Differential substrate and inhibitor profiles for human MASP-1 and MASP-2

Presanis, Julia S.; Hajela, Krishnan; Ambrus, Géza; Gál, Péter; Sim, Robert B.

doi:10.1016/j.molimm.2003.10.013

Cited by 131 publications

(112 citation statements)

References 37 publications

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“…1). AT is known to interact with MASP-1, and the affinity is increased by heparin (31,32). Therefore, we measured MASP-1/AT complexes and found elevated levels in heparinized plasma compared with the other plasma types (Supplemental Fig.…”

Section: Establishing a Masp-1/c1-inh Assaymentioning

confidence: 91%

The Levels of the Lectin Pathway Serine Protease MASP-1 and Its Complex Formation with C1 Inhibitor Are Linked to the Severity of Hereditary Angioedema

Hansen

Csuka

Munthe-Fog

et al. 2015

The Journal of Immunology

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C1 inhibitor (C1-INH) is known to form complexes with the lectin complement pathway serine proteases MASP-1 and MASP-2. Deficiency of C1-INH is associated with hereditary angioedema (HAE), an autosomal inherited disease characterized by swelling attacks caused by elevated levels of bradykinin. MASP-1 was shown to cleave high m.w. kininogen into bradykinin; therefore, we hypothesized that MASP-1 levels and the quantity of MASP-1/C1-INH complexes might be associated with different paraclinical and clinical outcomes of HAE. We measured MASP-1 serum concentrations and endogenous MASP-1/C1-INH complex levels in 128 HAE patients and 100 controls. Relatively high levels of pre-existing MASP-1/C1-INH complexes were observed in normal serum, and we found that both the serum levels of MASP-1 and the complex formation between MASP-1 and C1-INH were significantly reduced in HAE patients compared with matched controls (p < 0.0001). The level of MASP-1 and MASP-1/C1-INH complexes in HE patients correlated with the level of C1-INH (p = 0.0009 and p = 0.0047, respectively), the level of C4 (p = 0.0084 and p < 0.0001, respectively), and the number of attacks in the year of blood sampling (p = 0.0075 and p = 0.0058, respectively). In conclusion, we show that MASP-1/C1-INH complexes circulate in normal human blood. The levels of MASP-1 and MASP-1/C1-INH complexes are reduced in HAE patients compared with controls. Both MASP-1 and MASP-1/C1-INH complexes are related to the degree of complement C4 consumption, as well as the severity of disease. These results suggest that MASP-1 may exert a previously unrecognized role in the pathophysiology of HAE.

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Section: Establishing a Masp-1/c1-inh Assaymentioning

confidence: 91%

The Levels of the Lectin Pathway Serine Protease MASP-1 and Its Complex Formation with C1 Inhibitor Are Linked to the Severity of Hereditary Angioedema

Hansen

Csuka

Munthe-Fog

et al. 2015

The Journal of Immunology

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“…SGMI-2 was dissolved in water at a concentration of 2.83 mg/ml (706 µM) and used in the thrombelastographic experiments at a final concentration of 5 µmol/l. Hirudin (Novartis, Basel, Switzerland) specifically binds to the active site and exosite 1 of thrombin species and does not interfere with MASP-1 activity (Parry et al, 1993;Presanis et al, 2003). Hirudin was used in prothrombin cleavage experiments at a final concentration of 600 units/ml.…”

Section: Specific Protease Inhibitorsmentioning

confidence: 99%

MASP-1 of the complement system promotes clotting via prothrombin activation

Jenny

Dobó

Gál

et al. 2015

Molecular Immunology

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associated serine protease; MBL, mannose binding lectin; MCF, maximum clot firmness; MES, 2-(N-Morpholino)-ethanesulfonic acid; PAR4, protease activated receptor 4; PPP, platelet-poor plasma; PT-DP, Prothrombin-depleted plasma; PVDF, polyvinylidene difluoride; rMASP-1cf, MASP-1 catalytic fragment; SGMI, Schistocerca gregaria protease inhibitor (SGPI)-based MASPinhibitor; WB, whole blood. AbstractMannan-binding lectin-associated serine protease-1 (MASP-1), a protein of the complement lectin pathway, resembles thrombin in terms of structural features and substrate specificity, and it has been shown to activate coagulation factors. Here we studied the effects of MASP-1 on clot formation in whole blood (WB) and platelet-poor plasma (PPP) by thrombelastography and further elucidated the underlying mechanism. Cleavage of prothrombin by MASP-1 was investigated by SDS-PAGE and N-terminal sequencing of cleavage products. Addition of MASP-1 or thrombin to WB and PPP shortened the clotting time and clot formation time significantly compared to recalcified-only samples. The combination of MASP-1 and thrombin had additive effects. In a purified system, MASP-1 was able to induce clotting only in presence of prothrombin. Analysis of MASP-1-digested prothrombin confirmed that MASP-1 cleaves prothrombin at three cleavage sites. In conclusion, we have shown that MASP-1 is able to induce and promote clot formation measured in a global setting using the technique of thrombelastography. We further confirmed that MASP-1-induced clotting is dependent on prothrombin. Finally, we have demonstrated that MASP-1 cleaves prothrombin and identified its cleavage sites, suggesting that MASP-1 gives rise to an alternative active form of thrombin by cleaving at the cleavage site R393.

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“…C1s activity was measured using the same chromogenic substrate as used for MASP-2 activity. Proteolytic activity of MASP-1 was measured using a modified protocol of Presanis et al [24] All incubations were performed in 100 μL volume, all washes were done with water. Briefly, Nunc Maxisorp microtiter plates (Invitrogen, Breda, the Netherlands) were coated with mannan (50 μg/mL in 0.1 M carbonate buffer, pH 9.6).…”

Section: Fluorogenic and Chromogenic Assays For Masp-2 Masp-1 And C1smentioning

confidence: 99%

TFPI inhibits lectin pathway of complement activation by direct interaction with MASP‐2

et al. 2014

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The lectin pathway (LP) of complement has a protective function against invading pathogens. Recent studies have also shown that the LP plays an important role in ischemia/reperfusion (I/R)-injury. MBL-associated serine protease (MASP)-2 appears to be crucial in this process. The serpin C1-inhibitor is the major inhibitor of MASP-2. In addition, aprotinin, a Kunitz-type inhibitor, was shown to inhibit MASP-2 activity in vitro.In this study we investigated whether the Kunitz-type inhibitor tissue factor pathway inhibitor (TFPI) is also able to inhibit MASP-2. Ex vivo LP was induced and detected by C4-deposition on mannan-coated plates. The MASP-2 activity was measured in a fluid-phase chromogenic assay. rTFPI in the absence or presence of specific monoclonal antibodies was used to investigate which TFPI-domains contribute to MASP-2 inhibition. Here, we identify TFPI as a novel selective inhibitor of MASP-2, without affecting MASP-1 or the classical pathway proteases C1s and C1r. Kunitz-2 domain of TFPI is required for the inhibition of MASP-2. Considering the role of MASP-2 in complement-mediated I/R-injury, the inhibition of this protease by TFPI could be an interesting therapeutic approach to limit the tissue damage in conditions such as cerebral stroke, myocardial infarction or solid organ transplantation.Keywords: Complement-coagulation crosstalk r Complement inhibition r MASP-2 r TFPI Additional supporting information may be found in the online version of this article at the publisher's web-site IntroductionThe complement system comprises over 30 different plasma proteins. The complement system consists of three activation pathways, each differing in their recognition mechanism while Correspondence: Mischa P. Keizer e-mail: m.keizer@sanquin.nl converging in a common terminal pathway at the level of complement component 3 (C3). The antibody-dependent classical pathway (CP) initiates the complement system via the binding of C1q to antibodies. Binding to specific sugar motifs by mannan-binding lectins (MBLs) or one of the ficolins activates the lectin pathway (LP) by subsequent activation of the MBL-associated serine proteases (MASPs). The alternative pathway activates spontaneously on surfaces that lack complement regulatory proteins and acts as amplification route for the other two pathways.www.eji-journal.eu Eur. J. Immunol. 2015. 45: 544-550 Innate immunity 545Besides the LP role as first line of defense against invading pathogens, by opsonization and induction of an inflammatory response, recent studies have shown that the LP also plays a prominent role in ischemia/reperfusion (I/R) injury. MBL-deficiency appears to be protective in human myocardial infarction [1], gastrointestinal I/R injury [1], and stroke [2]. This detrimental role of the LP in I/R injury has been confirmed in mice by selectively targeting MASP-2. MASP-2 knockout mice were protected from both gastrointestinal and myocardial I/R injury [3]. Together, these data indicate an important role for MASP-2 in aggravating cell damage in ischemi...

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Differential substrate and inhibitor profiles for human MASP-1 and MASP-2

Cited by 131 publications

References 37 publications

The Levels of the Lectin Pathway Serine Protease MASP-1 and Its Complex Formation with C1 Inhibitor Are Linked to the Severity of Hereditary Angioedema

The Levels of the Lectin Pathway Serine Protease MASP-1 and Its Complex Formation with C1 Inhibitor Are Linked to the Severity of Hereditary Angioedema

MASP-1 of the complement system promotes clotting via prothrombin activation

TFPI inhibits lectin pathway of complement activation by direct interaction with MASP‐2

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