Prebiotic syntheses of vitamin coenzymes: I. Cysteamine and 2-mercaptoethanesulfonic acid (coenzyme M)

Abstract

The reaction of NH 3 and SO 2-with ethylene sulfide is shown to be a prebiotic synthesis of cysteamine and 2-mercaptoethanesulfonic acid (coenzyme M). A similar reaction with ethylene imine would give cysteamine and taurine. Ethylene oxide would react with NH3 and N(CH3) 3 to give the phospholipid components ethanolamine and choline. The prebiotic sources of ethylene sulfide, ethylene imine and ethylene oxide are discussed. Cysteamine itself is not a suitable thioester for metabolic processes because of acyl transfer to the amino group, but this can be prevented by using an amide of cysteamine. The use of cysteamine in coenzyme A may have been due to its prebiotic abundance. The facile prebiotic synthesis of both cysteamine and coenzyme M suggests that they were involved in very early metabolic pathways.There has been little work on the prebiotic synthesis of vitamin coenzymes with the exception of the nicotinic acid synthesis from cyanoacetaldehyde and propiolaldehyde (Dowler et al. 1970) and from hydrocarbons and NH3 directly in a spark discharge (Friedmann et al. 1971). Eschenmoser (1988 has shown that a number of the steps in the chemical synthesis of vitamin B]2 proceed easily, although the conditions cannot be considered prebiotic.Offprint requests to: S.L. MillerThe utilization of coenzyme A in the metabolism of most organisms, including several methanogens (Leigh 1983), suggests that it appeared very early in biochemical evolution. The prebiotic formation of thiol esters from ketoaldehydes (Weber, 1981) and the importance of acetate activation suggest that coenzyme A and its precursors may have been important in NH2 O=P-O" O OH I

Structural insights into the evolution of the pantothenate-biosynthesis pathway

“…The possible chemical compositions of the prebiotic soup and early atmosphere are the subject of some debate, but the potential availability of pantothenate and its precursors has been shown experimentally [9].…”

Vanin-1–/– mice show decreased NSAID- and Schistosoma-induced intestinal inflammation associated with higher glutathione stores

“…Cysteamine is a low-molecular thiol broadly distributed in organisms, from Drosophila to humans. This wide distribution and the mechanisms involving low-molecular thiols are likely to reflect the early steps of molecular evolution (8). In vivo, cysteamine is in equilibrium with its oxidized form cystamine at concentrations of approximately 20 µM (9)(10)(11)(12).…”

Species-Specific Thiol–Disulfide Equilibrium Constant: A Tool To Characterize Redox Transitions of Biological Importance

“…C: The correlation between speciesspecific redox equilibrium constants (logk 3 xY ) and the difference between species-specific thiolate protonation constants of the involved RSH and GSH microspecies (∆logk). The ∆logk values were calculated from the species-specific protonation constants previsously determined[12][13] .The microscopic redox equilibrium constants were calculated from the conditional equilibrium constants using analogous equations as equation(10). Obviously, the conditional equilibrium constants were measured at different pH media, all of which theoretically afford the same value for a certain microscopic equilibrium constant.…”