Bak BH3 – Cancer Peptides

The Bak BH3 peptide is derived from the pro-apoptotic proteins BAK and BH3, which are both members of the BCL-2 family proteins. It can bind to Bcl-xL, antagonize its anti-apoptotic function, and rapidly induce apoptosis.The process of apoptosis can be activated by the intrinsic or extrinsic pathways, the former is activated by stress stimuli such as DNA damage and nutrient deficiency, while the latter is induced through activation of the death receptors FAS and TRAIL.
The BCL-2 family’s transmembrane anchor at the C-terminus allows them to locate at the mitochondrial outer membrane and play a vital role in apoptosis.
Within the mitochondria BH3 molecules, containing the members BID, BIM, PUMA and NOXA, can be activated by the intrinsic pathway. These in turn can initiate the homo-oligomerisation of BAX and BAK which induce mitochondrial outer membrane permeabilisation (MOMP) and the release of cytochrome c into the cytosol. Here cytochrome c associates with APAF-1 and dATP, ultimately activating effector caspase3/7 and apoptosis.