title: Activation of carboxyl group with cyanate: peptide bond formation from dicarboxylic acids.
abstract: 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.
authors.affiliation: Spectrométries et Dynamique Moléculaire, Physique des Interactions Ioniques et Moléculaires Université de Provence, Université Aix-Marseille I, Centre Saint-Jérôme, Case 252, 13397, Marseille, France. gregoire.danger@univ-provence.fr
authors.forename: Grégoire
authors.initials: G
authors.lastname: Danger
authors.forename: Solenne
authors.initials: S
authors.lastname: Charlot
authors.forename: Laurent
authors.initials: L
authors.lastname: Boiteau
authors.forename: Robert
authors.initials: R
authors.lastname: Pascal
mesh_terms: D000577:Amides / Q000737:chemistry*; D000596:Amino Acids / Q000737:chemistry*; D000812:Anhydrides / Q000737:chemistry; D002384:Catalysis; D003485:Cyanates; D003998:Dicarboxylic Acids / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D010455:Peptides / Q000737:chemistry*; D012996:Solutions; D014867:Water / Q000737:chemistry
chemical_list: D000577:Amides; D000596:Amino Acids; D000812:Anhydrides; D003485:Cyanates; D003998:Dicarboxylic Acids; D010455:Peptides; D012996:Solutions; D014867:Water; C024835:potassium cyanate