On the trail of the first extraterrestrial protein, in a meteorite

The first sketch of extraterrestrial protein was discovered in a meteorite that fell on Earth 30 years ago: it is a molecule called hemolyte that probably formed at the origins of the Solar System. If the discovery is confirmed, it would be the first time that "what we think is a protein" is identified on a meteorite, write the authors of the research, coordinated by physicist Malcolm McGeoch, of the American University of Harvard. The article is online on the arXiv website, which collects research that is currently being approved for publication in a scientific journal.

Rich in iron and lithium, the molecule was identified in the Acfer 086 meteorite, found in Algeria in 1990, now analyzed thanks to the new mass spectrometry techniques that allow you to find the footprints of the molecules based on their weight. In the past, basic building blocks of proteins have been discovered on some meteorites, such as some amino acids, or sugars, simple components of hereditary molecules such as Rna, a close relative of DNA. It would be the first discovery of a protein. However, more research is needed for the result to be confirmed.

The same authors of the study do not exclude that it may be a generic polymer, that is, a molecule with multiple chemical groups. Even the opinion of John Brucato, exobiologist of the Arcetri Observatory of the National Institute of Astrophysics (INAF), who considers "premature to speak of protein: it is rather an oligomer, that is, a simple chain of amino acids" is also doubtful.

The aspect on which the authors are more unbalanced, however, is the extraterrestrial origin of the molecule. In fact, they analyzed the relationship between hydrogen and a slightly heavier variant, deuterium, in hemolitin to identify its date of birth. The data indicate that it may have formed "in the disc of gas and dust from which the Solar System was born about 4.6 billion years ago".