LIQUID-CHROMATOGRAPHY PURIFICATION AND STUDY OF URIDILYLPOLYNUCLEOTIDE-(5'P-]O)-TYROSINE PHOSPHODIESTERASE

LC has been used as a tool for studying uridilylpolynucleotide-(5'P--> O)-phosphodiesteras - an enzyme which hydrolyses specifically the phos phodiester band between picornaviral RNA and viral protein VPg. Accord ing to various chromatographic data, the enzyme forms two types of com plex with nucleic acids: weak ones which dissociate in 200 mM KCl, and others which are stable at concentrations up to 900 mM KCI. 2.5-3-fol d (preparative) or 6-fold (normal scale) purification of the enzyme wa s obtained by size-exclusion chromatography (SEC). Cation-exchange sep aration (4-fold purification) was found to be more suitable as the sec ond enzyme purification step than the earlier anion-exchange method us ed. Three forms of enzyme activity were discovered by hydrophobic-inte raction chromatography on the enzyme preparation obtained by SEC.