Assessing pore formation by BCL-2 during apoptosis in cell lines and human leukemic cells: Cysteine 158 in the alpha 5 helical loop is in an aqueous environment

The ability of the Bcl-2 family of anti-apoptotic proteins to prevent programmed cell death has been attributed to multiple mechanisms, including binding pro-apoptotic proteins as well as the formation of pores. The evidence for the latter mechanism is extensive but indirect and includes the presence of alpha helical domains (designated alpha-5 and alpha6) that are similar to several bacterial pore forming domains, as determined by NMR and Xray …