Details of the Drug Therapeutic Target (DTT)

General Information of Drug Therapeutic Target (DTT) (ID: TT6ATLX)

• DTT Name: Complement factor I (CFI)
• Synonyms: IF; Complement factor I light chain; C3B/C4B inactivator
• Gene Name: CFI
• DTT Type: Literature-reported target; [1]
• BioChemical Class: Peptidase
• UniProt ID: CFAI_HUMAN
• TTD ID: T92750
• EC Number: EC 3.4.21.45
• Sequence:
  MKLLHVFLLFLCFHLRFCKVTYTSQEDLVEKKCLAKKYTHLSCDKVFCQPWQRCIEGTCV
  CKLPYQCPKNGTAVCATNRRSFPTYCQQKSLECLHPGTKFLNNGTCTAEGKFSVSLKHGN
  TDSEGIVEVKLVDQDKTMFICKSSWSMREANVACLDLGFQQGADTQRRFKLSDLSINSTE
  CLHVHCRGLETSLAECTFTKRRTMGYQDFADVVCYTQKADSPMDDFFQCVNGKYISQMKA
  CDGINDCGDQSDELCCKACQGKGFHCKSGVCIPSQYQCNGEVDCITGEDEVGCAGFASVT
  QEETEILTADMDAERRRIKSLLPKLSCGVKNRMHIRRKRIVGGKRAQLGDLPWQVAIKDA
  SGITCGGIYIGGCWILTAAHCLRASKTHRYQIWTTVVDWIHPDLKRIVIEYVDRIIFHEN
  YNAGTYQNDIALIEMKKDGNKKDCELPRSIPACVPWSPYLFQPNDTCIVSGWGREKDNER
  VFSLQWGEVKLISNCSKFYGNRFYEKEMECAGTYDGSIDACKGDSGGPLVCMDANNVTYV
  WGVVSWGENCGKPEFPGVYTKVANYFDWISYHVGRPFISQYNV
• Function: Inhibits these pathways by cleaving three peptide bonds in the alpha-chain of C3b and two bonds in the alpha-chain of C4b thereby inactivating these proteins. Essential cofactors for these reactions include factor H and C4BP in the fluid phase and membrane cofactor protein/CD46 and CR1 on cell surfaces. The presence of these cofactors on healthy cells allows degradation of deposited C3b by CFI in order to prevent undesired complement activation, while in apoptotic cells or microbes, the absence of such cofactors leads to C3b-mediated complement activation and subsequent opsonization. Trypsin-like serine protease that plays an essential role in regulating the immune response by controlling all complement pathways.
• KEGG Pathway:
  Complement and coagulation cascades (hsa04610)
  Staphylococcus aureus infection (hsa05150)
• Reactome Pathway: Regulation of Complement cascade (R-HSA-977606)

Molecular Interaction Atlas (MIA) of This DTT

1 Discontinued Drug(s) Targeting This DTT

Drug Name	Drug ID	Indication	ICD 11	Highest Status	REF
TP-20	DM5ZNSQ	Cerebrovascular ischaemia	8B1Z	Terminated	[1]

References

• [1] Endothelial targeting and enhanced antiinflammatory effects of complement inhibitors possessing sialyl Lewisx moieties. J Immunol. 1999 Apr 15;162(8):4952-9.