Pepstatin A

Description: Pepstatin A, a pentapeptide, is a potent and selective aspartic protease inhibitor which also inhibits HIV replication. Pepstatin A was originally isolated from the microbe. It has IC50s of 4.5 nM, 6.2 nM, 150 nM, 290 nM, 520 nM and 260 nM for hemoglobin-pepsin, hemoglobin-proctase, casein-pepsin, casein-proctase, casein-acid protease and hemoglobin-acid protease, respectively. As a most potent renin inhibitor, pepstatinA inhibited porcine renin and human renin at weak acid pH value with IC50 values of 0.32 and 15 uM, respectively. Pepstatin A shows effective inhibition on aspartic proteinases such as pepsin, cathepsins D and E. In HIV-infected H9 cells, pepstatin A inhibits part of the intracellular processing of the HIV gag protein with no apparent toxicity on HIV-infected cells. Pepstatin A also suppresses the differentiation of osteoclasts by blocking ERK signaling and the inhibition of NFATc1 expression.

References: Proc Natl Acad Sci U S A. 1988 Sep; 85(18):6612-6; J Biochem. 2006 Mar; 139(3):583-90.