Table 1.

Proteases classification: Classification of proteases on the basis of their catalytic mechanism (Hartley [2]).

Type	Specific Inhibitors: characteristics of enzyme type	Other Inhibitors	Activators
Aspartic proteinases (EC 3.4.23)	Pepstatin S-PI (acetyl pepstatin) Diazoacetyl norleucine methyl ester N— Diazoacetyl-N-‘ − 2,4- dinitrophenylethylenediamine Epoxy (p-nitrophenoxy) propane
Metalloproteinases (EC 3.4.24)	Chelating agents EDTA, ethylene glycol-bis- (β- aminoethyl ether)- N, N- tetraacetic acid o-phenanthroline 8- hydoxyquinoline α,α- dipyridyl Phosphoramidon (not acid metalloproteinases
Serine proteinases (EC 3.4.21)	PMSF DIFP	TLCK TPCK Antipain Leupeptin Chymostatin
Cysteine proteinases (EC 3.4.22)	Iodoacetamide, iodoacetate Heavy metals N-ethyl maleimide	p-Chloromercurinenzoate (also inhibits some serine proteases) TLCK TPCK Antipain Leupeptin Chymostatin	Reducing agents Cysteine DTT EDTA