Pepstatin Ammonium is a specific inhibitor of aspartic proteaseproduced by actinomycetes(hemoglobin-pepsin, hemoglobin-proctase, casein-pepsin, casein-proctase, casein-acid protease and hemoglobin-acid protease with IC50s of 4.5 nM, 6.2 nM, 150 nM, 290 nM