Figure 4.

Membrane insertion properties of the N-terminal region of NTAc-αS using PREs. ssNMR PRE of membrane bound NTAc-αS were measured by doping to DOPE:DOPS:DOPC SUVs with 2% of lipid molecules having a paramagnetic centre in different positions ranging from the hydrophilic head group (1-palmitoyl-2-stearoyl-[5-doxyl]-sn-glycero-3-phosphocholine) to the position of carbons 5, 10 and 16 of the lipid tail (1-palmitoyl-2-stearoyl-[N-doxyl]-sn-glycero-3-phosphocholine, N = 5, 10, 16). The chemical structures of the paramagnetically labelled lipids are shown in the corresponding spectra. ¹³C-¹³C-DARR spectra of these samples were measured at −19 °C to favour the gel phase of the membrane⁴⁴, and using 1 ms and 50 ms for contact and mixing times, respectively. The experiments were performed at a ¹H Larmor frequency of 700 MHz using a 3.2 mm E^Free probe and a MAS rate of 10.0 kHz. Spectra in the presence and absence of the paramagnetic lipids are shown in green and red, respectively.