Proteins are responsible for nearly every essential process of life. Their form and structure are of crucial importance for their functionality.
Scientists at the Max Planck Institute of Biochemistry (MPIB) have recently discovered a so far unknown sequence of reactions which is necessary for newly generated proteins to acquire their correct structure.
„In the mechanism we found, the folding is accomplished in a number of fast intermediate steps rather than in one single block“, explains Manajit Hayer-Hartl, MPIB research group leader. „Because this mode of action is energetically more favorable, the proteins are folded not only correctly, but also much faster than previously assumed.“
Proteins are the workhorses of the cell and thus responsible for almost all biological functions including metabolism, signal transmission or the determination of the cell’s shape. However, before they can fulfill their various tasks, the chain-like molecules must first adopt an intricate three-dimensional conformation. This process is called protein folding and is one of the most important processes in biology.
In fact, in the event of improper folding, proteins are often no more able to carry out their duties, or even tend to clump together in aggregates. This in turn can lead to severe diseases like Alzheimer’s or Parkinson’s. In order to avoid this, specialized proteins, the so-called chaperones, help other proteins to adopt their proper shape.
The bacterial chaperones GroEL and GroES serve as an example for this principle: together, they build up a cage-like structure in which they encapsulate new, not yet folded proteins, thereby al-lowing them to fold properly. However, the exact way in which this is accomplished has so far been unclear and is a research topic of the MPIB team led by Manajit Hayer-Hartl and F. Ulrich Hartl, in collaboration with John Engen from Northeastern University in Boston.
Active acceleration of folding
„Our results demonstrate that the chaperones not only prevent protein clumping, but also dramatically accelerate the folding process”, explains Florian Georgescauld, scientist at the MPIB. „Surprisingly, the chaperones achieve this by changing the mechanism of folding: Instead of folding in one large single block, the protein gets its final structure in a series of small, rapid steps – like an elaborate high-speed Origami.” The researchers think that splitting up the reaction might render it energetically more favorable, which in turn would lead to increased speed. Hence, the folding process is finished in a few seconds rather than in several minutes.
The study shows for the first time that chaperones can act not only passively, by preventing aggregation, but as an active folding cage that catalyzes the folding process. This results in a high-speed folding mechanism which is of particular biological relevance, so the researchers say, since in this way proteins can be folded faster than they are produced. Thus, a backlog of proteins which are not yet or improperly folded and the disastrous consequences which might go along with this can be avoided.
F. Georgescauld, K. Popova, A. J. Gupta, A. Bracher, J. R. Engen, M. Hayer-Hartl and F. U. Hartl: GroEL/ES Chaperonin Modulates the Mechanism and Accelerates the Rate of TIM-Barrel Domain Folding. Cell, May 8, 2014.
Dr. Manajit Hayer-Hartl
Chaperonin-assisted Protein Folding
Max Planck Institute of Biochemistry
Am Klopferspitz 18
http://www.biochem.mpg.de/news/ueber_das_institut/forschungsbereiche/strukturforschung/hayer_hartl_press - Press Page of the Research Group "Chaperonin-assisted Protein Folding" (Manajit Hayer-Hartl)
http://www.biochem.mpg.de/en/rg/hayer-hartl - Website of the Research Group "Chaperonin-assisted Protein Folding" (Manajit Hayer-Hartl)
Anja Konschak | Max-Planck-Institut
Speech dynamics are coded in the left motor cortex
31.03.2015 | Universitätsmedizin Göttingen - Georg-August-Universität
Discovery of two new species of primitive fishes discovered
31.03.2015 | Universität Zürich
In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...
The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.
As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...
When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.
The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe.
Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...
Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.
From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...
25.03.2015 | Event News
19.03.2015 | Event News
17.03.2015 | Event News
31.03.2015 | Life Sciences
31.03.2015 | Life Sciences
31.03.2015 | Life Sciences