Figure 4.

Fluorescence assays of the cleavage reactions that contained substrates with AF488 labeled at −2 and QSY9 at +2. A mixture of Mg²⁺ and Mn²⁺ [abbreviated as ‘M(II)'] was added after the fifth minute to trigger the reactions. Open circles and closed squares indicate the signal variation (F/F_o) derived from two independent cleavage reactions that contained 8-17 deoxyribozyme. Inset shows the phosphorimage of the reaction products separated by denaturing PAGE after ∼2 h incubation with and without the divalent metal ions. S, substrate; P, cleavage product.