Table 2.

Parameters extracted from high resolution field-cycling ³¹P NMR relaxometry data for the binding of deoxyphosphatidylinositols, cytotoxic alkylphospholipids, and diC₈PIP₃ to the spin-labeled Akt1 PH domain (37 μM).

Ligand	(mM)	τP-e (ns)	RP-e(0) (s−1)	rapp6 (m6)	rappa (Å)
D-3-deoxy diC8PI	3	41±3	6.08±0.22	1.01×10−54	10.1±0.1
L-3,5-dideoxy-  diC8PI	2	33±4	4.80±0.29	1.56×10−54	10.8±0.2
miltefosine b				0.83×10−54	9.7±0.2
perifosine b				1.41×10−54	10.6±0.7
diC8PIP3 (P-1) b				12.4×10−54	15.2±0.8

^aThe r_app reflects for the averaged distance of the ³¹P from the two spin-labels (although it is dominated by the nitroxide on Cys77).

^bThe field cycling parameters are from [17]. For diC₈PIP₃, only P-1, the phosphodiester nucleus, is reported for comparison to the phosphodiester ³¹P of the PIAs.