Activation of C1r

Stable Identifier
R-HSA-173626
Type
Reaction [transition]
Species
Homo sapiens
Compartment
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C1 activation requires interaction with two separate Fc domains, so pentavalent IgM antibody is far more efficient at complement activation than IgG antibody (Muller-Eberhard and Kunkel 1961). Antibody binding results in a conformational change in the C1r component of the C1 complex and a proteolytic cleavage of C1r, activating it (Ziccardi and Cooper 1976). This reaction is irreversible under physiological conditions.

Literature References
PubMed ID Title Journal Year
1249422 Activation of C1r by proteolytic cleavage

Ziccardi, RJ, Cooper, NR

J Immunol 1976
Participants
Participant Of
Catalyst Activity
Catalyst Activity
Title
serine-type endopeptidase activity of Antigen:IgG:C1Q:2xC1R:2xC1S [plasma membrane]
Physical Entity
Activity
This event is regulated
Orthologous Events
Authored
Reviewed
Created