Drops of water hold the secret ingredient for building life

Chemists at Purdue University have discovered the mechanism behind peptide-forming reactions that occur in water — something that has baffled scientists for decades.

“That’s basically it chemistry behind the origin of life” said Graham Cooks, Henry Bon Haas Distinguished Professor of Analytical Chemistry in the Purdue College of Science. “This is the first demonstration that the primordial molecules, simple amino acids, spontaneously form peptides, the building blocks of life, in droplets of pure water. It’s a dramatic revelation.”

This water chemistry, which leads to proteins and thus to life on Earth, could also lead to faster drug development for humanity’s most debilitating diseases. The team’s findings were published in the journal Proceedings of the National Academy of Sciences.

For decades, scientists have theorized that life on Earth originated in the oceans. The chemistry, however, remained a mystery. Raw amino acids—what meteorites delivered daily to the early Earth—can react and bond together to form peptides, the building blocks of proteins and, eventually, life. Surprisingly, this process requires the loss of a water molecule, which seems highly unlikely in a humid, aquatic, or oceanic environment. Water was needed for the origin of life. But he also needed a place away from the water.

Kukharov, connoisseur of mass spectrometry and early Earth chemistry, and his team discovered the answer to the riddle: “Water is not wet everywhere.” In fields where a drop of water meets the atmosphere, incredibly fast reactions can occur that turn abiotic amino acids into the building blocks of life. Places where sea spray flies into the air and waves hit the ground, or where fresh water bubbles down the slope, were fertile landscapes for the potential evolution of life.

Chemists spent more than 10 years on its use mass spectrometers to learn chemical reactions in drops containing water.

“The rate of reactions in droplets is a hundred to a million times faster than the same chemicals reacting in bulk solution,” Cooks said.

The rates of these reactions make catalysts unnecessary, speeding up reactions and, in the case of early Earth chemistry, making the evolution of life possible. Understanding how this process works has been the goal of decades of scientific research. The secret of how life originated on Earth could help scientists understand why it happened and provide a reason to search for life on other planets and even moons.

Understanding how amino acids are built into proteins and eventually into life forms is revolutionizing scientists’ understanding of chemical synthesis. That same chemistry can now help synthetic chemists speed up reactions critical to the discovery and development of new drugs and therapeutics for disease.

“If you walk around campus at night, there are synthetic chemists working in buildings with lights on,” Cooks said. “Their experiments are so slow that they take days or weeks. That’s optional, and we’ve created an apparatus that’s now being used at Purdue to speed up the synthesis of new chemicals using droplet chemistry. and potential new drugs.”