Table 5. Kinetics of representative exons in the suicide inhibition and reverse cyclization reactions as a function of MgCl₂ concentration^a.

^aBuffers consist of 50 mM HEPES (25 mM Na⁺), 4 or 15 mM MgCl₂ and 135 mM KCl at pH 7.5. Nucleobases that are bold and underlined represent deviations from the native 5′ exon sequence d(ATGAC)rU. An asterisk (*) indicates oligonucleotides that occur in the combinatorial assay.

^bThe error is the standard deviation of the measurements.

^cThe extent of reaction for the suicide inhibition reactions are reported relative to that obtained with r(AUGACU) at 4 mM MgCl₂ (actual extent of reaction = 32%). Similarly, the extent of reaction for the reverse cyclization reactions are reported relative to that obtained with r(AUGACU) at 15 mM MgCl₂ (actual extent of reaction = 17%). The relative extent of reaction is calculated by dividing the actual extent of reaction for each oligonucleotide by that for r(AUGACU) and multiplying by 100.

^dA dash (–) indicates no measurable activity.

^eNQ represents measurements that are not quantifiable due to inconsistent results with low product formation.