The question of how life first emerged here on Earth is a mystery that continues to elude scientists. Despite everything that scientists have learned from the fossil record and geological history, it is still not known how organic life emerged from inorganic elements (a process known as abiogenesis) billions of years ago.

One of the more daunting aspects of the mystery has to do with peptides and enzymes, which fall into something of a “chicken and egg” situation.

Addressing this, a team of researchers from the University College London (UCL) recently conducted a study that effectively demonstrated that peptides could have formed in conditions analogus to primordial Earth.

The study which details their findings was recently published in the scientific journal Nature. The research team was led by Dr. Matthew Powner, a Reader of Organic Chemistry with UCL’s Department of Chemistry, and included Pierre Canavelli and Dr. Saidul Islam – both of whom are researchers with UCL’s Organic and Biological Chemistry Section.

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As Powner explained the purpose of their study in a recent interview with UCL News:

“Peptides, which are chains of amino acids, are an absolutely essential element of all life on Earth. They form the fabric of proteins, which serve as catalysts for biological processes, but they themselves require enzymes to control their formation from amino acids. So we’ve had a classic chicken-and-egg problem – how were the first enzymes made?”

As they indicate in their study, considerable research in the past has been dedicated to finding out how peptides first formed and allowed for the emergence of life. However, all previous research has focused on amino acids, rather than the reactivity of their chemical precursors (known as aminonitriles).

Whereas aminonitriles require harsh conditions to form amino acids (typically strongly acidic or alkaline), amino acids need to be recharged with energy to form peptides. However, the researchers found a way to bypass both of these steps by demonstrating that peptides could be made directly from energy-rich aminonitriles.

Their method took advantage of the built-in reactivity of aminonitriles with the other molecules that were a part of Earth’s primordial environment. The process consisted of combining hydrogen sulfide with aminonitriles and the chemical substrate ferricyanide ([Fe(CN)6]3?) in water, which yielded peptides.


The original story, which contains more detail, can be found here: