NMR 1H,15N HSQC spectra of 90 μm15N-labeled Aβ(1–40) peptides in 20 mm sodium phosphate buffer at pH 7. 3, +5 °C, before (red) and after (blue) the addition of 18 μm α-lactalbumin (a), 5.4 μm albumin (b), 200 μm lysozyme (c), 50 μm β-lactoglobulin (d), 9 μm catalase (e), and 4.5 μm pyruvate kinase (f).