title: [Effect of various factors on the methylation of DNAse I].
abstract: The effects of NaCl, EDTA and tRNA on methylation and enzymatic properties of deoxyribonuclease I (DNase I) were investigated. The methylation was carried out by S-methylmethionine (vitamin U) in the phosphate-citric buffer pH 4.0. It was found that 0.5 M NaCl decreases by about 30% the incorporation of CH3-groups into the DNase, whereas 1.5 M NaCl-by 47%. A similar, although a less pronounced effect, was exerted by tRNA within the concentration range of 1.36-34.7 microM. On the contrast, EDTA (0.01-0.05 M) stimulated the incorporation of CH3-groups by 15 and 30%, respectively. The functional properties of methylated DNase I in the presence of EDTA remained unaffected. The enzyme methylation in the presence of NaCl or tRNA caused deceleration of the 3H-DNA hydrolysis (by 15-30%) only within the first 20 min of the reaction.
mesh_terms: D003850:Deoxyribonuclease I / Q000378:metabolism*; D004492:Edetic Acid / Q000494:pharmacology; D006868:Hydrolysis; D066298:In Vitro Techniques; D008745:Methylation; D012343:RNA, Transfer; D012965:Sodium Chloride / Q000494:pharmacology; D014814:Vitamin U / Q000494:pharmacology*; D014815:Vitamins / Q000494:pharmacology*
chemical_list: D014815:Vitamins; D014814:Vitamin U; D012965:Sodium Chloride; D012343:RNA, Transfer; D004492:Edetic Acid; D003850:Deoxyribonuclease I
vernacular_title: Vliianie nekotorykh faktorov na reaktsiiu metilirovaniia DNKazy I.