Fig. 5. Access of the Notch-TMD backbone amide protons to water-soluble (Gd-DTPA) and lipophilic (16-DSA) paramagnetic probes in bicelles containing lipids of different types and chain lengths.

Short chain, DMPC; medium chain, ESM; long chain, MSM. I_exp/I_ref is the ratio of the NMR peak intensities for each site in the presence of the probe versus the intensity for that same site under matched diamagnetic conditions. The solid vertical lines indicate the length of the α helix that spans the TMD. The DMPC accessibility plots represent the average of two matched trials, one of which was previously reported (40).