ASPARTYLPROTEASE INHIBITOR AND METHOD OF IDENTIFYING THEREOF

beta -amyloid peptide ( beta AF) production in cell culture and in vivo is inhibited by administering aspartyl protease inhibitors, particularly inhibitors of proteases of cathepsin D. Useful aspartyl protease inhibitors can be selected in a two-step assay, where test compounds are first screened for aspartyl protease inhibition activity in vitro in noncellular assays. Those test compounds which are found to display protease inhibition activity are then tested in cellular assays for beta AP production inhibition. Those test compounds which are capable of inhibiting intracellular beta -amyloid production may be incorporated in pharmaceutical compositions.