Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Neutron scattering explains how myoglobin can perform without water

02.08.2012
Understanding will help protein's potential application in biochemical gas sensors or in state-of-the-art wound dressing

Proteins do not need to be surrounded by water to carry out their vital biological functions, according to scientists from the Institut de Biologie Structurale (IBS) in Grenoble, the University of Bristol, the Australian National University, the Institut Laue Langevin and the Jülich Centre for Neutron Science.

In a new paper, published in the Journal of the American Chemical Society, the team used a state-of-the-art neutron scattering technique to demonstrate that when myoglobin, an oxygen-binding protein found in the muscle tissue of vertebrates, is enclosed in a sheath of surfactant molecules, it moves in the same way as when it is surrounded by water. These motions are essential if a protein is to perform its biological function, and their findings make proteins a viable material for use in new wound dressings or even as chemical gas sensors.

Water is the natural environment for soluble proteins and an integral part of their structures which allows them to carry out their specific function. It had been perceived for many years that proteins required water or another solvent in order to function. But in 2010, the Bristol team proved that by grafting polymer chains onto the protein surface, it was possible to produce solvent- and water-free myoglobin liquids that could still perform their biological roles. Scientists have now demonstrated that protein dynamics is the reason why.

Myoglobin is common to almost all mammals and responsible for the red colour of raw meat. Like all soluble proteins, its surface is covered with water molecules. In this study researchers wanted to assess whether the protein structure could still move and continue to bind oxygen if all the water was completely removed and replaced by synthetic molecules.

The team analysed three samples, a wet sample (the protein in water), a dry sample (the dehydrated protein) and a dry protein-polymer hybrid sample where the water molecules had been replaced by synthetically crafted polyethylene glycol-based polymer surfactant molecules. Using a technique called incoherent neutron scattering at the Institut Laue Langevin (ILL) in Grenoble, France, and at the Jülich Centre for Neutron Science at FRMII, Garching, Germany, the team was able to monitor the motions in the protein and in the polymer surfactant separately. This separation has been made possible by specific labelling, carried out in a dedicated deuteration laboratory at the ILL, by which either polymer or protein motions are masked by replacing hydrogen with its heavier isotope, deuterium.

What they found was that the myoglobin molecules surrounded by polymer moved just as well as the wet sample, and that the dry sample had very little mobility. Knowing that proteins can function outside of water opens them up to use in real life applications because it shows that there are other alternatives if water is unavailable. Examples of where they could be used include biochemical gas sensors, as myoglobin can bind carbon monoxide molecules.

Another potential application is in the development of new wound dressings, where the liquid protein could be applied either internally and externally to the wound to reduce healing time by supplying oxygen or other essential chemicals to the damaged tissue.

Adam Perriman of the University of Bristol's School of Chemistry said: "These discoveries have increased our fundamental understanding of proteins and how they behave, which could create many new opportunities for their application in industrial processing and in medical technologies. The fact that our proteins can happily perform their function outside of water, a substance generally thought to be vital for life, really drives home just how robust these biological nanomachines are."

Martin Weik of the Institut de Biologie Structurale explained: "Neutron scattering techniques are excellent for studying the dynamics of proteins and of their environment. The world-class neutron scattering facilities at the ILL and the FRM II allow us to analyse how proteins move, thus complementing the single snapshots of their structures provided by crystallography."

Earlier this month, Martin Weik and colleagues from the IBS, the ILL, the University of California, the Australian Institute of Science and Technology Organisation and the Jülich Centre for Neutron Science at FRMII, applied these techniques to an intrinsically disordered protein (IDP) called tau, to try and understand how its flexibility and its interactions with water differ from ordered proteins such as myoglobin.

They found that the coupling of the disordered tau protein with water motions was much tighter than for folded proteins. IDPs are of significant interest in a medical context because they can aggregate and cluster together to create the amyloid fibrils behind neuro-degenerative diseases such as Parkinson's and Alzheimer's. Whilst the ordered structure of folded proteins makes it possible to develop drugs that fit into the protein like a key in a lock, the conformational variability of an intrinsically disordered protein like tau makes it more difficult. A more in-depth understanding of their dynamics is required and the discovery of tight coupling with water motions is a significant step forward.

Hannah Johnson | EurekAlert!
Further information:
http://www.bristol.ac.uk

More articles from Life Sciences:

nachricht Selectively Reactivating Nerve Cells to Retrieve a Memory
01.06.2020 | Universität Heidelberg

nachricht CeMM study reveals how a master regulator of gene transcription operates
01.06.2020 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Rolling into the deep

Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...

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

Black nitrogen: Bayreuth researchers discover new high-pressure material and solve a puzzle of the periodic table

29.05.2020 | Materials Sciences

Argonne researchers create active material out of microscopic spinning particles

29.05.2020 | Materials Sciences

Smart windows that self-illuminate on rainy days

29.05.2020 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>