Gosset Molecular Classification
Complement protein, Opsonin
Disease Roles
Complement Component 3b Overview
Complement component C3b is a central effector molecule of the complement system, an essential part of innate immunity. It is generated by the proteolytic cleavage of complement component 3 (C3) and functions as an opsonin, promotes convertase formation, and amplifies complement activation. C3b covalently binds to pathogen and cell surfaces, tagging them for destruction. Its activity is tightly regulated by factors such as factor H and factor I to prevent excessive complement activation and damage to host tissues.
Mechanism of Action
Inhibition of C3 convertase formation or C3b deposition; promoting C3b degradation.
Biological Functions
Opsonization
Complement activation
Immune response
Phagocytosis
Convertase formation
Amplification of complement activation
Disease Associations
Infection
Inflammation
Autoimmune diseases
Atypical hemolytic uremic syndrome (aHUS)
Age-related macular degeneration (AMD)
Glomerulonephritis
Safety Considerations
- Increased susceptibility to infection if complement activation is excessively inhibited.
- Potential for off-target effects on complement-mediated homeostasis.
Interacting Drugs
Compstatin analogs (e.g., AMY-1066)
Associated Biomarkers
| Biomarker |
|---|
| Plasma C3b levels |
| C3b deposition on cell surfaces |