complement C4b

Distinguished from C4B = C4F one of 2 forms of intact C4. In association with C1s, activates C2.

General

complement-activating enzyme complement-4 (C4)

Properties

SIZE: MW = 193 kD entity length = 1744 aa COMPARTMENT: membrane STATE: active state MOTIF: N-glycosylation site {N226} cysteine residue {C702} MODIFICATION: cysteine residue {C728} cysteine residue {C703} MODIFICATION: cysteine residue {C735} cysteine residue {C716} MODIFICATION: cysteine residue {C736} cysteine residue {C728} MODIFICATION: cysteine residue {C702} cysteine residue {C735} MODIFICATION: cysteine residue {C703} cysteine residue {C736} MODIFICATION: cysteine residue {C716} N-glycosylation site {N862} active site allosteric site FOR-BINDING-OF: complement C4b-binding protein N-glycosylation site {N1328} N-glycosylation site {N1391} sulfotyrosine site {Y1417} MODIFICATION: sulfate sulfotyrosine site {Y1420} MODIFICATION: sulfate sulfotyrosine site {Y1422} MODIFICATION: sulfate

References

Clinical Diagnosis and Management by Laboratory Methods, 18th ed, J.B. Henry (ed), W.B. Saunders, Philadelphia, PA, 1991 pg 832