Patent ID: 7368536

Claim:
A purified or isolated polypeptide that comprises an amino acid sequence selected from the group consisting of: (a) the amino acid sequence set forth in SEQ ID NO: 4; (b) a fragment of (a) that exhibits aspartyl protease activity involved in processing APP into amyloid beta and includes aspartyl protease active site tripeptides DTG and DSG; (c) a conservative substitution variant of (a) or (b) having an amino acid sequence identical to (a) or (b) except for conservative substitutions, wherein the conservative substitution variant comprises an amino acid sequence encoded by a nucleic acid molecule that hybridizes under the following stringent hybridization conditions to the complement of SEQ ID NO: 3: (1) hybridization at 42° C. in a hybridization buffer comprising 6×SSC and 0.1% SDS, and (2) washing at 65° C. in a wash solution comprising 1×SSC and 0.1% SDS; wherein the conservative substitution variant exhibits aspartyl protease activity involved in processing APP into amyloid beta.