. 2012 Jun 25;287(34):28802–28815. doi: 10.1074/jbc.M112.381624

TABLE 1.

Values of kinetic parameters for TrCel7A from single-turnover experiments

Enzyme(s)^a	[¹⁴CB]_max^b	[ES]_trap^c	P_app^d	k^b	k_cat^e
	μm	μm	CB units	s⁻¹	s⁻¹
TrCel7A	15 ± 2	0.22 ± 0.10	66 ± 7^f	0.033 ± 0.006^f	2.2 ± 0.5^f
TrCel7A + EG	34 ± 2	0.67 ± 0.01	50 ± 3	0.030 ± 0.005	1.5 ± 0.2
CD_Tr_Cel7A	4.9 ± 0.5			0.089 ± 0.05
CD_Tr_Cel7A + EG	11 ± 2	0.28 ± 0.02	40 ± 6	0.031 ± 0.025	1.2 ± 0.4

^a Experimental conditions were as follows: [¹⁴C-BC] = 0.5 mg ml⁻¹, [TrCel7A] or [CD_Tr_Cel7A] = 1.0 μm, [β-glucosidase] = 0.125 μm, 25 °C, pH 5.0. If present, the concentration of EG (TrCel5A) was 0.1 μm. An AC trap was added after 10 s of hydrolysis.

^b Values of [¹⁴CB]_max and k were found by non-linear regression of [¹⁴C-cellobiose] released under single-turnover conditions according to Equation 1.

^c Concentration of TrCel7A at the moment of trap addition ([ES]_trap) represents the population of TrCel7A with the active site occupied by the cellulose chain ([TrCel7A]_OA) after 10 s of hydrolysis.

^d Apparent processivity of TrCel7A (P_app, in cellobiose units) was found from the values of [¹⁴CB]_max and [ES]_trap according to Equation 3.

^e The value of k_cat was found from the values of k and P_app according to Equation 5.

^f These values are averages over values obtained at different TrCel7A concentrations and at different times of trap addition (supplemental Table S1).