Back in 1990, a meteorite known as Acfer 086 was found in Algeria. The piece of space matter was preserved for scientific analysis, and now in light of new advanced technologies, a team of researchers from Harvard University and the biotech companies Bruker Scientific and PLEX Corporation took samples of it into the lab for investigation.
Astronomer and chemist Chenoa Tremblay of CSIRO Astronomy & Space Science in Australia, who was not involved in the research, told ScienceAlert:
In general, they’re taking a meteor that has been preserved by a museum and has been analyzed previously. And they are modifying the techniques that they’re using in order to be able to detect amino acid inside of this meteor, but in a higher signal ratio.
Using new analysis techniques (“state-of-the-art” mass spectrometry), they found the first extraterrestrial protein ever identified. It is a previously-unknown protein that they believe didn’t originate here on Earth because its building blocks differ chemically from terrestrial proteins.
The researchers write in a paper uploaded to the preprint server arXiv:
This paper characterizes the first protein to be discovered in a meteorite…this is the first report of a protein from any extra-terrestrial source.
Their work has yet to be peer-reviewed. However, the finding is noteworthy, nonetheless. If the results can be replicated, it will confirm that the protein they found on Acfer 086 is the first one ever seen that is not of this world.
They named the new protein hemolithin. It contains lithium and iron, and like all other proteins, it is an organic molecule made up of building blocks called amino acids. Hemolithin is made up of mostly the amino acid glycine capped with iron, oxygen, and lithium atoms at its ends. All these elements are known and present here on Earth, but the particular arrangement seen here is completely new. Hemolithin may play an important role in seeding life on habitable planets like Earth.
Proteins are a high-energy fuel source and make up most of the machinery within biological cells. There is a theory that life’s building blocks began stacking in space then were delivered to Earth (or any other planet) through impacts by space rocks. Hemolithin is another piece of evidence to justify this case.
Other evidence includes amino acids (or amino acid-like molecules) and other molecules essential to biological life (such as amino acid precursors, cyanide, organic materials, and sugars like ribose, which is found in RNA) located in space – on asteroids and comets. Many molecules that are vital for life have been detected in meteorites as well.
Tremblay said:
So, we’re pretty sure that proteins are likely to exist in space. But if we can actually start finding evidence of their existence, and what some of the structures and the common structures might be, I think that’s really interesting and exciting.
However, finding amino acids floating around is not the same as seeing them arranged in a structure as complex as a protein. The scientists are still speculating as to how hemolitin could have formed in space. Although, individual units of glycine have been predicted to develop on the surface of dust grains. If so, warm molecular clouds could have created the ideal conditions for these units to start linking up into polymer chains, and then eventually into proteins.
Hemolitin could give clues to how life started on Earth and how it could start on other planets. The arrangement of atoms at the tips of the protein forms a type of iron oxide – one that has been known to absorb photons of light and split water into hydrogen and oxygen.
Julie McGeoch, corresponding author of the study, told New Atlas:
It is a good candidate molecule to split water thereby allowing it to represent a first energy source to chemistry, going on to biochemistry on the surface of planets like Earth in terms of their mass and distance from their sun. This could apply to planets throughout the Universe.
This finding is not proof that extraterrestrial living creatures exist, but it points in that direction because life can’t manifest without proteins, as far as we know.
