Protease inhibitors serpin

Cl-Inh belongs to a superfamily of serine protease inhibitors (serpins) and is a major inhibitor of F-XIIa and kallikrein. It is also an inhibitor of activated complement factors C1 q, C1 r, and C1 s. C1 -Inh thus regulates the activation of two important plasma cascade systems. Proteases induce a conformational change in the plasma protein a2-M, which results in entrapment of the protease into the a2-M cage (B4). In vivo, a2-M acts as a second inhibitor of kallikrein. 

The observation that serine protease inhibitors (serpins) can block several forms of apoptosis (Higuchi et al, 1995, Nicholson etal 1995, Martin et al, 1996, Lahti et al, 1996 Dubrez et al, 1996) has led to the central... 

Active site amino acid sequence of selected serine protease inhibitors (serpins) and their sensitivity... 

The sensitivity of many serine-protease inhibitors (serpins) to ROIs has been determined in a number of groups and is summarized in Table 2. Of these serine-protease inhibitors, the most sensitive to inactivation by oxidants like OC1- or chloramines are those which contain methionine at or juxtaposed to the reactive centre [49] (e.g. plasminogen activator-inhibitor-1 (PAI-1), oq-proteinase inhibitor and 0(2-antiplasmin). Inactivation is thought to principally be due to the oxidation of these methionine residues to methionine sulfoxide [50-52]. PAI-1, which is rapidly inactivated in plasma, is also extremely sensitive to oxidants like iV-chlorosuccinimide, chloramine-T and H2O2, through a reaction involving oxidation of the reactive-site methionine. 

Antithrombin. A serine protease inhibitor (serpin) that degrades the serine proteases of thrombin, factors IXa, Xa, XIa and Xlla. It is constantly active, but its adhesion to these factors is increased by the presence of heparin sulphate (a glycosaminoglycan) or the administration of heparins (different heparinoids increase affinity to factor Xa, thrombin, or both). Deficiency of antithrombin (inborn or acquired, e.g. in proteinuria) leads to thrombophilia. 

The baculoviral protein p35 blocks apoptosis in insect cells and in neurons, but the site of action of this protein is not known (Clem et al., 1991 Rabi-zadeh et al., 1993a Martinou et al., 1995). The cowpox viral gene crmA (cytokine response modifier gene A) encodes a serine protease inhibitor (SERPIN)-like protein that is a specific inhibitor of ICE (Ray et al., 1992 Komiyama et al., 1994). CrmA protein inhibits the activity of ICE and the production of mature IL-ly3, thereby suppressing immune responses to infection (Ray et al., 1992 Komiyama et al., 1994). Microinjection of CrmA protein into cells prevents cell death in a number of systems including Fas-induced apoptosis (Enarl et al., 1995 Los et al., 1995 Tewari and Dixit ... 

LG. Winkler, J. Hendy, P. Coughlin, A. Horvath, and J. P. Levesque, Serine protease inhibitors serpinal and serpinaS are down-regulated in bone marrow during hematopoietic progenitor mobilization,/. Exp. Med., 201 (2005) 1077-1088. 

Imamura S, Namangala B, Tajima T et al. Two serine protease inhibitors (serpins) that induce a bovine protective immune response against Rhipicephalus appendiculatns ticks. Vaccine 2006 24(13) 2230-2237. 

Imamura S, da Silva Vaz Junior I, Sugino M et al. A serine protease inhibitor (serpin) from haemaphysalis longicornis as an antitick vaccine. Vaccine 2005 23(10) 1301-1311. 

Serine Protease Inhibitors/Serpins Serpin Structure and Function... 

Munuswamy Ramunujam G, Lucas A. Mammahan serine protease inhibitor (serpin). ncucoseriMn, targets thrombolytic proteases to reduce inflammation, atherogenesis and T helper lymphocyte activation. Poster. American Heart Association. Orlando, FL 2007... 

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