Proteins are the main molecular machines in our bodies. They perform a wide range of functions, from digesting and processing nutrients, converting energy and aiding cell structure to transmitting signals in cells and the whole body. In order to perform these highly specific functions, proteins have to adopt a well-defined, three-dimensional structure. Remarkably, in most cases they find this structure unaided once they have been formed out of their individual building blocks, amino acids, as a long chain molecule in the cell.
However, the process of protein folding can also go wrong, which means the proteins affected are no longer able to perform their function. In some cases, this can even have much more serious consequences if these misfolded proteins clump and trigger neurodegenerative diseases such as Alzheimer’s or Parkinson’s disease.
In the course of evolution, a crucial factor in the development of proteins has thus been to avoid such “misfolding processes”. However, this is no easy task since the same molecular interactions that stabilize the correct structure of the individual proteins can also bring about interactions between protein molecules, causing them to misfold.
Using a special spectroscopic method called single-molecule fluorescence, researchers from the Universities of Zurich and Cambridge have now studied the circumstances under which misfolding occurs. The team headed by Prof. Benjamin Schuler from the University of Zurich studied sections, or “domains”, of the largest protein in our bodies, titin, which helps the stability and elasticity of the muscle fibers. It is assumed that individual titin domains can unfold while the muscle is heavily exerted to avoid damaging the muscle tissue. When the muscle relaxes again, however, there is a danger that these unfolded domains might fold incorrectly. There is also a similar risk for other multidomain proteins.
For their study, the researchers attached small dye molecules as probes in the protein. “Using our laser-spectroscopic method we were able to determine distances on a molecular scale, i.e. down to a few millionths of a millimeter, through the energy transfer between the probes,” explains Prof. Schuler. This enabled the structures of correctly and misfolded proteins to be distinguished and thus the proportion of misfolding determined.
“The study of different titin domains in our experiments revealed that the probability of misfolding increases if neighboring domains are very similar in the sequence of their amino acids,” says Prof. Schuler. This is apparently the reason why neighboring domains in proteins have a limited degree of similarity. “This seems to be a key evolutionary strategy to avoid protein misfolding and thus guarantee their maximum functionality,” says Schuler.
Complementing conventional antibiotics
24.05.2018 | Goethe-Universität Frankfurt am Main
Building a brain, cell by cell: Researchers make a mini neuron network (of two)
23.05.2018 | Institute of Industrial Science, The University of Tokyo
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
24.05.2018 | Ecology, The Environment and Conservation
24.05.2018 | Medical Engineering
24.05.2018 | Physics and Astronomy