Protein renaturation
Scientists have come up with a way to "resurrect" proteins
Scientists from ITMO University and the Hebrew University in Jerusalem have come up with a way to restore the structure of proteins after temperature denaturation.
The method is able not only to restore the active function of proteins, but also to increase their initial activity almost twice. Scientists have called this phenomenon the phoenix effect, drawing an analogy with the famous mythical creature, which, resurrecting after death, becomes even stronger. The results of the work are published in the journal Scientific Reports (Vladimir V. Vinogradov & David Avnir, Enzyme renaturation to higher activity driven by the sol-gel transition: Carbonic anhydrase, in open access).
Proteins are one of the most important molecules in the cell. They can perform their functions only if their structure is not broken. When the structure changes, for example, when heated, the protein becomes inactive. This process is called denaturation. Theoretically, proteins can be restored to activity if their original structure is restored – renaturated. But in practice it is extremely difficult to do this.
In their study, scientists from ITMO University and the Hebrew University in Jerusalem showed for the first time that it is possible not only to restore the structure of the renatured protein, but also to increase its activity compared to the native form. This result was achieved thanks to a new method of protein renaturation based on mixing denatured protein molecules (carbon anhydrase) with a colloidal solution of inorganic aluminum oxide nanoparticles.
Scheme of protein renaturation using aluminum oxide particles. Image: ITMO Press Service
During the transition of the colloidal solution to the gel, the nanoparticles begin to cross-link with each other, exerting mechanical pressure on the protein molecules. As a result, each protein molecule gets into an individual porous shell of nanoparticles, which prevents the proteins from tangling and returns them to their original spatial structure.
Comparing the effectiveness of proteins before denaturation and after renaturation, scientists found that the "resurrected" proteins became 180% more effective than their native predecessors. Scientists explain this effect by the fact that nanoparticles "turn out" the active center of the protein so that the substrate with which it interacts can reach it as easily as possible.
As the co-author of the study, David Avnir, explained, the discovery can also be used to optimize the production of drugs based on active proteins: "Most of the most effective drugs today are based precisely on proteins that are obtained from living cells. However, among the proteins produced in this way, only about 20% are native and usable, while the remaining 80% are so–called inclusion bodies - also proteins, but denatured. It is obvious that the possibility of transferring denatured proteins back to the active state, and even with increased efficiency, would make it possible to reduce the cost of production of many drugs and make them more accessible."
In 2015, another team of researchers was awarded the Nobel Prize for a similar work – the restoration of the protein structure of a chicken egg destroyed during thermal denaturation.
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02.10.2015