C-reactive protein binds with which part of C1q?

C-reactive protein (CRP) is an acute-phase protein that plays a significant role in the immune response, particularly in the recognition and opsonization of pathogens. When CRP is present in the blood, it can bind to C1q, which is the first component of the classical complement pathway.

The interaction between CRP and C1q is primarily facilitated by the stalks of C1q. The stalks are crucial because they serve as structural linking components that help connect the globular heads of C1q to the rest of the complement system. When CRP binds to the stalks of C1q, it triggers the activation of the complement cascade, which ultimately leads to enhanced phagocytosis of pathogens and clearing of damaged cells.

Recognizing this binding specificity is important because it highlights the role that CRP plays in innate immunity by activating the complement system through its interaction with C1q. Therefore, the binding of CRP to the stalks of C1q is a key step in the regulation and enhancement of the immune response.