A protein-containing complex composed of six subunits of each of the three homologous polypeptide chains C1QA, C1QB, and C1QB. It is a subunit of the complement C1 complex. In addition to complement activation, C1q appears to have roles in homeostasis and cellular development, superoxide (O2-) production by neutrophils, blood coagulation and neurological synapse pruning.
Complement 1q