Antioxidant and mucolytic agent. Increases cellular pools of free radical scavengers. Reported to prevent apoptosis in neuronal cells but induce apoptosis in smooth muscle cells. Inhibits HIV replication. May serve as a substrate for microsomal glutathione transferase.
Catalase activates the decomposition of hydrogen peroxide, a reactive oxygen species, into water and oxygen. It functions as a natural antioxidant, protecting cells against oxidative damage to proteins, lipids and nucleic acids. Catalase has also been used to study the role reactive oxygen species play in gene expression and apoptosis.
Standard anti-malarial drug. Substrate for MRP in multidrug resistant cell line and inhibits photoaffinity labeling of MRP by quinoline-based photoactive drug IAAQ (N-[4-[1-hydroxy-2-(dibutylamino)ethyl]quinolin-8-yl]-4-azidosalicylamide).
DBeQ is a potent and specific inhibitor of ATPase p97, an integral component of the ubiquitin-fusion degradation (UFD) pathway. DBeQ inhibits the degradation of ubiquitinated proteins, the endoplasmic reticulum-associated degradation pathway, and autophagosome maturation. The compound also potently inhibits cellular proliferation and induces caspase 3/7 activity and apoptosis.
GMX1778 (CHS-828) is a competitive inhibitor of nicotinamide phosphoribosyltransferase (NAMPT) that exhibits a potent anticancer activity both in vitro and in vivo. GMX1778 exerts a cytotoxic effect by decreasing the cellular level of NAD+. GMX1778 increases intracellular ROS in cancer cells but does not induce ROS in normal cells.
Inhibitor of serine and cysteine proteases. Inhibits plasmin, trypsin, papain, calpain, and cathepsin B. Does not inhibit pepsin, cathepsins A and D, thrombin, or α-chymotrypsin. Effective concentration 10-100 μM. There have been numerous studies using leupeptin to protect against hearing loss caused by acoustic overstimulation or the ototoxic antibiotic gentamicin.1 (Loss of cochlear hair cells is believed to be mediated by calpain.)
Pepstatin A is an inhibitor of acid proteases (aspartyl peptidases). It forms a 1:1 complex with proteases such as pepsin, renin, cathepsin D, bovine chymosin, and protease B (Aspergillus niger). The inhibitor is highly selective and does not inhibit thiol proteases, neutral proteases, or serine proteases. Solubilized γ-secretase and retroviral protease are also inhibited by Pepstatin A. It has been used to characterize proteases from several sources.
Spautin-1 inhibits the activity of two ubiquitin-specific peptidases, USP10 and USP13, causing an increase in proteasomal degradation of class III PI3 kinase complexes, which have been shown to regulate autophagy.
Wortmannin is a potent and specific phosphatidylinositol 3-kinase (PI3-K) inhibitor with an IC50 of 2-4 nM. Inhibition of PI3-K/Akt signal transduction cascade enhances the apoptotic effects of radiation or serum withdrawal and blocks the antiapoptotic effect of cytokines. Inhibition of PI3-K by wortmannin also blocks many of the short-term metabolic effects induced by insulin receptor activation.