Bayreuth, Germany (dpa) – In a big, barn-like hall made of wood in southern Germany, situated far away from any roads, are eight tonnes’ worth of super magnet – part of one of the world’s most precise measuring devices, a nuclear magnetic resonance spectrometer.
“Using electromagnetic high frequency impulses, we disturb the balance of atomic nuclei,” explains Paul Roesch, a professor of biopolymers at the University of Bayreuth. “With the signals produced, we can calculate the 3-D structure of molecules.”
Metal would disturb measurements, as would passing vehicles, which is why the super magnet is housed in wood and kept away from the road.
What the professor and his colleagues are investigating with the 25-million-euro (31-million-dollar) measuring device is proteins.
Even though the proteins they are looking at are a thousand times smaller than a bacterium – a size unimaginable to the human brain – the NMR spectrometer makes it possible to measure them.
Just half a millilitre of protein solution in an unassuming glass test tube is enough for the colossal instrument to deliver a result, which appears at the end of the day as a collection of small dots on a computer screen.
The intensity of the dots illustrates the distance between the individual atom’s nuclei. It takes a lot of computing power to create a three-dimensional image of a protein out of those dots.
“The fact that we can use commercially available computers for that is thanks to gamers, among others,” says Roesch. Partly due to the demands of gamers for computing power necessary for their hobby, the industry has developed computers with extremely powerful processors.
One of the biopolymer department’s most important areas of research is establishing the chemical structure of allergens, for example the protein of birch tree pollen, which makes many people sneeze.
The 3-D structure that the computer has produced of the pollen looks like a crumpled-up ribbon with straight and puckered sections.
Roesch and his colleagues have been studying the pollen for more than 20 years.
Working together with the Paul Ehrlich Institute, which researches biomedicines like vaccines, the scientists have succeeded in explaining cross-reactivity – ie, why people who are allergic to one thing may be allergic to others too.
For example, those who are allergic to birch pollen often develop allergies to apples, kiwis, carrots, cherries or hazelnuts.
“That’s because they all have a very similar 3-D structure,” explains Stefan Vieths, vice president of the institute. The chemical structure of the allergen is very important, he adds.
For one, it helps with understanding the mechanism of an allergy, and secondly, it can help improve hyposensitization treatments, which involve administering patients with increasingly high doses of an allergen so that the immune system learns it isn’t dangerous.
“If we know what structures on the protein’s surface are responsible for the allergy, we can develop appropriate immunization therapies,” says Vieths.
Using so-called protein engineering, scientists can change the surface of the protein in drugs to produce the effect of an allergen and at the same time reduce side effects.
According to Vieths, it could also theoretically be possible to use gene technology to make allergens contained in plants harmless, allowing those who suffer from allergies to start eating tomatoes, cherries and kiwis again.
There are various methods available today by which scientists can examine the smallest building blocks of life, including X-ray crystallography and electron microscopes.
But for them to work, the proteins have to remain still, either in the form of crystals or after having been frozen.
“NMR spectroscopy is the only method which allows [us] to examine the structure and dynamic of proteins in a solution,” says Roesch.
Scientists can, for example, observe how proteins change over time, or how they interact with other proteins. That could include examining whether carrot allergens are rendered harmless by cooking.
The mechanisms by which certain proteins set off allergies is still unknown to science.
“One question that we are looking at is whether the allergenic properties of proteins are affected by small attached molecules,” says Roesch.
In the case of birch pollen, that could include flavonoids – small molecules that occur in all plants and fulfil different functions.