Protease inhibitor (biology)
Protease inhibitors are molecules which proteins cleaving enzymes, peptidases (old name: proteases) inhibit, and prevent the breakdown of proteins can.
Properties
Natural protease inhibitors are often self- peptides or proteins. In addition, low molecular weight substances can inhibit the function of peptidases. Endogenous protease inhibitors serve the regulation of the function of peptidases. Some scorpion and snake venoms contain protease inhibitors, which are responsible for their toxicity. In drug therapy in particular protease inhibitors can be used against viral peptidases as drugs which, like, are HIV protease inhibitors or HCV protease inhibitors and antiviral drugs for the treatment of HIV infections, or HCV infections. In addition, directed against endogenous proteases protease inhibitors are used for example as anticoagulants or blood pressure medicines ( antihypertensives ).
There are four classes of proteases on their composition, and active site, which can be differently inhibited. In biochemistry, different protease inhibitors, in part, used as a mixture. However, this can be partially applied because of their toxicity only in vitro.
Serine proteases are inhibited by:
Cysteine proteases are inhibited by:
- E -64 and iodoacetamide
Metalloproteases are inhibited by:
- EDTA, citrate, and other chelators
Aspartic proteases are inhibited by:
- Pepstatin A
Leupeptin and alpha -2- macroglobulin inhibit several classes.