Description
Caspase-8 (FLICE/MACH-1) is a 55 kDa cytosolic protein with homology to the CD95/Fas-associated signal transducer, FADD/MORT-1, as well as to other caspase (ICE/Ced-3) cysteine proteases. The N-terminal region of caspase-8 contains an amino acid sequence, termed the death domain, that facilitates caspase-8-FADD direct interaction. FADD therefore acts as an adapter molecule, allowing caspase-8 to become recruited to the cytoplasmic region of Fas following receptor activation. Viral proteins (v-FLIPS) which inhibit recruitment and activation of caspase-8 have been isolated. Caspase-8 is produced as a proenzyme (55/50 kDa doublet) which upon receptor aggregation is proteolytically cleaved into smaller subunits of 40/36 (doublet), and 23 kDa. Overexpression of caspase-8 is sufficient to induce apoptosis in certain cell lines (e.g., MCF-7) and this phenotype is blocked by overexpression of the caspase-3 protease inhibitor, CrmA. The antibody recognizes both the proform of human caspase-8 (55/50 kDa doublet) as well as the cleaved forms which migrate at 40/36 (doublet) and 23 kDa in SDS/PAGE. It also immunoprecipitates the full-length human caspase-8. Full-length recombinant human caspase-8 protein was used as immunogen.
Applications include western blot analysis ( 0.125 - 0.5 µg /ml) and immunoprecipitation (4 µg /200µg cell lysate ). Jurkat T cells ( ATCC CRL-1573) are suggested as a positive control. BD Biosciences Pharmingen offers several caspase-8 antibodies. A Jurkat model cell system was used to evaluate these antibodies; these results are summarized in the following table. However, actual bands observed could vary according to the cell model system or treatment used.
The monoclonal antibody was purified from tissue culture supernatant or ascites by affinity chromatography. Store undiluted at 4°C.
1. Since applications vary, each investigator should titrate the reagent to obtain optimal results.
2. Please refer to www.bdbiosciences.com/us/s/resources for technical protocols.
3. Caution: Sodium azide yields highly toxic hydrazoic acid under acidic conditions. Dilute azide compounds in running water before discarding to avoid accumulation of potentially explosive deposits in plumbing.
