Previous studies on the polymerization of 3’,5’ cyclic guanosine monophosphate (cGMP) demonstrated the potential of the compound in the abiotic generation of the first oligonucleotide sequences on the early Earth. These experiments were conducted under idealized laboratory conditions that logically raises the question whether the same chemistry could take place in the harsh environment present on our planet in its earliest days. In my talk I will focus on the mineralogical context of this chemistry.
Our recent results (1) show that numerous, but not all, common minerals assumed to be present on the early Earth could host the polymerization of H-form 3’,5’ cGMP. In particular, we have found that quartz varieties are especially suitable for the purpose, similar to andalusite, amphibole or micas. On the contrary, olivine, calcite, and serpentine-group minerals interfere with the studied polymerization chemistry. Our results show that crystallization on mineral surfaces, that is mainly a diffusion controlled process, determines the ability of 3’,5’ cGMP to polymerize. The observation that numerous amorphous and crystalline SiO2 forms are compatible with the oligomerization chemistry suggests that the process could commonly occur in a wide range of primordial environments allowing for crystallization of the cyclic monomers from a dropping solution.
1. Šponer, J. E.; Šponer, J.; Výravský, J.; Šedo, O.; Zdráhal, Z.; Costanzo, G.; Di Mauro, E.; Wunnava, S.; Braun, D.; Matyášek, R.; Kovařík, A., Non-enzymatic, template-free polymerization of 3’,5’ cyclic guanosine monophosphate on mineral surfaces. ChemSystemsChem, in press, DOI:10.1002/syst.202100017.