. Author manuscript; available in PMC: 2019 Jun 5.

Published in final edited form as: Biochemistry. 2018 Mar 26;57(22):3146–3154. doi: 10.1021/acs.biochem.8b00142

Table 3.

³¹P dipolar relaxation parameters (from field cycling) for NADP⁺ complexes of GMPR or mutant D219A with GMP, IMP or deoxy-substrates (dGMP and dIMP).

³¹P	Complex	N ^a	τ (ns)	R₀ (s⁻¹)	τ /R₀ × 10⁸(s²)
(d)IMP	WT•dIMP •NADP⁺	3	75 ± 30	0.8 ± 0.3	10 ± 5
(d)IMP	D219A•IMP •NADP⁺	2	70 ± 26	1.7 ± 0.3 (4.3 ± 0.7) ^c	4.1 ± 1.7 (1.6 ± 0.7) ^c
(d)GMP	WT•dGMP •NADP⁺	3	43 ± 12	0.4 ± 0.2	11 ± 6
(d)GMP	D219A•GMP •NADP⁺	4	120 ± 34	3.8 ± 1.2	3.1 ± 1.3
NADP⁺ mono-phosphate	WT•dIMP •NADP⁺	3	92 ± 18	0.8 ± 0.2	11 ± 3
	D219A•IMP •NADP⁺	2	139 ± 9	1.95 ± 0.02 (4.88 ± 0.05) ^c	7.1 ± 0.5 (2.8 ± 0.2) ^c
	WT•dGMP •NADP^{+ b}	3	75 ± 8	1.5 ± 0.5	5 ± 2
	D219A•GMP •NADP^{+ d}	4	125 ± 8	2.3 ± 0.3	5.3 ± 0.8
NADP⁺ diphosphates	WT•dIMP •NADP⁺	3	61 ± 23	0.3 ± 0.1	18 ± 8
	WT•dIMP •NADP⁺	3	85 ± 21	0.4 ± 0.1	23 ± 6
	D219A•IMP •NADP⁺	2	113 ± 6	0.60 ± 0.02 (1.50 ± 0.05) ^c	18 ± 1 (7.2 ± 0.4) ^c
	D219A•IMP •NADP⁺	2	112 ± 4	0.60 ± 0.04 (1.5 ± 0.1) ^c	18 ± 2 (7.2 ± 0.8) ^c
	WT•dGMP •NADP⁺	3	101 ± 27	1.6 ± 0.5	6.3 ± 3
	WT•dGMP •NADP⁺	3	98 ± 23	1.6 ± 0.4	6.2 ± 3
	D219A•GMP •NADP^{+ d}	4	137 ± 32	0.86 ± 0.15	16 ± 5
	D219A•GMP •NADP^{+ d}	4	114 ± 13	0.8 ± 0.1	15 ± 3

N is the number of independent experiments averaged to obtain the values tabulated.

R₀ corrected for the fraction of E•IMP•NADP⁺ compared to total enzyme (0.40).