. Author manuscript; available in PMC: 2020 Apr 16.

Published in final edited form as: Biochemistry. 2020 Mar 30;59(14):1442–1453. doi: 10.1021/acs.biochem.0c00001

Table 1.

dCDP formation kinetics at varying ratios of α:β in the absence of reductant.

α₂ (μM)	β₂ (μM)	First phase			Second phase			k_cat^b (s⁻¹)
α₂ (μM)	β₂ (μM)	k₁ (s⁻¹)	dCDP/ α₂	dCDP/Y•^a	k₂ (s⁻¹)	dCDP/α₂	dCDP/Y•^a	k_cat^b (s⁻¹)
10	10	6 (1)	1.3 (2)	1.1 (1)	0.51 (8)	1.6 (2)	1.3 (1)	8 (1)
10	1	0.8 (2)	1.4 (1)	10 (1)	0.030 (7)	1.1 (1)	11 (1)	8 (2)
10	0.1	0.046 (2)	2.5 (1)	207 (3)	–	–	–	9.5 (4)
1	1	6 (1)	1.5 (2)	1.2 (1)	0.9 (1)	1.5 (2)	1.2 (1)	8 (1)

Y• amount used in the dCDP/ Y• calculation was obtained from the moles of β₂ (87,000 g/mol) in the reaction mixture and the amount of radical per dimer (1.2).

k_cat = A₁k₁ + A₂k₂, where A_n refers to the amplitude with respect to Y•.