NEW BRUNSWICK — A team of Rutgers University researchers has modeled a simple protein that could help explain the start of life on Earth.
They used computer models to design a primitive protein that could have spontaneously arisen in early oceans and that has characteristics needed to help cells metabolize, according to study co-author Vikas Nanda, an associate professor at Rutgers’ Robert Wood Johnson Medical School.
Their study of a primordial peptide, or short protein, was published recently in the Journal of the American Chemical Society.
Senior author Professor Paul G. Falkowski, who leads Rutgers’ Environmental Biophysics and Molecular Ecology Laboratory, recently won the 2018 Tyler Prize for Environmental Achievement for his work on the evolution of climate.
Human DNA codes for complex proteins are a few hundred to a few thousand amino acids long.
They allow all living things to function properly and are the result of billions of years of evolution.
But scientists have speculated that proteins were simpler and shorter — perhaps just 10 to 20 amino acids long — when life began.
With computer modeling, a Rutgers team designed a short, 12-amino acid protein and tested it in the laboratory.
It contains only two types of amino acids, is very short and could have emerged spontaneously on the early Earth in the right conditions, the team reported.
The metal cluster at its core resembles iron-sulfur minerals abundant in early Earth oceans. The peptide also can charge and discharge electrons repeatedly without falling apart, Nanda said.
“Modern proteins called ferredoxins do this, shuttling electrons around the cell to promote metabolism,” Falkowski said. “A primordial peptide like the one we studied may have served a similar function in the origins of life.”
Chemist Günter Wächtershäuser postulated decades ago that life began on iron- and sulfur-containing rocks in the ocean, the Rutgers team said. He and others predicted short peptides would have bound metals and served as catalysts of life-producing chemistry.