Figure 3.

Paramagnetic quenching of IAPP bound to LysoPG in the absence and presence of calcium. (A and B) ¹H chemical shift projections of 2D ¹⁵N-¹H SOFAST-HMQC spectra of 150 μM IAPP bound to 25 mM LysoPG in the absence (A) and presence (B) of 12.5 mM calcium with the indicated MnCl₂ concentration (full 2D NMR spectra are shown in Fig. S9 and Fig. S10). Manganese has a moderate effect on IAPP in the absence of calcium; the more-severe effect in the presence of calcium is an indication of greater solvent exposure of hIAPP when bound to the micelle. All experiments were performed in 20 mM Tris buffer, 25 mM NaCl, pH 7.4.