The amyloid peptides Aβ1–42 and Aβ25–35 strongly inhibited the activity of constitutive
neuronal and endothelial nitric oxide synthases (ie, NOS‐I and NOS‐III, respectively) in cell‐
free assays. The molecular mechanism of NOS inhibition by Aβ fragments was studied in
detail with Aβ25–35. The inhibitory ability was mostly NADPH‐dependent and specific for
the soluble form of Aβ25–35. Optical, fluorescence, and NMR spectroscopy showed that the
soluble, but not aggregated, Aβ25–35 interacted with NADPH, thus suggesting that a direct …

The amyloid peptides Aβ1-42 and Aβ25-35 strongly inhibited the activity of constitutive
neuronal and endothelial nitric oxide synthases (ie, NOS-I and NOS-III, respectively) in
cellfree assays. The molecular mechanism of NOS inhibition by Aβ fragments was studied in
detail with Aβ25-35. The inhibitory ability was mostly NADPH-dependent and specific for the
soluble form of Aβ25-35. Optical, fluorescence, and NMR spectroscopy showed that the
soluble, but not aggregated, Aβ25-35 interacted with NADPH, thus suggesting that a direct …