SRP0230 Sigma-Aldrich

XIAP Active human

recombinant, expressed in baculovirus infected insect cells, ≥65% (SDS-PAGE)

Synonym: Baculoviral IAP repeat-containing protein 4 (BIRC4), E3 ubiquitin-protein ligase XIAP (MIHA), IAP-like protein (ILP1), Inhibitor of apoptosis protein 3, X-linked inhibitor of apoptosis

  •  NACRES NA.32



Related Categories Apoptosis Supressor Proteins and Antibodies, Apoptosis and Cell Cycle, Cell Biology, Cell Signaling and Neuroscience, Suppressors of Apoptosis More...
biological source   human
recombinant   expressed in baculovirus infected insect cells
assay   ≥65% (SDS-PAGE)
form   aqueous solution
mol wt   57 kDa
packaging   pkg of 20 μg
storage condition   avoid repeated freeze/thaw cycles
NCBI accession no.   NM_001167
UniProt accession no.   P98170
shipped in   dry ice
storage temp.   −70°C
Gene Information   human ... XIAP(331)


General description

XIAP (X-linked inhibitor of apoptosis) is an anti-apoptotic protein belonging to the inhibitor of apoptosis protein (IAP) family, an evolutionary conserved protein family. XIAP contains three tandem copies of BIR (baculovirusIAP repeat) domain, which is composed of ∼70 residues. IAP family members also contain a RING (really interesting new gene) zinc finger domain in their C-terminals.


Useful in conjunction with E1 and E2 for the study of enzyme kinetics, screening inhibitors, and selectivity profiling.

Biochem/physiol Actions

XIAP (X-linked inhibitor of apoptosis) is the most potent caspase-interacting protein and inhibits both intrinsic and extrinsic pathways of apoptosis. Its up-regulation in tumor cells is linked with resistance to chemotherapy. In inflammatory breast cancer (IBC) this protein is linked with resistance to antibody-dependent cellular cytotoxicity (ADCC) driven by cetuximab and trastuzumab. Embelin, an inhibitor of XIAP, functions as an anti-tumor agent in myeloma cell line (HL-60) by suppressing the expression of XIAP. Elevated expression of XIAP in rectal cancer is associated with chemotherapy resistance.

Unit Definition

One unit is defined as the amount of enzyme required to transfer 1 pmol of ubiquitin to substrate/min at 37°C.

Physical form

Formulated in 25 mM Tris-HCl, pH 8.0, 100 mM NaCl, 0.05% Tween-20, 100 μg/ml FLAG peptide, 20% glycerol, and 3 mM DTT.

Preparation Note

Thaw on ice. Upon first thaw, briefly spin tube containing enzyme to recover full content of the tube. Aliquot enzyme into single use aliquots. Store remaining undiluted enzyme in aliquots at -70°C. Note: Enzyme is very sensitive to freeze/thaw cycles.

Safety & Documentation

Safety Information

Safety Information for this product is unavailable at this time.


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