with collaborators at Oak Ridge National Laboratory, Lawrence Berkeley Laboratory, and the Norwegian University of Life Sciences, solved the structure of a chitin-degrading LPMO from the bacterium Jonesia denitrificans (JdLPMO10A). The team's results are published in the journal Biochemistry.

One of the biggest challenges biofuel scientists face is finding cost-effective ways to break apart polysaccharides such as starches and cellulose, which are widely distributed in plants, into their subcomponent sugars for biofuel production. LPMO enzymes, which are seen as key to this process, use a single copper ion to activate oxygen, a critical step for the enzyme's catalytic degrading action.

While the specific mechanism of LPMO action remains uncertain, it is thought that catalysis involves initial formation of a superoxide by electron transfer from the reduced copper ion. By understanding the location of the copper ion and the constellation of atoms near it, the researchers hope to elucidate more about the enzyme's function. To do this, they rely on first determining the structure of the enzyme.

Although a number of X-ray crystallographic structures are currently available for LPMOs from fungal and bacterial species, this new structure is more complete. The investigators used X-ray crystallography to resolve the three-dimensional structure in clear detail of all the atoms except for hydrogens, the smallest and most abundant atoms in proteins. Hydrogen atom positions are important for elucidating functional characteristics of the target protein and can best be visualized using a neutron crystallography. The investigators used this complementary technique, to determine the three-dimensional structure of the LPMO, but highlighting the hydrogen atoms.

Notably, in this study the crystallized LPMO enzyme has been caught in the act of binding oxygen. Together with the recent structures of LPMOs from a wide variety of fungal and bacterial species, the results of this study indicate a common mechanism of degrading cellulosic biomass despite wide differences in their protein sequences. This study has furthered insight into the mechanism of action of LPMOs, particularly the role of the copper ion and the nature of the involvement of oxygen.

Biofuels research is part of the Los Alamos National Laboratory's mission focus on integrating research and development solutions to achieve the maximum impact on strategic national security priorities such as new energy sources.

###

The paper: Neutron and Atomic Resolution X-ray Structures of a Lytic Polysaccharide Monooxygenase Reveal Copper-Mediated Dioxygen Binding and Evidence for N-Terminal Deprotonation.

Funding: The Los Alamos component of the research was funded by the DOE Office of Science and imaging analysis was performed at DOE Office of Science user facilities. The work was also supported by The Research Council of Norway and the Norwegian Academy of Science and Letters.

About Los Alamos National Laboratory

Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is operated by Los Alamos National Security, LLC, a team composed of Bechtel National, the University of California, BWX Technologies, Inc. and URS Corporation for the Department of Energy's National Nuclear Security Administration.

Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health and global security concerns.

Nancy Ambrosiano | EurekAlert!

More articles from Life Sciences:

nachricht Enduring cold temperatures alters fat cell epigenetics
19.04.2018 | University of Tokyo

nachricht Full of hot air and proud of it
18.04.2018 | University of Pittsburgh

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

Im Focus: The Future of Ultrafast Solid-State Physics

In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.

Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Diamond-like carbon is formed differently to what was believed -- machine learning enables development of new model

19.04.2018 | Materials Sciences

Electromagnetic wizardry: Wireless power transfer enhanced by backward signal

19.04.2018 | Physics and Astronomy

Ultrafast electron oscillation and dephasing monitored by attosecond light source

19.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>