We construct protein complexes with atom precision
The program will help to assemble a "protein constructor"
<url>Scientists have created a technology for computer-aided design of protein complexes de novo.
It will make it possible to create artificial structures from polypeptides with pre-calculated properties. The work was published in the journal Science (King et al., Computational Design of Self-Assembling Protein Nanomaterials with Atomic Level Accuracy).
The work consists of several stages. First, the researchers choose the type of symmetry of the desired complex. Then, in accordance with it, a polypeptide is selected, which will become the "building block" of the future structure. They can be different proteins that do not necessarily form complexes in nature. The only limitation is that the structure of proteins must contain symmetry elements corresponding to the symmetry of the complex.
At the next stage, the initial structure is assembled, the elements of which are then carefully adjusted to each other. At the final stage, scientists insert into the sequence of polypeptides such amino acids that will form bonds between the contacting surfaces.
As an illustration of the possibility of the developed technology, the authors created two complexes with sizes of 13 and 11 nanometers. One of them had octahedral symmetry and contained 24 subunits, and the other had tetrahedral symmetry and included 11 subunits.
Scientists cloned the genes of the developed proteins, introduced them into recombinant microorganisms, obtained complexes and established their structure by X-ray diffraction analysis. The position of the atoms in the complexes practically did not differ from that predicted by the program.
The scheme of creating a protein "constructor".
First, the type of symmetry is selected, then the working block,
assembly, fitting and finally the design of the interconnections are carried out.
Image from an article by King et al.
Earlier, the same group of scientists was able to rationally change the structure of two proteins so that they bind to the surface of the influenza virus.
The developed technology is important for understanding the relationship between the amino acid sequence of a protein and its structure. In addition, it is an alternative to the creation of complexes from nucleic acids using the DNA origami method (or the assembly of complexes from short oligonucleotides). Researchers hope to use similar structures to create molecular nanorobots. Structures made of proteins may be more practical than those made of DNA, since peptides have a wide variety of chemical properties and potentially should be more resistant to adverse external conditions.
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