EC 3.4.21.104

Reaction: Selective cleavage after Arg²²³ in complement component C2 (-Ser-Leu-Gly-ArgLys-Ile-Gln-Ile) and after Arg⁷⁶ in complement component C4 (-Gly-Leu-Gln-ArgAla-Leu-Glu-Ile)

Other name(s): MASP-2; MBP-associated serine protease-2; mannose-binding lectin-associated serine protease-2; p100; mannan-binding lectin-associated serine peptidase

Comments: Mannan-binding lectin (MBL) recognizes patterns of neutral carbohydrates, such as mannose and N-acetylglucosamine, on a wide range of microbial surfaces and is able to initiate activation of the lectin pathway of complement [7]. This enzyme displays C-like esterolytic activity (cf. EC 3.4.21.42, complement subcomponent C). It also cleaves C4 and C2 with efficiencies that are relatively higher than those of EC 3.4.21.42 [3]. Belongs in peptidase family S1A.

Links to other databases: BRENDA, EXPASY, KEGG, MEROPS, Metacyc, PDB, CAS registry number: 214915-16-9

References:

1. Matsushita, M. and Fujita, T. Activation of the classical complement pathway by mannose-binding protein in association with a novel C1s-like serine protease. J. Exp. Med. 176 (1992) 1497-1502. [PMID: 1460414]

2. Thiel, S., Vorup-Jensen, T., Stover, C.M., Schwaeble, W., Laursen, S.B., Poulsen, K., Willis, A.C., Eggleton, P., Hansen, S., Holmskov, U., Reid, K.B. and Jensenius, J.C. A second serine protease associated with mannan-binding lectin that activates complement. Nature 386 (1997) 506-510. [PMID: 9087411]

3. Rossi, V., Cseh, S., Bally, I., Thielens, N.M., Jensenius, J.C. and Arlaud, G.J. Substrate specificities of recombinant mannan-binding lectin-associated serine proteases-1 and -2. J Biol. Chem. 276 (2001) 40880-40887. [PMID: 11527969]

4. Ambrus, G., Gal, P., Kojima, M., Szilagyi, K., Balczer, J., Antal, J., Graf, L., Laich, A., Moffatt, B.E., Schwaeble, W., Sim, R.B. and Zavodszky, P. Natural substrates and inhibitors of mannan-binding lectin-associated serine protease-1 and -2: a study on recombinant catalytic fragments. J. Immunol. 170 (2003) 1374-1382. [PMID: 12538697]

5. Harmat, V., Gal, P., Kardos, J., Szilagyi, K., Ambrus, G., Vegh, B., Naray-Szabo, G. and Zavodszky, P. The structure of MBL-associated serine protease-2 reveals that identical substrate specificities of C1s and MASP-2 are realized through different sets of enzyme-substrate interactions. J. Mol. Biol. 342 (2004) 1533-1546. [PMID: 15364579]

6. Chen, C.B. and Wallis, R. Two mechanisms for mannose-binding protein modulation of the activity of its associated serine proteases. J. Biol. Chem. 279 (2004) 26058-26065. [PMID: 15060079]

7. Teillet, F., Dublet, B., Andrieu, J.P., Gaboriaud, C., Arlaud, G.J. and Thielens, N.M. The two major oligomeric forms of human mannan-binding lectin: chemical characterization, carbohydrate-binding properties, and interaction with MBL-associated serine proteases. J. Immunol. 174 (2005) 2870-2877. [PMID: 15728497]