Activation of C1s

In this irreversible reaction, the activated C1r subunit of the C1:antibody:antigen complex cleaves the C1s subunit of the complex, activating it in turn (Ziccardi and Cooper 1976). The resulting complex is a C4 activator.

在本不可逆反应中，C1:抗体:抗原复合物中激活的C1r亚单位将复合物中的C1s亚单位切割，进而激活之（Ziccardi and Cooper 1976）。由此生成的复合物成为C4激活剂。