(Nle³⁵)-Amyloid β-Protein (1-40)

The reactive thioether of Met³? is crucial for the activity of Aβ 1-40 and Aβ 1-42. Due to the replacement of Met by inert Nle, M35Nle Aβ 1-40 was no longer toxic to cultured hippocampal neurons and had little effect on the level of protein carbonyl residues. The Nle peptide showed the same propensity to aggregate, whereas sulfoxide formation hindered the required conformational transition from random coil to β-sheet.