Conversion of C2 into C2a and C2b

Stable Identifier
Reaction [transition]
Homo sapiens
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C2 is cleaved into the large C2a and the small C2b fragment. This irreversible, extracellular reaction can be catalyzed by activated MBL, generated through the lectin pathway of complement activation (Vorup-Jensen et al. 2000), and by activated C1, generated through the classical pathway (Nasagawa and Stroud 1977). N.B. Early literature refers to the larger fragment of C2 as C2a. However, complement scientists decided that the smaller of all C fragments should be designated with an 'a', the larger with a 'b', changing the nomenclature for C2. For this reason recent literature may refer to the larger C2 fragment as C2b, and the classical C3 convertase as C4bC2b. Throughout this pathway, Reactome uses the current (Feb 2012) Uniprot names which adhere to the original naming practice.
Literature References
PubMed ID Title Journal Year
10925294 Distinct pathways of mannan-binding lectin (MBL)- and C1-complex autoactivation revealed by reconstitution of MBL with recombinant MBL-associated serine protease-2

Petersen, SV, Davis, SJ, Sim, RB, Schwaeble, W, Jensenius, JC, Thiel, S, Poulsen, K, Reid, KB, Hansen, AG, Vorup-Jensen, T

J Immunol 2000
6019133 Formation and functional significance of a molecular complex derived from the second and the fourth component of human complement

Calcott, MA, Polley, MJ, Muller-Eberhard, HJ

J Exp Med 1967
70787 Cleavage of C2 by C1s into the antigenically distinct fragments C2a and C2b: demonstration of binding of C2b to C4b

Stroud, RM, Nagasawa, S

Proc Natl Acad Sci U S A 1977
12396008 The biological functions of MBL-associated serine proteases (MASPs)

Sim, RB, Moffatt, BE, Gal, P, Hajela, S, Hajela, K, Wong, KH, Ferluga, J, Kojima, M, Ambrus, G

Immunobiology 2002
Catalyst Activity

serine-type endopeptidase activity of C4 activators [plasma membrane]

Orthologous Events
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