King's College London

A chemical compound essential to all life has been created in a lab using hydrogen cyanide, in a breakthrough for establishing the origins of life on earth.

In a new study, published in the journal Science, researchers from the Department of Chemistry at King’s College London and UCL synthesised pantetheine, a key component of Coenzyme A (CoA) which is responsible for metabolism.

They did this through cascade reactions in water using molecules derived from hydrogen cyanide, a substance likely abundant on early Earth approximately four billion years ago. By suggesting that hydrogen cyanide could be vital to beginning of life, the team have also widened the parameters of the chemistry that kick-started biology on Earth.

Driven by energy-rich molecules called aminonitriles, the team discovered that individual molecules derived from hydrogen cyanide spontaneously interacted with each other and the water around them that led to the creation of the building blocks of proteins and eventually pantetheine.  

This product was reached through a series of selective and robust chemical pathways, occurring at the same time as several others, and yet avoiding a scenario where the cascade would continue to form irrelevant by-products less pivotal to the origins of life.

The study challenges a view held by some scientists that water is too destructive to molecules necessary for life to originate from, and so it required pools that periodically dried out.

Dr Saidul Islam, Lecturer in Chemistry at King’s College London and co-lead author of the study said, “Water despite being referred to as the ‘solvent of life’ has been seen in some circles to be a poison. It was actually by embracing the ‘water problem’ that pantetheine was created.

“From there, it is likely pantetheine aided chemical reactions that led from the simple predecessors of proteins to the kind of complex life that we now know existed four billion years ago.”

By establishing the creation of pantetheine through simple cascade reactions, the team hope to turn back the clock on how chemistry contributed to complex life at its genesis. As earlier studies failed to synthesise pantetheine effectively, it was believed that it was absent at life’s origin. 

Dr Islam said, “Because pantetheine looks so unusual and complex, it has always been thought that its creation must have come after the advent of complex life, but our work suggests this molecule has always been there, and if so, it certainly would have contributed to the beginning of life on this planet.

“This paper goes to show that just because the structure of a molecule looks complex, it doesn’t mean the chemistry that generated it needs to be as well”.

Early experiments to synthesise pantetheine used so called ‘acid chemistry’, chemistry primarily using acids to create new chemical products, but yields were very low and required extremely high concentrations of chemicals that had been dried out before they were heated to 100 °C.

Nitrile chemistry sidesteps the ‘acid chemistry’ and has the power to yield greater amounts of useful products with lower concentrations of chemicals in water.

As Matthew Powner, Professor of Organic Chemistry at UCL explains, “We struck gold with nitrile chemistry. In school or university, you may have been taught that peptides are made from amino acids, but this is not spontaneous, it requires external energy.

“Through our work, we’ve found that nitrile chemistry provides not only the energy, but also the selectivity required to build these biological molecules in water. This is an important paradigm in understanding the origins of life.”