Pepstatin (Pepsin Inhibitor S 735A) is an aspartate protease inhibitor that also inhibits HIV protease activity with specific and oral activity. Pepstatin inhibits autophagy.

Hemoglobin-pepsin:4.5 nM, Casein-pepsin:150 nM, Casein-proctase:290 nM, Hemoglobin-proctase:6.2 nM, Hemoglobin-acid protease:260 nM, Casein-acid protease:520 nM

方法: F.pedrosoi 硬化细胞用 Pepstatin (0.1-20 µM) 处理 20 h，通过 CFU assay 检测细胞活力。
结果: Pepstatin 能够以典型的剂量依赖方式阻断硬化细胞的存活率。[1]
方法: SV40 转化的皮肤成纤维细胞用 Pepstatin (100 µM) 处理 1 h，然后在 1% FCS 中与 doxorubicin (1 µM) 或 TNF-α (50 ng/mL) 孵育 48 h，通过 MTT assay 检测细胞活力。
结果: 用 100 µM Pepstatin 预处理人细胞后，cathepsin D 活性受到强烈抑制。尽管有这种抑制作用，但在成纤维细胞中由 doxorubicin 或 TNF-α 诱导的细胞死亡并没有被 Pepstatin 阻止。[2]

方法: 为检测体内抑制动力学，将 Pepstatin (25-200 mg/kg) 腹腔注射给 CD-1 小鼠。
结果: 在肝脏中，cathepsin D 的显著抑制至少持续 15 天，而在心脏和骨骼肌中，这种抑制持续的时间要短得多。酶活性恢复到正常值是剂量依赖性的，在相同的剂量水平下，这些器官组织的酶活性恢复存在显著差异，其中肝脏是最敏感的。[3]

Pepstatin A is freshly dissolved in DMSO at 7 mM. It is very slowly diluted (1:100) into the medium of HIV-infected H9 suspension cultures so that no pepstatin A precipitated (final concentration, 70 μM pepstatin A and 1% DMSO), and the cultures are incubated without change of culture medium for 48 hr. As a control, uninfected H9 cells are also incubated with pepstatin and in addition HIV infected and uninfected cells are incubated with 1% DMSO but without pepstatin [2].

To investigate the effect of pepsins on bacterial motility, similar experiments were performed, but the pepsin in the stomach was inactivated by rinsing the stomach with pepstatin (100 μl of a 2-mg/ml stock solution). Samples were taken and analyzed for bacterial motility at the test pH values of 2.0, 3.0, 4.0, 4.5, and 5.0 and at the same periods after application of the bacterial suspension as in the experiments with active pepsins [4].