Bid BH3 peptide is a fragment derived from the BH3 domain of the pro-apoptotic protein Bid (BH3-interacting domain death agonist). Bid is a member of the BH3-only subset of the BCL-2 family of proteins that are critical control points in apoptosis and Bid is the first of the BH3 subset reported to bind and activate Bcl-2, Bax, and Bak. Bid serves as a death-inducing ligand that moves from the cytosol to the mitochondrial membrane to inactivate Bcl-2 or to activate Bax and the BH3 peptide domain, excised from the entire BH3-only molecule, can function as a specific death ligand itself
