Fig. 1. HNP-1 exhibits general inhibition properties against the fibrillization of different amyloid peptides. (a) Sequence and structure of α-defensin HNP-1 with a β-rich structure. (b) Dose-dependent inhibition effect of HNP-1 on Aβ, hIAPP, and hCT aggregation by ThT fluorescence assays. Inhibition efficiency of HNP-1 is determined by the relative final fluorescence intensity (%) normalized by that of pure amyloid aggregation. Equivalent value of HNP-1 is defined by the molar ratio of the HNP-1 : amyloid peptide. Error bar represents the standard deviation (s. d.) of triplicate measurements. (c) TEM image of 25 μM Aβ, hIAPP, and hCT in the absence or presence of an equimolar concentration of HNP-1. Samples were prepared after 3 days of incubation in a physiological environment (pH 7.4 and 37 °C). Scale bars = 200 nm. (d) SDS-PAGE characterization of 25 μM Aβ, hIAPP, and hCT homo-/hetero-assemblies in the absence or presence of 25 μM HNP-1. (e) Circular dichroism (CD) spectra of 25 μM Aβ, hIAPP, and hCT in the absence (gray diamond, control) or in the presence of HNP-1 after 0, 0.5, 1 and 3 days of incubation. HNP-1 was added to Aβ or hIAPP solution at 25 μM, but to hCT solution at 10 μM.