[Synthetic ribonucleases. 1. Synthesis and properties of conjugates, containing an RNA-binding fragment based on lysine residues and an RNA hydrolyzing fragment, bearing an imidazole residue]. / Sinteticheskie ribonukleazy. 1. Sintez i svoistva kon''iugatov, soderzhashchikh RNK-sviazyvaiushchii fragment na osnove ostatkov lizina i RNK-gidrolizuiushchii fragment, nesushchii ostatok imidazola.

A series of RNA-hydrolyzing constructions was synthesized on the basis of peptide-like molecules containing residues of L-lysine, histamine and histidine methyl ester. These were shown to hydrolyze RNA effectively at neutral pH values. The in vitro transcript of tRNA(Lys) from human mitochondria and a tRNA-like fragment of RNA of Turnip Yellow Mosaic Virus were used in the experiments. Our chemical RNases quantitatively depolymerize some definite sequences (CA > or = UA > CG >> UC, CC, or CU) in both RNA molecules under optimum conditions. Moreover, no other sites were affected and no statistical hydrolysis was observed even after prolonged RNA incubation with the compounds of this series. The depolymerization rate of the RNA substrates exhibits a complex dependence on the concentration of ions of monovalent metals and on the concentration of the artificial ribonucleases.