[An enzyme hydrolyzing the covalent bond between RNA and VPg of picornaviruses. Substrates and methods of analysis of activity].

Some new substrates--RNA-VPg, RNA-peptide and a small fragment of RNA peptide--labelled at the peptide component with [125I]Bolton-Hunter reagent have been proposed for use in the isolation and characterization of the enzyme hydrolyzing the phosphodiester bond between the VPg protein and encephalomyocarditis virus RNA. A novel procedure for the analysis of the specific enzyme activity is based on thin-layer chromatography of hydrolytic products on silicagel or polyethylenimine cellulose. The molecular mass of the enzyme isolated by a modified procedure involving FPLC is 90-95 kD.