Transition Metal Catalysts Could Be Key to Origin of Life, Scientists Report

[Elmore Furth]

Here is an interesting hypothesis about how metabolism may have transitioned from inorganic to organic mechanisms.

ScienceDaily (Sep. 3, 2010) — One of the big, unsolved problems in explaining how life arose on Earth is a chicken-and-egg paradox: How could the basic biochemicals -- such as amino acids and nucleotides -- have arisen before the biological catalysts (proteins or ribozymes) existed to carry out their formation?

In a paper appearing in the current issue of The Biological Bulletin, scientists propose that a third type of catalyst could have jumpstarted metabolism and life itself, deep in hydrothermal ocean vents.

According to the scientists' model, which is experimentally testable, molecular structures involving transition metal elements (iron, copper, nickel, etc.) and ligands (small organic molecules) could have catalyzed the synthesis of basic biochemicals (monomers) that acted as building blocks for more complex molecules, leading ultimately to the origin of life. The model has been put forth by Harold Morowitz of George Mason University (GMU), Vijayasarathy Srinivasan of GMU, and Eric Smith of the Santa Fe Institute.

"We think life probably began with the reductive citric acid cycle, and there is evidence that under hydrothermal vent conditions some of the cycle's intermediates form," Morowitz says. "We are going to start with these molecules and mix them with various transition metals, cook them at different temperatures for a while, and see what kinds of catalysts we've made."


Transition Metal Catalysts Could Be Key to Origin of Life, Scientists Report