Caspases belong to the family of cysteine proteases that can be further sub-grouped into the initiator-executioner and proinflammatory caspases. So far ten human caspases have been reported in scientific literature: initiator caspase-2, -8, -9, -12; effector caspase-3, -6, -7; and proinflammatory caspase-1, -4, -5. All caspases are synthesized as catalytically inactive zymogens and become functional after cleavage at specific internal Asp residue and have characteristic cleavage signature xxx-xxx-xxx-Asp. Thus, caspase-3 has N-terminal prodomain (1-28 residues), large 17kD and small 12kD subunits. It also contains internal Asp-Asp-Asp sequence that blocks access to its Ile-Glu-Thr-Asp175 proteolysis site. The site is cleaved under acidic conditions by caspase-9 via direct proteolysis, than cleaved parts form heterodimer, and final step in apoptosis is initiated. Elevated levels of procaspase-3 were observed in certain cancer cells. This suggests that activation mechanism of caspase-3 may be important in cancer therapy.
Applications:
Suitable for use in ELISA and Western Blot. Other applications not tested.
Recommended Dilution:
ELISA: 1:5000-1:20,000
Western Blot: 1:500-1:1000
Optimal dilutions to be determined by the researcher.
Storage and Stability:
May be stored at 4 degrees C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Aliquots are stable for at least 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.