. Author manuscript; available in PMC: 2020 Apr 6.

Published in final edited form as: ACS Catal. 2019 Jul 2;9(8):6955–6961. doi: 10.1021/acscatal.9b02054

Table 1.

Kinetic Parameter Characterizations of EgtBCth Wild-Type and Variants

enzyme	substrates	k_cat (min−1)	K_{M, hercynine}(μM)	k_{cat/ KM, hercynine}(min−1μM−1)	K_{M, γ‑Glu‑Cys/Cys} (μM)	k_{cat/ KM, γGluCys/Cys}(min−1μM−1)	% of coupling product
wild-type	2 + γ-Glu-Cys	17.5 ± 0.4	41.4 ± 3.5	0.42 ± 0.04	(5.9 ± 0.9)E3	(3.0 ± 0.5)E-3	75%
	2 + L-Cys	26.6 ± 0.7	87.7 ± 7.6	0.30 ± 0.03	205 ± 18	0.13 ± 0.01	72%
A420Y	2 + γ-Glu-Cys	17.4 ± 0.3	13.2 ± 1.3	1.3 ± 0.1	(3.1 ± 0.3)E3	(5.6 ± 0.6)E-3	61%
	2 + L-Cys	27.6 ± 0.5	39.2 ± 1.6	0.70 ± 0.03	28.1 ± 1.8	0.98 ± 0.06	76%
D52L	2 + γ-Glu-Cys	12.9 ± 0.2	19.6 ± 1.4	0.66 ± 0.05	(3.9 ± 0.3)E3	(3.3 ± 0.2)E-3	50%
	2 + L-Cys	27.6 ± 0.5	13.2 ± 1.3	2.1 ± 0.2	47.3 ± 2.4	0.58 ± 0.03	69%
D52L/A420Y	2 + γ-Glu-Cys	18.6 ± 0.4	15.1 ± 1.3	1.2 ± 0.1	(4.2 ± 0.5)E3	(4.4 ± 0.5)E-3	52%
	2 + L-Cys	32.7 ± 0.3	23.3 ± 1.2	1.4 ± 0.07	48.7 ± 3.5	0.67 ± 0.04	75%