MASP-1 and MASP-2 Do Not Activate Pro-Factor D in Resting Human Blood, whereas MASP-3 Is a Potential Activator: Kinetic Analysis Involving Specific MASP-1 and MASP-2 Inhibitors.
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Gyűjtemény: Status = Published


Type = Article
Cím:
MASP-1 and MASP-2 Do Not Activate Pro-Factor D in Resting Human Blood, whereas MASP-3 Is a Potential Activator: Kinetic Analysis Involving Specific MASP-1 and MASP-2 Inhibitors.
Létrehozó:
Oroszlán, Gábor
Kortvely, Előd
Szakács, Dávid
Kocsis, Andera
Dammeier, Sascha
Závodszky, Péter
Pál, Gábor
Gál, Péter
DobĂł, JĂłzsef
Kiadó:
American Association of Immunologists
Dátum:
2016
Téma:
QH3011 Biochemistry / biokémia
QR180 Immunology / immunolĂłgia
Tartalmi leírás:
It had been thought that complement factor D (FD) is activated at the site of synthesis, and only FD lacking a propeptide is present in blood. The serum of mannose-binding lectin-associated serine protease (MASP)-1/3(-/-) mice contains pro-FD and has markedly reduced alternative pathway activity. It was suggested that MASP-1 and MASP-3 directly activate pro-FD; however, other experiments contradicted this view. We decided to clarify the involvement of MASPs in pro-FD activation in normal, as opposed to deficient, human plasma and serum. Human pro-FD containing an APPRGR propeptide was produced in insect cells. We measured its activation kinetics using purified active MASP-1, MASP-2, MASP-3, as well as thrombin. We found all these enzymes to be efficient activators, whereas MASP proenzymes lacked such activity. Pro-FD cleavage in serum or plasma was quantified by a novel assay using fluorescently labeled pro-FD. Labeled pro-FD was processed with t1/2s of approximately 3 and 5 h in serum and plasma, respectively, showing that proteolytic activity capable of activating pro-FD exists in blood even in the absence of active coagulation enzymes. Our previously developed selective MASP-1 and MASP-2 inhibitors did not reduce pro-FD activation at reasonable concentration. In contrast, at very high concentration, the MASP-2 inhibitor, which is also a poor MASP-3 inhibitor, slowed down the activation. When recombinant MASPs were added to plasma, only MASP-3 could reduce the half-life of pro-FD. Combining our quantitative data, MASP-1 and MASP-2 can be ruled out as direct pro-FD activators in resting blood; however, active MASP-3 is a very likely physiological activator.
Nyelv:
angol
Típus:
Article
PeerReviewed
info:eu-repo/semantics/article
Formátum:
text
Azonosító:
Oroszlán, Gábor and Kortvely, Előd and Szakács, Dávid and Kocsis, Andera and Dammeier, Sascha and Závodszky, Péter and Pál, Gábor and Gál, Péter and Dobó, József (2016) MASP-1 and MASP-2 Do Not Activate Pro-Factor D in Resting Human Blood, whereas MASP-3 Is a Potential Activator: Kinetic Analysis Involving Specific MASP-1 and MASP-2 Inhibitors. Journal of Immunology, 196. pp. 857-865. ISSN 0022-1767, ESSN: 1550-6606
Kapcsolat:
https://dx.doi.org/10.4049/jimmunol.1501717
MTMT:2990301; doi:10.4049/jimmunol.1501717