CAST Rabbit pAb for WB, ELISA - P20810

Core Product Specifications and Parameters

Biological Background: Calpastatin Function and Localization

• Calpastatin (CAST) is a specific endogenous inhibitor of calpain, a family of calcium-dependent cysteine proteases (EC 3.4.22.-) involved in cytoskeletal remodeling, signal transduction, and apoptosis.
• By tightly binding and inhibiting calpain, calpastatin regulates protease activity in muscle tissue, playing a critical role in postmortem meat tenderization and possibly in the control of muscle protein degradation in living cells.
• The CAST gene undergoes extensive alternative splicing, generating multiple isoforms with distinct tissue distributions and inhibitory capacities.
• Calpastatin contains four repetitive inhibitory domains (L-domains), each capable of independently inhibiting calpain, along with an N-terminal domain L and a C-terminal tail; this multi-repeat architecture underlies its potent and cooperative protease inhibition.
• Post-translational modifications include acetylation, phosphorylation, ubiquitination, and isopeptide bond formation, which may modulate protein stability, localization, and inhibitory efficiency.
• Expression of calpastatin is detected in a wide range of tissues, with a characterized presence in sperm (as the BS-17 component) and disease association with palmoplantar keratoderma.

Experimental Guidance and Technical Tips

• The immunogen is a synthetic peptide spanning amino acids 510–610 of human CAST; antibody reactivity may be influenced by isoform usage or post-translational modifications in this region.
• For Western blot, consider optimizing primary antibody concentration (e.g., 1:500–1:2000) and using appropriate positive controls such as HeLa, HEK293, or skeletal muscle lysates, where calpastatin is endogenously expressed.
• The antibody is cross-reactive with mouse and rat; verify band patterns in these species, as molecular weights may slightly differ due to isoform variation.
• For ELISA, titrate the antibody against the immunogen peptide or full-length recombinant protein to establish working concentrations; use appropriate blocking and washing steps to reduce background.
• Because this is a polyclonal antibody, it may detect multiple calpastatin isoforms; confirm specificity through siRNA knockdown or overexpression experiments in relevant cell models.

CamelBio: Your One-Stop Sourcing Bridge

CamelBio supports diagnostic manufacturers, labs, and research institutes with one-stop access to validated IVD raw materials, streamlining development from concept to clinic. For calpastatin research, we offer rabbit polyclonal antibodies like this CAST Rabbit pAb, along with matched antigen pairs, recombinant proteins, and bulk ancillary reagents. Contact our team to source customized monoclonal/polyclonal antibodies, difficult-to-find protease-inhibitor targets, or complete immunoassay development kits.