FIGURE 6.

Field dependence of the PR₁E for diC₆PI and diC₆PI(4,5)P₂. A, R₁ for the ³¹P of diC₆PI (3 mm) caused by 4.9 μm spin-labeled PTEN; the inset shows the ΔR₁ of this phosphodiester from 0.004 to 4 T after subtraction of the profile obtained using nonlabeled PTEN. B, R₁ for the ³¹P resonances of diC₆PI(4,5)P₂ (3 mm) in the presence of 5.1 μm spin-labeled PTEN: P-1 (●), P-4 (▵), and P-5 (▴). The inset in B shows the R₁ profile for 3 mm I(1,4,5)₃ in the presence of 4.9 μm spin-labeled PTEN: P-4 (●), P-1 phosphate (○), and P-5 phosphate (□). Note that none of these ³¹P resonances exhibit the low field rise in R₁ indicative of a small molecule-protein complex. Error bars for R₁ values (here and in subsequent plots) were obtained from a least squares fit of the ln(intensity) versus time determining R₁ at that particular field.