Figure 8.

Absence of membrane defects after fiber formation as detected by paramagnetic quenching. (A and B) ³¹P chemical shift spectra of POPC/POPS/ganglioside LUVs before (top), after the addition of MSI-78 (A) and Aβ_1-40 (B) (middle), and after the addition of 500 μM Mn⁺² (bottom). Mn⁺² completely quenches the peaks originating from both the isotropic and lamellar phases in the MSI-78 sample, but only partially quenches the lamellar phase in the Aβ_1-40 sample, indicating the absence of membrane defects after fiber formation is complete. Aβ_1-40 was allowed to incubate on the membrane for 4 days before acquisition. All spectra were collected at 37°C and referenced with respect to 85% H₃PO₄ at 0.0 ppm.