Figure 4.

Sequence preference of Endo IV. The activity of Endo IV was determined by measurement of the amount of acid-soluble nucleotides released from the substrate (10 μM). A series of 19 base 5′-(dA)₈dDdCdD(dA)₈-3′ oligonucleotides (A) and a series of 21 base 5′-(dA)₈dDdTdCdAdD(dA)₈-3′ oligonucleotides (B) were used as substrates, where dD represents dA, dT or dG. The relative activity was calculated by dividing the enzymatic activity for each oligonucleotide by that for 5′-(dA)₈dAdCdA(dA)₈-3′ or (dC)₂₅ in (A) or by that for 5′-(dA)₈dAdTdCdAdA(dA)₈-3′ or (dC)₂₅ in (B). Data are means from two independent experiments.