Complement Component C5 Convertase (C5 convertase)

Molecular Classification

Enzyme, Serine protease, Multi-subunit enzyme complex

Other Names

C4b2a3b, C4b2b3b, C3bBbC3b, C4b2aoxy3b, C4b2boxy3b, CVFBb, Classical Pathway C5 Convertase, Alternative Pathway C5 Convertase, Fluid Phase Classical Pathway C5 Convertase, Cobra Venom Factor-Dependent C5 Convertase

Disease Roles

InfectionInflammationAutoimmune diseases

Complement Component C5 Convertase Overview

Complement component C5 convertase is a crucial enzyme complex in the complement system that cleaves C5 into C5a and C5b. This cleavage is a critical step in innate immunity, leading to inflammation via C5a and the formation of the membrane attack complex (MAC) via C5b, resulting in pathogen lysis. The enzyme exists in different forms depending on the activation pathway (classical, alternative, or lectin) and its activity is tightly regulated to prevent excessive inflammation.

Mechanism of Action

Cleaves complement protein C5 into C5a and C5b, initiating downstream immune responses.

Biological Functions

Complement activation

Innate immunity

Inflammation

Pathogen lysis

Chemotaxis

Anaphylaxis

Disease Associations

Infection

Inflammation

Autoimmune diseases

Sepsis

Safety Considerations

Uncontrolled complement activation leading to inflammation and tissue damage
Increased susceptibility to infection if excessively inhibited