MASP-1 and MASP-2 do not activate pro-FD in resting human blood, while MASP-3 is a potential activator: kinetic analysis involving specific MASP-1 and MASP-2 inhibitors Gábor Oroszlán *, Elod Kortvely †, Dávid Szakács ‡, Andrea Kocsis *, Sascha Dammeier §, Anne Zeck ¶, Marius Ueffing †,§, Péter Závodszky *, Gábor Pál ‡ , Péter Gál *2, József Dobó *2 * Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok krt. 2, H-1117, Budapest, Hungary † Institute for Ophthalmic Research, University of Tübingen, Röntgenweg 11, 72076 Tübingen, Germany ‡ Department of Biochemistry, Eötvös Loránd University, 1/C Pázmány Péter street, H-1117, Budapest, Hungary § Institute for Ophthalmic Research, Medical Proteome Center, University of Tübingen, Nägelestrasse 5, 72074 Tübingen, Germany ¶ Natural and Medical Sciences Institute at the University of Tübingen, Department of Bioanalytics, Markwiesenstrasse 55, 72770 Reutlingen, Germany 2 Address correspondence and reprint request to J. Dobó, and/or P. Gál, Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok krt. 2, H- 1117, Budapest, Hungary, e-mail:
[email protected] (J.D.), or
[email protected] (P.G.), phone: +36-1-3826768, fax: +36-1-3826295 Running title: Kinetics of pro-FD activation Keywords (not in the title): lectin pathway; innate immunity; mannan-binding lectin; MBL- associated serine protease; thrombin; trypsin 1 Abstract 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 MASP-1/3(-/-) mice contains pro-FD and has markedly reduced alternative pathway activity.