The research team found clues to the possible extraterrestrial origin of peptides

Dr. Serge Krasnokutski studies the formation of biomolecules at low temperatures in vacuum. Credit: Jens Meyer / University of Jena

Researchers at Friedrichschiller University Jena and Max Planck Institute for Astronomy have shown that peptides can form on dust under conditions such as those common in outer space. I found a new clue to explore. Therefore, these molecules, one of the basic components of all life, may not occur at all on our planet, but may occur in the molecular clouds of the universe. I have.

Amino acid chain

Every life we ​​know is made up of the same thing Chemical building block..These include: peptide, Performs a variety of completely different functions within the body. It transports substances, accelerates reactions, and forms a stabilizing scaffold in cells.Peptides are made up of individual things amino acid They are arranged in a specific order. The exact order determines the final properties of the peptide.

How these versatile biomolecules were born is Origin of life.. For example, the amino acids, nucleobases, and various sugars found in meteoroids indicate that this origin may be an extraterrestrial.However, in order for the peptide to be formed from individual amino acids acid Molecules require very special conditions that were previously assumed to be likely to exist on Earth.

The first step requires water, but the second step should not have water

“Water plays an important role in the traditional way peptides are produced,” says Dr. Serge Krasnoktsky of the Laboratory Astrophysics and Cluster Physics Group at the Max Planck Institute for Astronomy at the University of Jena. .. In this process, the individual amino acids combine to form a chain.One for this to happen water Molecules need to be removed every time. “Our quantum chemistry calculations show that the amino acid glycine can be formed by a combination of a chemical precursor called aminoketen and a water molecule. Simply put, in this case, water is added in the first reaction step. You need to get rid of the water for a while. “

This knowledge allowed the team, led by physicist Krasnoktsky, to demonstrate a reaction pathway that does not require water under cosmic conditions.

“Instead of taking a chemical detour to form amino acids, we wanted to find out if aminoketen molecules were formed and bind them directly to form peptides,” Krasnokutski said. explain. He adds: “And we did this under conditions that spread over the molecular clouds of the universe. Dust particles Abundant corresponding chemicals in vacuum: carbon, ammonia, carbon monoxide. “

and Ultra high vacuum chamberThe substrate, which acts as a model for the surface of dust particles, was collected with carbon, ammonia, and carbon monoxide at about one trillionth of normal atmospheric pressure, minus 263 degrees Celsius.

“Investigations have shown that under these conditions, peptide polyglycine was formed from simple chemicals,” says Krasnokutski. “Therefore, these are very simple chains of the amino acid glycine, and we observed different lengths. The longest specimen consisted of 11 units of amino acid.”

In this experiment, the German team was also able to detect the suspicious aminoketen. “The reaction occurs at such low temperatures because the aminoketen molecules are so reactive that they bind to each other for effective polymerization. The product is polyglycine.”

Quantum mechanical tunneling effect may play a role

“Nevertheless, it was surprising to us that the polymerization of aminoketen could occur very easily under such conditions,” says Krasnokutski. “This is because we need to overcome the energy barriers to actually achieve this. However, special effects of quantum mechanics may have helped this. In this special reaction step, hydrogen. Atoms change their location, but as quantum particles, they couldn’t overcome the barrier because it’s so small, but they could overcome it, so to speak, through the tunneling effect. “

Now that it has become clear that not only amino acids but also peptide chains can be produced under the conditions of the universe, it may be necessary to look not only at the earth but also at the universe when studying the origin of life.

Insights on the origin of life: peptides can be formed without amino acids

For more information:
Sergiy Krasnokutski, Path to Cosmic Peptides by Condensation of Atomic Carbon, Nature Astronomy (2022). DOI: 10.1038 / s41550-021-01577-9..

Quote: The research team found the possibility of extraterrestrial origin of the peptide obtained on February 10, 2022 from https: // (2022). I found a clue (February 10th)

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The research team found clues to the possible extraterrestrial origin of peptides

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