Action of intercalating agents on the activity of DNA polymerase I

摘要: The effect of intercalating compounds such as 9-aminoacridine, quinacrine (atebrin), proflavine and daunomycin on the activity DNA polymerase I(EC 2.7.7.7) was studied in vitro compared with binding these acridines to native DNA. enzyme kinetics were followed at various concentrations 3'-OH primer end groups constant deoxynucleosidetriphosphates well under opposite conditions. Km values for 16--38 nM 2--5 micrometer, depending buffer pH used enzymatic assay. All acridine derivates inhibit polymerase; variable a competitive inhibition observed, where Ki ranged between 0.87 8.5 micrometer. At concentration non-competitive observed. On denatured poly(dA) - (dT)10 substrate no by 9-aminoacridine 5'--3' exonuclease is inhibited but 3'--5' not influenced this compound. affinity determined spectrophotometrically conditions similar those assay computed frequency intercalation related activity. mechanism explained disturbance structure double helical due interaction bound derivates.