[Abiotic synthesis of peptides containing a dicarboxylic acid and their catalytic properties].

Studies have been made on thermal synthesis of peptides containing amino acids (glycine, alanine, leucine, threonine, and histidine) and succinic acid. The synthetic products were found to be heterogeneous, comprising mostly linear polymers. In the peptides obtained, the ratio between individual amino acids differed from the initial one. It was demonstrated that glycine exhibits high capacity for polymerization. At the same time, most polymerized peptides contained large amounts of leucine. In hydrolyzates of some of the peptides, a new non-identified amino acid was found which was formed from threonine. The peptides obtained exhibited catalytic properties: they hydrolyzed-p-nitrophenyl-phosphate, increased the breakdown of ascorbic acid by hydrogen peroxide and splitted inorganic phosphate from ATP. These activities depended on PH of the medium, the duration of action and substrate concentration. Synthetic products which contained threonine residues, exhibited higher activities as compared to other peptides. The data obtained reveal a possibility of incorporating the organic acids into polypeptide chains during abiogenic synthesis of biologically active substances. Such compounds with non-specific catalytic properties could serve as one of the steps in evolution of biocatalyzers.