Poles have built a protein cage with an “impossible” geometry

An international team of researchers, including scientists from the Jagiellonian University, has created a protein cage – a nanoscale structure that can be used to deliver drugs to specific sites in the body. Interestingly, the geometry of the cage appears to defy the laws of mathematics.

The 22-nanometer diameter structure created by the researchersow is extremely durable – Can withstand being boiled in water for several hours and is resistant to acidow and principles. In addition, it can be easily assembled and disassembled.

Scientists hope that in such cages it will be possible to deliver to the comorek needed substances and release them under controlled conditions. Inside a protein cage – about the size of a virus – extraordinary treasures can be locked up. They accommodate up to a few dozen molecules of proteins, nucleic acids or e.g. drugs.

The results of the press were presented in the journal „Nature”.

Scientists are interested in making artificial protein cages in hopes of imparting useful and novel properties to them. Achieving this goal presents two challenges. The first is a problem with geometry – someore proteins may have great utility, but are automatically excluded because they are the wrong shape for cage assembly. The second problem is complexity – most protein-protein interactions are mediated by complex networks of weak chemical bonds, whichore are very difficult to design from scratch.

The research began at the Heddle Initiative Research Unit in RIKEN, Japan, and has been transferred to the Small Biotechnology Center at Jagiellonian University. Scientists have found a wayob for solving both problemsow.

Just making an artificial protein is an art. But that’s not all the international team managed to show. It turns out that the protein subunits that make up this structure are not glued or tangled together, as is usually the case in proteins. They are linked together very elegantly – only through bonds with ionoin Gold. This makes it easier to produce structures with controlled shapes from such proteins.

– We were able to replace complex interactions between proteins with simple ones „staples” based on single gold atoms – explained research leader Professor Jonathan Heddle. – This simplifies the design problem and allows us to imbue the cages with new properties – added.

Researchers have found row wayob to circumvent the geometric problem. – The components of our protein cage are 11-angled rings, said Ali Malay, first author of the paper from the RIKEN Center for Sustainable Resource Science. The researcher added that for the mathematicianoin such a facility may seem impossible to perform.

– The geometry of this cage defies the laws of mathematics – stated in an interview with the Polish Press Agency wsporoject author Dr. Artur Biela of the Jagiellonian University. He also explained that the protein cage consists of 24 identical 11-angle protein rings connected by gold ions.

A mathematician would say that the kind of 24-wall that the scientists presented can and can be assembled from 24 pentagonsow, but not from the 11-angles themselvesow. 11-angles because they are not figures, whichore enough to build a polyhedral. But what is not possible in the rigid world of mathematics is, it turns out, possible in the world of flexible proteins.

Scientists have discovered that due to their natural flexibility, protein complexes can achieve unprecedented structures based on near-perfect geometric convergence. The elasticity of proteins makes it easy to cover up the small irregularities that occur in the solid. – Now we can consider using proteins thatore were previously ignored due to „bad” shape – admitted Malay.

Designed by the teamoĊ‚ protein „golden cage” consists of 264 identical proteins (TRAPs) pinned together in 11-angle rings. 24 such rings connect 120 gold „staples” – single ionoin gold. In further research, scientists want to modify their protein "golden frames" so as to give them further desired properties. E.g. such, whichore will safely lead such a protein casket to the desired place in the body and open it at the right moment.