title: Catalytic effects of Murchison material: prebiotic synthesis and degradation of RNA precursors.
abstract: Mineral components of the Murchison meteorite were investigated in terms of potential catalytic effects on synthetic and hydrolytic reactions related to ribonucleic acid. We found that the mineral surfaces catalyzed condensation reactions of formamide to form carboxylic acids, amino acids, nucleobases and sugar precursors. These results suggest that formamide condensation reactions in the parent bodies of carbonaceous meteorites could give rise to multiple organic compounds thought to be required for the emergence of life. Previous studies have demonstrated similar catalytic effects for mineral assemblies likely to have been present in the early Earth environment. The minerals had little or no effect in promoting hydrolysis of RNA (24mer of polyadenylic acid) at 80°C over a pH range from 4.2 to 9.3. RNA was most stable in the neutral pH range, with a half-life ~5 h, but at higher and lower pH ranges the half-life decreased to ~1 h. These results suggest that if RNA was somehow incorporated into a primitive form of RNA-based thermophilic life, either it must be protected from random hydrolytic events, or the rate of synthesis must exceed the rate of hydrolysis.
authors.affiliation: Department of Agrobiology and Agrochemistry, University of Tuscia, Viterbo, Italy. saladino@unitus.it
authors.forename: Raffaele
authors.initials: R
authors.lastname: Saladino
authors.forename: Claudia
authors.initials: C
authors.lastname: Crestini
authors.forename: Cristina
authors.initials: C
authors.lastname: Cossetti
authors.forename: Ernesto
authors.initials: E
authors.lastname: Di Mauro
authors.forename: David
authors.initials: D
authors.lastname: Deamer
mesh_terms: D000596:Amino Acids / Q000138:chemical synthesis*; D002244:Carbon / Q000737:chemistry; D002264:Carboxylic Acids / Q000138:chemical synthesis*; D002384:Catalysis; D018534:Earth, Planet; D005559:Formamides; D008401:Gas Chromatography-Mass Spectrometry; D006207:Half-Life; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D019110:Meteoroids; D011687:Purines / Q000138:chemical synthesis*; D011743:Pyrimidines / Q000138:chemical synthesis*; D012313:RNA / Q000032:analysis / Q000737:chemistry*; D020871:RNA Stability; D014867:Water / Q000737:chemistry
chemical_list: D000596:Amino Acids; D002264:Carboxylic Acids; D005559:Formamides; D011687:Purines; D011743:Pyrimidines; D014867:Water; C031066:formamide; D012313:RNA; D002244:Carbon