Author:
Ter-Ovanessian Louis M. P.,Rigaud Baptiste,Mezzetti Alberto,Lambert Jean-François,Maurel Marie-Christine
Abstract
AbstractThe first step of pyrimidine synthesis along the orotate pathway is studied to test the hypothesis of geochemical continuity of protometabolic pathways at the origins of life. Carbamoyl phosphate (CP) is the first high-energy building block that intervenes in the in vivo synthesis of the uracil ring of UMP. Thus, the likelihood of its occurrence in prebiotic conditions is investigated herein. The evolution of carbamoyl phosphate in water and in ammonia aqueous solutions without enzymes was characterised using ATR-IR, 31P and 13C spectroscopies. Carbamoyl phosphate initially appears stable in water at ambient conditions before transforming to cyanate and carbamate/hydrogenocarbonate species within a matter of hours. Cyanate, less labile than CP, remains a potential carbamoylating agent. In the presence of ammonia, CP decomposition occurs more rapidly and generates urea. We conclude that CP is not a likely prebiotic reagent by itself. Alternatively, cyanate and urea may be more promising substitutes for CP, because they are both “energy-rich” (high free enthalpy molecules in aqueous solutions) and kinetically inert regarding hydrolysis. Energy-rich inorganic molecules such as trimetaphosphate or phosphoramidates were also explored for their suitability as sources of carbamoyl phosphate. Although these species did not generate CP or other carbamoylating agents, they exhibited energy transduction, specifically the formation of high-energy P–N bonds. Future efforts should aim to evaluate the role of carbamoylating agents in aspartate carbamoylation, which is the following reaction in the orotate pathway.
Publisher
Springer Science and Business Media LLC
Reference73 articles.
1. Cleaves, H. J., Butch, C., Burger, P. B., Goodwin, J. & Meringer, M. One among millions: The chemical space of nucleic acid-like molecules. J. Chem. Inf. Model. https://doi.org/10.1021/acs.jcim.9b00632 (2019).
2. Muchowska, K. B., Varma, S. J. & Moran, J. Nonenzymatic metabolic reactions and life’s origins. Chem. Rev. 120, 7708–7744 (2020).
3. Horowitz, N. H. On the evolution of biochemical syntheses. Proc. Natl. Acad. Sci. USA 31, 153–157 (1945).
4. Cairns-Smith, A. G. Seven Clues to the Origin of Life: A Scientific Detective Story (Cambridge University Press, 1990).
5. Cairns-Smith, A. G. The origin of life and the nature of the primitive gene. J. Theor. Biol. 10, 53–88 (1966).
Cited by
9 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献