Entry
Name
complement factor I;
complement component C3b inactivator;
C3b inactivator;
C3b/C4b inactivator;
C3bINA;
complement C3b/C4b inactivator;
complement C4b inactivator;
conglutinogen-activating factor C;
complement C3b inactivator;
factor I;
complement C4bi
Class
Hydrolases;
Acting on peptide bonds (peptidases);
Serine endopeptidases
BRITE hierarchy
Reaction(IUBMB)
Inactivates complement subcomponents C3b, iC3b and C4b by proteolytic cleavage
Comment
Cleavage of complement subcomponent C3b requires its binding to cofactor factor H or complement receptor CR1; cleavage of iC3b requires complement receptor CR1; cleavage of C4b requires C4b-binding protein. In peptidase family S1 (trypsin family)
History
EC 3.4.21.45 created 1981
Orthology
Genes
ACS : 100555342(cfi) 100563609
ASAO : 132776922(CFI) 132776925
HCG : 128327180(CFI) 128327836
GJA : 107118175 107123133(CFI)
XLA : 379108(cfi.S) 399318(cfi.L)
CCAR : 109057532 109061380
CAUA : 113041663 113065792 113065803
CGIB : 127944970 128011421
OMC : 131531652(cfi) 131531679
MASI : 127419457 127420276
MANU : 129430523 129430524
CMAO : 118822108(cfi) 118822924
CHAR : 105891454 105891456
TFS : 130521103 130523052(cfi)
PLEP : 121962086 121962091
AFB : 129093780 129093781(cfi)
SCHU : 122870131 122870134
PPRL : 129351399 129376537
SSEN : 122761302 122766591
HHIP : 117751928 117752171
HSP : 118102985 124851379 124851380
LCF : 108892255 108892267(cfi)
SLAL : 111661054 111661063
XGL : 120797247(cfi) 120797253
CCLU : 121554603 121554604
» show all
Taxonomy
Reference
Authors
Nagasawa S, Ichihara C, Stroud RM.
Title
Cleavage of C4b by C3b inactivator: production of a nicked form of C4b, C4b', as an intermediate cleavage product of C4b by C3b inactivator.
Journal
J Immunol 125:578-82 (1980)
Reference
Authors
Crossley LG.
Title
C3b inactivator and beta 1H.
Journal
Methods Enzymol 80 Pt C:112-24 (1981)
Reference
Authors
Muller-Eberhard HJ.
Title
Molecular organization and function of the complement system.
Journal
Other DBs
ExPASy - ENZYME nomenclature database: 3.4.21.45