1. Untemplated Nonenzymatic Polymerization of 3′,5′cGMP:A Plausible Route to 3′,5′-Linked Oligonucleotides inPrimordia.
- Author
-
Šponer, Judit E., Šponer, Jiří, Giorgi, Alessandra, Di Mauro, Ernesto, Pino, Samanta, and Costanzo, Giovanna
- Subjects
- *
POLYMERIZATION , *OLIGONUCLEOTIDES , *PHOSPHORYLATION , *CYCLIC compounds , *CHEMICAL reactions - Abstract
The high-energy 3′,5′phosphodiester linkages conservedin 3′,5′ cyclic GMPs offer a genuine solution for monomeractivation required by the transphosphorylation reactions that couldlead to the emergence of the first simple oligonucleotide sequenceson the early Earth. In this work we provide an in-depth characterizationof the effect of the reaction conditions on the yield of the polymerizationreaction of 3′,5′ cyclic GMPs both in aqueous environmentas well as under dehydrating conditions. We show that the thresholdtemperature of the polymerization is about 30 °C lower underdehydrating conditions than in solution. In addition, we present aplausible exergonic reaction pathway for the polymerization reaction,which involves transient formation of anionic centers at the O3′positions of the participating riboses. We suggest that excess Na+cations inhibit the polymerization reaction because theyblock the anionic mechanism via neutralizing the negatively chargedO3′. Our experimental findings are compatible with a prebioticscenario, where gradual desiccation of the environment could inducepolymerization of 3′,5′ cyclic GMPs synthesized in liquid. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF