. Author manuscript; available in PMC: 2012 Apr 5.

Published in final edited form as: Biochemistry. 2011 Mar 11;50(13):2424–2433. doi: 10.1021/bi101842u

Table 1.

Apparent K_ds and maximum cleavage rates (k_obs^max) for complex-initiated reactions^a employing a variety of cations at pH 7.5

Cation	K_d^app^b	k_obs^max, min¹	n
Na⁺	1.5 M	1.2	2.7
Mg²⁺	10 mM	3.6	2.0
Ca²⁺	6 mM	3.4	2.5
Mn²⁺	2.5 mM	0.77	1.5
Co(NH₃)₆³⁺	0.28 mM	0.33	1.3

The complex-initiated experimental design is outlined in Figure 1B and described in Experimental Procedures.

K_d values were determined by fitting k_obs vs cation concentration plots to the Hill equation, as described in Experimental Procedures, where the value for the Hill coefficient (n) is shown above for each cation tested.