TABLE 3.

Effect of spin-labeled PTEN on relaxation parameters of short-chain phospholipids as measured by high resolution ³¹P field cycling

Ligand	[PTEN]/[PL]	τP-e	RP-e(0)	r6 × 1054 (m6)	rappa
		ns			Å
diC6PI	0.0016	172 ± 21	0.88 ± 0.05	3.80 ± 0.46	12.5 ± 0.3
diC6PI(4,5)P2	0.0017
P-1		37 ± 18	0.19 ± 0.04	4.0 ± 2.1	12.6 ± 1.1
P-4		35 ± 15	0.09 ± 0.01	8.0 ± 3.4	14.2 ± 1.1
P-5		32 ± 9	0.11 ± 0.01	6.0 ± 1.7	13.5 ± 0.6
diC8PIb	0.0007	200a	3.13 ± 0.36	0.54 ± 0.07	9.0 ± 0.2
diC8PI/Triton X-100 (1:2)cc	0.0007	68 ± 10	1.12 ± 0.07	0.52 ± 0.08	9.0 ± 0.2
diC8PI(4,5)P2	0.0016
P-1		128 ± 26	1.53 ± 0.15	1.6 ± 0.3	10.8 ± 0.4
P-4		131 ± 18	0.52 ± 0.03	4.9 ± 0.7	13.0 ± 0.3
P-5		99 ± 22	0.58 ± 0.06	3.3 ± 0.7	12.2 ± 0.4
diC8PI/diC8PI(4,5)P2	0.0016
P-1		103 ± 20	1.47 ± 0.13	1.4 ± 0.4	10.5 ± 0.4
P-4		169 ± 21	0.45 ± 0.03	7.4 ± 0.4	14.0 ± 0.3
P-5		153 ± 19	0.53 ± 0.03	5.7 ± 0.4	13.4 ± 0.3
diC7PCd	0.0011	120 ± 15	3.96 ± 0.24	0.40 ± 0.05	8.6 ± 0.2
diC7PC/Triton X-100 (1:2)	0.0011	118 ± 17	1.68 ± 0.15	0.94 ± 0.13	9.9 ± 0.2
diC7PC/diC8PI(4,5)P2e
P-1/PC		110 ± 13	1.79 ± 0.11
P-4	0.0018	93 ± 20	0.55 ± 0.03	3.7 ± 0.8	12.4 ± 0.4
P-5	0.0018	101 ± 25	0.68 ± 0.08	3.2 ± 0.8	12.2 ± 0.5

^a r_app is the ³¹P-e distance computed if the PR₁E is due to a single closest spin label, although not a real distance because other cysteines are spin-labeled, it does serve for comparing how different ligands bind.

^b The data for diC₈PI required fitting with two dispersions: for the slower one, the value of τ_P-e is 200 ns, and the value from the low field dispersion measured for the system with unlabeled PI-PLC was used for determining R_P-e(0). Error in τ was estimated as ±50 ns.

^c PI concentration was 3 mm.

^d The dispersion for diC₇PC was fit with a single τ_P-e.

^e The sample contained 5 mm diC₇PC and 3 mm diC₈PI(4,5)P₂; overlap of both phosphodiester resonances and similar relaxation profiles makes ascribing r_app⁶ to a particular phospholipid impossible.