Factor I inactivates Factor H-boundC3b

Stable Identifier
R-HSA-977371
Type
Reaction [transition]
Species
Homo sapiens
Compartment
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Following the displacement of Bb from C3bBb, Factor I (CFI) cleaves Factor H-bound C3b producing iC3b, which remains bound to the membrane. The majority of the C3b alpha chain is retained as two fragments which are tethered to the beta chain by disulphide bonds. iC3b is proteolytically inactive and cannot contribute to the complement cascade process, though it still contributes to opsonization.

Literature References
PubMed ID Title Journal Year
6219696 Kinetic and thermodynamic analysis of the control of C3b by the complement regulatory proteins factors H and I

Pangburn, MK, Muller-Eberhard, HJ

Biochemistry 1983
3848661 C3 nephritic factor protects bound C3bBb from cleavage by factor I and human erythrocytes

Mold, C, Medof, ME

Mol Immunol 1985
Participants
Participant Of
Catalyst Activity
Catalyst Activity
Title
serine-type endopeptidase activity of CFI:CFH,FHR3:C3b [plasma membrane]
Physical Entity
Activity
Orthologous Events
Authored
Reviewed
Created