Table 1.

PKA binding rates.^a

	Single-Molecule						Ensemble
ATP	τ	±	σ	<t>	±	σ	<t>
bound (ms)	1.99	±	0.03	3.1	±	4.3	5.329
unbound (ms)	0.77	±	0.01	5.0	±	19	> 0.25b
binding / unbind- ing cycle (s−1)	362c	±	5	125d			< 190b,e
Kemptide	τ	±	σ	<t>	±	σ	<t>
bound (ms)	0.77	±	0.01	1.8	±	2.9	<230
Unbound (ms)	0.67	±	0.01	1.7	±	3.7	<2017
binding / unbind- ing cycle (s−1)	696c	±	8	286d			>46

^aWhere τ is the characteristic time from an exponential fit to the data reported in Figure 3, and <t> is the arithmetic mean from the distribution shown in Figure 3.

^bEstimated by extrapolation to saturation conditions from the experimental data of Ni et al.²⁹

^c1/(τ_bound + τ_unbound)

^d1/(<t_bound> + <t_unbound>

^eEstimated from ligand exchange with AMP-PNP.