Table 1. Fit parameters for frequency-domain lifetime data.

Donor	Acceptor		Recovery	τD1 (ns)	α1	τD2 (ns)	${\displaystyle {\overline{r}}_{D1}}$(Å)	σ1 (Å)	${\displaystyle {\overline{r}}_{D2}}$(Å)	σ2 (Å)	A2 0.2 mM	A2 0.37 mM
Anap	n/a
		Mean		1.3	0.76	3.3
		SEM		0.02	0.003	0.02
		n		4	4	4
Acd	n/a
		Mean		16.0
		SEM		0.03
		n		4
MBP-295Acd-Y307F-C	Cu2+-TETAC
		Mean	0.92	15.6			23.7	6.2	13.4	6.5
		SEM	0.040	0.05			0.36	0.47	0.38	0.27
		n	10	10			10	10	7	7
MBP-322Acd-C	Cu2+-TETAC
		Mean	0.94	15.1			13.6	5.3	15.8	5.5
		SEM	0.015	0.09			0.06	0.22	0.09	0.15
		n	5	5			5	5	4	4
MBP-295Acd-Y307F-HH	Cu2+
		Mean	0.88	15.5			18.3	2.5	12.7	1.3	0.38	0.60
		SEM	0.040	0.07			0.21	0.54	0.04	0.26	0.002	0.02
		n	5	5			3	3	4	4	3	3
MBP-295Acd	n/a
		Mean		14.0	0.70	2.0
		SEM		0.14	0.011	0.08
		n		5	5	5

${\displaystyle {\overline{r}}_{D1}}$ and σ₁ are from fits to the data in the absence of maltose. ${\displaystyle {\overline{r}}_{D2}}$ and σ₂ are from fits to the data in the presence of 10 mM maltose. Recovery refers to fits to the data in the presence of TCEP, for Cu²⁺-TETAC, and EDTA, for Cu²⁺.