C3 convertase can form via three pathways: the classical pathway, the lectin pathway, and the alternative pathway. Each pathway involves a different set of proteins and mechanisms for activation.
- In the classical pathway, C3 convertase is formed by the combination of C4b and C2a. - In the lectin pathway, it is similarly formed by the binding of lectin to pathogen surfaces, leading to the formation of C4bC2a. - In the alternative pathway, C3 convertase is formed by the combination of C3b and Bb, stabilized by properdin.
