This leads to cataract formation, the world’s leading cause of blindness. This work could shed light on other protein aggregation diseases (such as Alzheimer’s disease), and may one day lead to methods for stabilizing protein interactions and thus preventing these problematic aggregations from occurring.
The eye lens is made up of densely packed crystallin proteins, arranged in such a way that light in the visible wavelength range can pass through. But for a variety of reasons including UV radiation exposure and age, the proteins sometimes change their behavior and clump together. As a result, light is scattered once it enters the lens, resulting in cloudy vision or blindness. There is currently no known way to reverse the protein aggregation process once it has begun. Nearly 5 million people every year undergo cataract surgery in which their lenses are removed and replaced with artificial ones.
Previous research has shown that the interactions between the three major crystallin proteins that make up the concentrated eye lens protein solution are key to cataract formation. A team of scientists from the University of Fribourg, EPFL and the Rochester Institute of Technology (USA) studied the interactions between two of these proteins, at concentrations similar to those found in the eye lens, using a combination of neutron scattering experiments and molecular dynamics computer simulations. They found that a finely tuned combination of attraction and repulsion between the two proteins resulted in an arrangement that was transparent to visible light. “By combining experiments and simulations it became possible to quantify that there had to be a weak attraction between the proteins in order for the eye lens to be transparent,” explains EPFL postdoctoral researcher Giuseppe Foffi, a member of the Institut Romand de Recherche Numerique en Physique des Materiaux (IRRMA). “Our results indicate that cataracts may form if this balance of attractions is disrupted, and this opens a new direction for research into cataract formation.”
“Lots of studies have been done on individual proteins in the lens,” adds University of Fribourg physicist and lead author Anna Stradner, “But none on their mixtures at concentrations typically found in the eye. We modeled these proteins as colloidal particles, and found there was a very narrow window in which the protein solution remained stable, and this was a necessary condition for lens transparency.”
In addition to unveiling important new information about the interactions of the proteins in the eye lens, this benchmark study provides a framework for further study into the molecular properties and interactions of proteins. The results suggest that these properties could perhaps be manipulated to prevent aggregation or reverse the aggregation process once it has begun.
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22.09.2017 | University of Kansas
22.09.2017 | Forschungszentrum MATHEON ECMath
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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