The methodologies of the present invention demonstrate that a critical balance between pro- and anti-amyloidogenic molecules exists that regulates amyloid formation and cell death in Alzheimer's disease and Parkinson's disease. beta -Synuclein, the non-amyloidogenic homologue of alpha -synuclein, is a negative modulator of alpha -synuclein and A beta aggregation, having neuroprotective properties against alpha -synuclein and A beta neurotoxicity and that beta -synuclein and therapeutic agents derived therefrom block amyloidogenesis and neurodegeneration <i>in vivo</i>. The method of the present invention establishes that beta -synuclein blocks A beta aggregation either by direct inhibition of A beta amyloidogenesis or indirectly via either alpha -synuclein or its 35 a.a. NAC region, inferring neuroprotective characteristics within the effected cells. The generation of a transgenic mouse line and a cell-free system overexpressing alpha -synuclein characterizes the mechanisms by which beta -synuclein blocks alpha -synuclein and A beta aggregation and that this mechanism offers protection to the cell against amyloid formation as seen in the pathologies of Alzheimer's disease and Parkinson's disease.
METHOD FOR SCREENING FOR ANTI-AMYLOIDOGENIC PROPERTIES AND METHOD FOR TREATMENT OF NEURODEGENERATIVE DISEASE