When immune complex (IC) binds to Clq, C1INH is detached form Clr, and then the serine protease is activated, and thenthe complement classical pathway is activated.

• 在一般情况下，C1r与C1INH(C1 inhibitor)结合着，而一旦有免疫复合物(IC)结合到C1q上时，浙江大学硕士学位论文CllNH的抑制作用即行移除，Clr的构象发生改变，具有酶活性，从而启动补体激活经典途径。