At some point in history of Earths, there was a critical point where chemical reactions between organic molecules began to form something biological. The first metabolic reaction remains to this day an area of speculation, however a group of researchers from the Rutgers University they identified a protein that may have played a key role in the beginning of life as we know it.
Ο λόγος για ένα πεπτίδιο το οποίο αποκαλούν Nickelback. Η ονομασία προήλθε από την “ραχοκοκαλιά” της πρωτεΐνης, η οποία αποτελείται από μία αλυσίδα αμινοξέων και δύο άτομα υδρογόνου τα οποία συνδέονται με ένα ζεύγος ατόμων of nickel.
Scientists believe that sometime between 3.5 and 3.8 billion years ago, there was a tipping point, which started the shift from probiotic chemistry – pre-life molecules – to living, biological systems. We believe that the change was caused by a few proteins that performed key steps in an ancient metabolic reaction. And we think we have found one of these initial peptides. – Vikas Nanda, biochemist and molecular biologist
To arrive at this peptide, scientists started with modern proteins that guide the metabolic processes in many biochemical reactions. Ancient proteins would have been much simpler, so scientists broke proteins down into their basic features. The experiments pointed to Nickelback as a possible candidate that could form on the probiotic Earth, but at the same time is complex enough to draw energy from the environment and produce something with it.
It uses a total of 13 amino acids, the basic components of proteins and practically of life itself. Nickel would have been an abundant metal in the early oceans of our planet. When attached to the peptides, the nickel atoms act as a catalyst and release hydrogen gas, which would have been an important source of energy billions of years ago.
This is very important because there are many theories about the origin of life, but very few laboratory experiments to test these theories. Our work shows that not only are simple protein-metabolizing enzymes possible, but that they are very stable and very active, making them a serious possibility for the origin of life.
This discovery will be useful in knowing which biosignatures to look for when searching for life on other planets.
The research was published in Science Advances.