Here’s a table listing some key components of the human complement system, their functions, and cleavage products:
| Component | Function | Cleavage Products |
|---|---|---|
| C1q | Recognition of immune complexes | – |
| C1r | Activation of C1s | – |
| C1s | Initiates the classical pathway | – |
| C2 | Activation of C3 convertase in classical pathway | C2a, C2b |
| C3 | Opsonization, chemotaxis, inflammation | C3a, C3b |
| C4 | Activation of C3 convertase in classical pathway | C4a, C4b |
| C5 | Recruitment of neutrophils, lysis of pathogens | C5a, C5b |
| C6 | Formation of membrane attack complex (MAC) | C6a, C6b |
| C7 | Stabilization of MAC | C7a, C7b |
| C8 | Participation in MAC formation | C8a, C8b |
| C9 | Formation of membrane attack complex (MAC) | C9 |
| Factor B | Activation of C3 convertase in alternative pathway | Ba, Bb |
| Factor D | Cleavage of Factor B in alternative pathway | – |
| Properdin (Factor P) | Stabilization of C3 convertase in alternative pathway | – |
| CD46 (Membrane Cofactor Protein) | Regulation of complement activation | – |
| CD55 (Decay-Accelerating Factor) | Inhibition of complement cascade | – |
| CD59 (Protectin) | Inhibition of MAC formation | – |
Next Topic: Complement Activation Initiation: All Roads Lead to C3 Convertase
Source: ChatGPT response prompted and edited by Joel Graff.
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