. Author manuscript; available in PMC: 2013 Oct 10.

Published in final edited form as: J Am Chem Soc. 2012 Sep 25;134(40):16717–16724. doi: 10.1021/ja3067429

Table 1.

Rates of cleavage for different hairpin ribozymes measured under single-turnover conditions in 25 mM HEPES (pH 7.5), 50 mM NaCl, 10 mM MgCl₂ at 25°C incorporating an unmodified substrate (5′-PO) or a 5′-phosphorothiolate linked substrate (5′-PS). Each rate constant is the average of ≥ 3 independent measurements.

ribozyme	5′-PO, k_obs/min⁻¹	5′-PS, k_obs/min⁻¹	5′-PS k_obs/5′-PO k_obs
natural ribozyme	0.51 ± 0.08	5.8 ± 0.8	11
none	u.d.^*	0.004 ± 0.003	--
ΔB ribozyme	u.d.^*	0.020 ± 0.002	--
G8DAP	0.011 ± 0.002	2.0 ± 0.2	180
G8I	0.02 ± 0.02	0.17 ± 0.03	8
A10U	0.0147 ± 0.0002	0.17 ± 0.003	12
C25U	0.014 ± 0.003	0.025 ± 0.002	2
A38P	0.00015 ± 0.00003	0.5 ± 0.1	3,600
G8DAP/A38P	u.d^*	0.14 ± 0.04	--

u.d. denotes a rate of < 10⁻⁵ min⁻¹, i.e. essentially undetectable activity after > 40 h incubation.