Uracil‐Catalyzed Synthesis of Acetyl Phosphate: A Photochemical Driver for Protometabolism

Hagan, William J.

doi:10.1002/cbic.200900433

Cited by 17 publications

(11 citation statements)

References 34 publications

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“…This is the case for example of the transformations of aldehydes and ammonia into amino acid thioesters intermediates promoted by thiols (Wieland et al 1955a;Weber 1998) in agreement with the high chemical potential of sugars through redox disproportionation (Weber 2000). Moreover, a direct contribution of photochemistry to early metabolisms seems to be achievable for example through the photochemically assisted and uracil-catalyzed formation of acetyl phosphate from thioacetate recently described by Hagan (2010). Acetyl phosphate formed in this way could be sufficient to drive many protometabolic processes, but the comparison of free energy potential displayed in Table 2 makes the formation of aminoacyl adenylates unlikely from simple acyl phosphates.…”

Section: Ions Atoms Radicalsmentioning

confidence: 95%

Energy Sources, Self-organization, and the Origin of Life

Boiteau

Pascal

2010

Orig Life Evol Biosph

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The emergence and early developments of life are considered from the point of view that contingent events that inevitably marked evolution were accompanied by deterministic driving forces governing the selection between different alternatives. Accordingly, potential energy sources are considered for their propensity to induce self-organization within the scope of the chemical approach to the origin of life. Requirements in terms of quality of energy locate thermal or photochemical activation in the atmosphere as highly likely processes for the formation of activated low-molecular weight organic compounds prone to induce biomolecular self-organization through their ability to deliver quanta of energy matching the needs of early biochemical pathways or the reproduction of self-replicating entities. These lines of reasoning suggest the existence of a direct connection between the free energy content of intermediates of early pathways and the quanta of energy delivered by available sources of energy.

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Section: Ions Atoms Radicalsmentioning

confidence: 95%

Energy Sources, Self-organization, and the Origin of Life

Boiteau

Pascal

2010

Orig Life Evol Biosph

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“…Though the following analysis has not been developed in the original report, this observation strongly suggests that 5(4H)-oxazolone are the actual aminoacylating species and then that overactivation by cyclization also accounts for the observed reactivity of a-amino acid residues in peptides without specific neighbouring groups (Scheme 5). Substitutes for EDC, which was not likely to be present on the early Earth [namely, cyanamide (Lohrmann 1972;Brack 2007), cyanoacetylene (Orgel 2002), or isocyanides (Mullen and Sutherland 2007)] or photochemical processes (Hagan 2010) may have led to C-terminus activation. Therefore 5(4H)-oxazolones may be reasonably conceived as potential prebiotic intermediates.…”

Section: Intramolecular Reaction Of Activated Carboxyl Groupsmentioning

confidence: 99%

Activation of carboxyl group with cyanate: peptide bond formation from dicarboxylic acids

et al. 2011

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The reaction of cyanate with C-terminal carboxyl groups of peptides in aqueous solution was considered as a potential pathway for the abiotic formation of peptide bonds under the condition of the primitive Earth. The catalytic effect of dicarboxylic acids on cyanate hydrolysis was definitely attributed to intramolecular nucleophilic catalysis by the observation of the 1H-NMR signal of succinic anhydride when reacting succinic acid with KOCN in aqueous solution (pH 2.2-5.5). The formation of amide bonds was noticed when adding amino acids or amino acid derivatives into the solution. The reaction of N-acyl aspartic acid derivatives was observed to proceed similarly and the scope of the cyanate-promoted reaction was analyzed from the standpoint of prebiotic peptide formation. The role of cyanate in activating peptide C-terminus constitutes a proof of principle that intramolecular reactions of adducts of peptides C-terminal carboxyl groups with activating agents represent a pathway for peptide activation in aqueous solution, the relevance of which is discussed in connexion with the issue of the emergence of homochirality.

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“…Also, prolonged UV irradiation in this approach destroyed a plethora of side products so that canonical pyrimidine nucleotides prevailed as ultimate survivors-ribocytidine primarily, from which ribouridine arose by UV-induced conversion. Moreover, consolidating the thioester-to-phosphate relay mentioned above, uracil itself has photo-catalytic activity by facilitating the synthesis of acetyl phosphate from thioacetate by UV light [ 95 ], considered to represent a key reaction in protometabolic networks.…”

Section: Molecular Ecosystems In Biogenic Photochemical Reactorsmentioning

confidence: 99%

Primal Eukaryogenesis: On the Communal Nature of Precellular States, Ancestral to Modern Life

Egel

2012

Life

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This problem-oriented, exploratory and hypothesis-driven discourse toward the unknown combines several basic tenets: (i) a photo-active metal sulfide scenario of primal biogenesis in the porespace of shallow sedimentary flats, in contrast to hot deep-sea hydrothermal vent conditions; (ii) an inherently complex communal system at the common root of present life forms; (iii) a high degree of internal compartmentalization at this communal root, progressively resembling coenocytic (syncytial) super-cells; (iv) a direct connection from such communal super-cells to proto-eukaryotic macro-cell organization; and (v) multiple rounds of micro-cellular escape with streamlined reductive evolution-leading to the major prokaryotic cell lines, as well as to megaviruses and other viral lineages. Hopefully, such nontraditional concepts and approaches will contribute to coherent and plausible views about the origins and early life on Earth. In particular, the coevolutionary emergence from a communal system at the common root can most naturally explain the vast discrepancy in subcellular organization between modern eukaryotes on the one hand and both archaea and bacteria on the other.

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Uracil‐Catalyzed Synthesis of Acetyl Phosphate: A Photochemical Driver for Protometabolism

Cited by 17 publications

References 34 publications

Energy Sources, Self-organization, and the Origin of Life

Energy Sources, Self-organization, and the Origin of Life

Activation of carboxyl group with cyanate: peptide bond formation from dicarboxylic acids

Primal Eukaryogenesis: On the Communal Nature of Precellular States, Ancestral to Modern Life

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