The results listed in Table show that the best-fit values of all three adjustable model parameters are in reasonably good agreement with the "true" (i.e., simulated) values. In particular, the best-fit value of the active enzyme concentration is [E] 0 = 12.5 nM, while the simulated "true" value was 10 nM, representing an agreement within 25% systematic error. Very similar results were obtained for the association rate constant k on (simulated "true" value 0.1 µM -1 s -1 , best-fit value 0.125 µM -1 s -1 ). The best-fit value of the dissociation rate constant k off agrees with the "true" value within 10%, but also note that the non-symmetrical confidence interval is approximately one order of magnitude wide (from 0.02 to 0.27 msec -1 ).