Abstract: A proteolytic enzyme isolated from human tissue which exhibits a proteolytic activity to hydrolyze Met-Asp peptide bond in an amyloid-like substrate is disclosed. This enzyme has been designated "amyloidin" because it proteolytically cleaves a Met-Asp bond similar to the one present in the amyloid precursor protein to release a fragment having the mature Asp terminus of the .beta.-amyloid peptide. Antibodies to the amyloidin protease are also provided. Methods to isolate and purify the amyloidin protease are provided, as well as assays to screen for inhibitors of the amyloidin protease. Also disclosed is the gene encoding the protease and methods for expression of the protease by recombinant DNA means.

Abstract: A proteolytic enzyme isolated from human tissue which exhibits a proteolytic activity to hydrolyze Met-Asp peptide bond in an amyloid-like substrate is disclosed. This enzyme has been designated "amyloidin" because it proteolytically cleaves a Met-Asp bond similar to the one present in the amyloid precursor protein to release a fragment having the mature Asp terminus of the .beta.-amyloid peptide. Antibodies to the amyloidin protease are also provided. Methods to isolate and purify the amyloidin protease are provided, as well as assays to screen for inhibitors of the amyloidin protease. Also disclosed is the gene encoding the protease and methods for expression of the protease by recombinant DNA means.