[M-IS02] Astrobiology

[MIS02-04] Thioesters as primordial energy currency: kinetics, thermodynamics, their use by enzymes during evolution

*Shawn E McGlynn^1,2, Liam M Longo^1,2, Sebastian A Sanden¹, Ruiqin Yi¹ (1.Tokyo Institute of Technology, 2.Blue Marble Space Institute of Science)

Keywords:Energy Exchange Reactions, Protein Evolution, Thioesters, Phosphoesters, Iron-sulfur redox

A centerpiece of biological chemistry is the buildup of a hydrolysable disequilibrium that can be used to overcome kinetic and thermodynamic energy barriers. While nucleotide triphosphates are the primary hydrolysable agent in life today, other molecules may have been used in primordial metabolism. In this work, we present data from computational chemistry, laboratory chemistry, and protein evolution studies to shed light on the possibility that thioesters predate phosphoesters in metabolism. Differences in the kinetic and thermodynamic properties of these molecular types may have led to the early adoption or exclusion of one type. Following the emergence of a protein world, the metabolic placement and protein fold recruitment of thioesters and phosphoesters provides insight into the evolutionary select-ability of these molecules. Finally, we present laboratory results demonstrating a new synthetic route to thioesters, which connects to amino acid, peptide, and iron-sulfur cluster biosynthesis.