title: Modes of inhibition of cysteine proteases.
abstract: Cysteine proteases are involved in many physiological processes and their hyperactivity may lead to severe diseases. Nature has developed various strategies to protect cells and whole organisms against undesired proteolysis. One of them is the control of proteolytic activity by inhibition. This paper presents the mechanisms underlying the action of proteinaceous inhibitors of cysteine proteinases and covers propeptides binding backwards relative to the substrate or distorting the protease catalytic centre similarly to serpins, the p35 protein binding covalently to the enzyme, and cystatins that are exosite binding inhibitors. The paper also discusses tyropins and chagasins that, although unrelated to cystatins, inhibit cysteine proteinases by a similar mechanism, as well as inhibitors of the apoptosis protein family that bind in a direction opposite to that of the substrate, similarly to profragments. Special attention is given to staphostatins, a novel family of inhibitors acting in an unusual manner.
authors.affiliation: Department of Analytical Biochemistry, Faculty of Biotechnology, Jagiellonian University, Kraków, Poland.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Rzychon
authors.forename: Dorota
authors.initials: D
authors.lastname: Chmiel
authors.forename: Justyna
authors.initials: J
authors.lastname: Stec-Niemczyk
mesh_terms: D015891:Cystatins / Q000502:physiology; D015853:Cysteine Proteinase Inhibitors / Q000378:metabolism*; D008956:Models, Chemical; D011487:Protein Conformation; D015843:Serpins / Q000502:physiology
chemical_list: D015891:Cystatins; D015853:Cysteine Proteinase Inhibitors; D015843:Serpins