α-1-Antichymotrypsin interaction with Aβ (1–40) inhibits fibril formation but does not affect the peptide toxicity

Abstract

Recent studies have shown that senile plaque-associated or glial-derived proteins can prevent fibril formation of β-amyloid peptide (Aβ), while increasing the neurotoxicity of the latter (in the case of glutamine synthetase, apolipoprotein J or thrombin). α-1-Antichymotrypsin (ACT) is a glial-derived protein associated with senile plaques in the Alzheimer's brain. In this report we show that ACT, a minor protein component of β-amyloid deposits, is able to inhibit Aβ (1–40) aggregation into fibrils, but unable to modulate the toxicity of Aβ (1–40) in primary rat hippocampal cell cultures. These results are discussed in terms of the potential role of glial-derived proteins on Aβ aggregation and neurotoxicity.