Abiotic Phosphorylation Reactions in the Origin of Life

Or Cohen^a, Meital Reches^a,b, Moran Frenkel-Pinter^a,b

^aInstitute of Chemistry, The Hebrew University of Jerusalem, Israel 9190401

^bThe Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Israel 9190401

In current biology, phosphorylation reactions are catalyzed by phosphotransferases and are dependent on the essential supply of inorganic orthophosphate as a fundamental source of phosphorus. Nevertheless, before the emergence of highly evolved enzymes through a prolonged process of chemical evolution, alternative simpler molecules could have been involved in the proto-metabolism of phosphorus. These prebiotic molecules could have acted as phosphate carriers in a proto-metabolic system or as intermediates in the synthesis of phosphate-containing end products. Trimetaphosphate (TMP), a cyclic condensed phosphate that can be produced under volcanic conditions, is a versatile phosphorylating agent of various functional groups, even in the aqueous environment. In the presented study we investigate the potential prebiotic synthesis of simple phosphorylated molecules and their potential role in the origin of life (OoL) in the presence of TMP as an activated phosphorus source. In particular, we investigate N,O-diphosphoserine (N,O-dpSer) as a model of a  bis-phosphorylated species containing both phosphate and amidophosphate moieties. As another model system, we investigate the reaction between TMP and different thiol-containing molecules as a route for the formation of direct P-S (thiophosphate) bonds. So far, using ¹H- and ³¹P-NMR spectroscopy, we were able to demonstrate N-phosphorylation and S-phosphorylation of O-phospho-L-serine and thioglycolic acid, respectively, in the presence of TMP under alkaline conditions. Our results imply that in a system containing TMP in the presence of very simple and prebiotic plausible molecules, such as amino acids and mercapto acids, intriguing phosphorylated species that could play a role in the proto-metabolism of phosphorus are formed.