MOSCOW, October 31, Vladislav Strekopytov. Biochemists from Denmark and the USA have obtained stable DNA-peptide nanostructures, from which they plan to assemble artificial microorganisms in the future. Their main purpose is to protect people from dangerous viruses. About achievements in this area — in the material.
On the way to creating artificial organisms
Decoding the structure of DNA in the middle of the last century became one of the turning points in the history of biology. After this, scientists focused their efforts on developing methods for DNA modification and editing. Today, analogues of complex biomolecules are created in laboratories, which are used, among other things, for the diagnosis and treatment of diseases.
A completely new direction in science associated with artificial life is also actively developing. We are, of course, not talking about laboratory monsters from science fiction films, but about the chemical synthesis of DNA molecules and the assembly of cellular nanostructures from them, and in the future — entire designer organisms. One of the possible applications is the production of “live” antiviruses.
Medicines of the future
Nature is designed in such a way that almost every organism has natural enemies. This allows you to maintain species balance in ecosystems. The exception is some viruses. Without encountering any obstacles, they periodically begin to multiply uncontrollably, causing epidemics. To prevent this, scientists propose creating artificial organisms hostile to viruses.
Perhaps one day, instead of swallowing drugs for every infection, the body will be injected with an adaptable «live» antivirus that will eliminate pathogens on its own or in cooperation with the immune system.
Scientists believe that structures assembled from complex biomolecules could also act as nanorobots for targeted delivery of drugs or markers in medical research, diagnosis, treatment of cancer and other dangerous diseases.
New generation of nanotechnology
Experts believe that the first “live” vaccines will appear in ten years. The immediate task is to create structures with a certain set of cell functions, but from synthesized components.
The first step has already been taken. Last year, scientists led by Chengguan Lu, assistant professor of physics, chemistry and pharmacy at the University of Southern Denmark, and professor Hanbin Mao from Kent State University in Ohio, reported the preparation of a complex organic compound. They describe their supermolecule as a conjugate (fusion) of DNA and peptides — chains of amino acids that make up proteins.
“Combining these two types of substances has provided a powerful molecular tool that belongs to a new generation of nanotechnology,” the press release quotes as saying Dr. Lu.
According to the researchers, these hybrid compounds are quite capable of serving as building blocks for more advanced nanostructures.
Connecting left and right
It is believed that a process involving nucleic acids (the building blocks of DNA) and peptides (chains of amino acids) led to the formation of the first living cell on Earth. These two groups of biomolecules still control almost all biochemical reactions. Together they form the basis of the so-called protein factories.
To control intracellular processes, scientists are developing technologies for modifying biomolecules. When programming DNA, they usually operate on four main elements — nucleotides A, C, G and T. Peptide technology is more flexible, as it allows you to work with 20 amino acids. Combining these two tools has been a long-standing dream of researchers.
However, obtaining such supermolecules, capable of simultaneously carrying genetic information and acting as proteins in cells, has not been possible for a long time due to the problem of chirality. All DNA molecules are right-handed, but peptides are left-handed, so they do not combine in nature.
And now, for the first time, a right-handed peptide has been synthesized in the laboratory, showing that after a change in chirality, peptides can interact with DNA, forming hybrids that are superior in the range of biochemical functions to any natural analogues.
Supermolecules
's superpowersThere are great hopes for hybrid supermolecules. Tiny biobots assembled from conjugates can be coded to solve a variety of specific medical problems, including targeted drug delivery or stimulation of the immune system. But first of all, these are potential “live” vaccines that can cope with the most terrible viruses, since DNA-peptide nanoassemblies adapt both to specific pathogens and to the individual characteristics of the body.
It is also possible to create artificial proteins, more resistant than natural ones to heat, ultraviolet radiation and chemical reagents, and therefore more stable. It is possible that such compounds will serve as the basis for a new generation of drugs for the treatment of many serious diseases, in particular Alzheimer's disease, which is caused by disturbances in the structure of certain proteins.
“This will be a revolution in medicine,” concludes Chengguan Lu.
September 28, 08:00
Bricks of artificial life
Hybrid bionanomaterials are being developed in different countries. British scientists from the University of Oxford, for example, have developed a DNA-peptide nanobot that penetrates the cell membrane, creating an artificial channel for the delivery of drugs and diagnostic markers.
Biochemists from Arizona State University in the USA, having linked modified peptides and DNA, chain biomolecular 3D structures of micrometer length were obtained. And they demonstrated that the self-assembly mode of such compounds can be programmed.
Researchers from Northwestern University in Illinois have created artificial materials with similar properties by placing DNA strands in a peptide hydrogel, which is used as an extracellular matrix simulator for cultured cell cultures. After adding DNA strands, the colloidal solution micelles self-assembled into hierarchical biofiber structures. The most surprising thing is that the process turned out to be reversible.
And Israeli scientists from Ben-Gurion University found that with an increase in the concentration of nucleic acids in a peptide solution, fibrous nanostructures are replaced by stable spherical conjugates, which are even more suitable for the role of building blocks of artificial life.