Table 1. Summary of Simulated Rate Constants for the HalM2/His₆P-HalA2 Reaction.

kx	best fit ± SE (min–1)	FitSpace boundaries (min–1)b	knet (μM–1 min–1)c	max concn (μM)d	processivity factore
kon	10a	held constant
koff	18	held constant
k7→8	17 ± 0.8	15.1–18.8	4.9		0.94
k8→9	61 ± 3	57.1–70.2	7.7	2.7	3.4
k9→10	25 ± 3	15.7–38.4	5.8	1.3	1.4
k9→14	104 ± 5	90.7–117	8.5	1.3	5.8
k10→15	104	fixed relative to k9→14	8.5	0.4	5.8
k14→15	81 ± 4	70.3–89.1	8.2	1.5	4.5
k15→16	36 ± 1.3	32.9–40.3	6.7	3.7	2.0
k16→17	16 ± 0.8	13.9–17.6	4.7	6.2	0.89
k17→18	23 ± 1.7	18.5–28.9	5.6	3.1	1.3
k16→19	2.5 ± 0.26	1.88–3.18	1.2	6.2	0.14
k17→20	5.0	fixed relative to k16→19	2.2	3.1	0.28
k18→21	20 ± 1.8	16.1–25.2	5.3	3.3	1.1
k19→20	19 ± 2.7	12–29.3	5.1	0.8	1.1
k20→21	32 ± 1.9	26.6–39.5	6.4	0.8	1.8
k21→22	58	fixed relative to k20→21	7.6	1.5	3.2
k22→4	41	fixed relative to k20→21	6.9	2.2	2.3

^ak_on is in units of μM^–1 min^–1.

^bFitSpace boundaries are given as 1.12 times the χ² minimum of the best fit. See Methods for additional details.

^ck_net = (k_onk_x)/(k_off + k_x). k_net is a second-order rate constant that serves as an approximation of k_cat/K_m.

^dRefers to the maximum observed concentration of the substrate for the indicated reaction. The total peptide concentration was 40 μM.

^eProcessivity factor is defined as k_x/k_off