Recreating prehistoric enzymes.

Recreating prehistoric enzymes

Cyril Ponnamperuma has spent much of the past 30 years stewing methane, nitrogen, water -- and, most recently, a pinch of minerals -- into primordial soups and sampling each batch for signs of life's chemical building blocks: the amino acids that make up proteins. While stalking the elusive recipe for creating life on Earth, he and others have demonstrated that "almost all the 20 [most common] amino acids can be produced -- either directly or in a step-wise manner" -- from these soups, says Ponnamperuma, who directs the Laboratory of Chemical Evolution at the University of Maryland in College Park. His latest efforts appear to have yielded a functionally new ingredient: a simple molecule, consisting of five or six amino acids, "that behaves like an enzyme," he says.

Alone and when bound to zinc or copper, this molecute appears to hasten the rate at which the protein cytochrome-C donates electrons to oxygen, Ponnamperuma reports. Cytochrome-C assists in electron transport during respiration and photosynthesis. Ponnamperuma is now screening his soups for evidence of a potentially more important enzyme: a polymerase, which combines small molecules into a long chain.