Detergent n-octyl-β-D-maltoside (OM) induces both monomerization and oligomerization of Bcl-w

Abstract

The process of apoptosis, programmed cell death, is principally mediated by the Bcl-2 family of proteins. Some of the Bcl-2 family members promote apoptosis, while others repress it. This protein tug-of-war commands whether the cell continues to live (anti-apoptotic) or is to die (pro-apoptotic). Bcl-w is an anti-apoptotic member of the Bcl-2 family. Bcl-w-ΔC15 (P117V), the recombinant form of the natural Bcl-w protein being studied, has 8 α-helical domains and has 178 amino acids (ΔC15). The molecular weight of Bcl-w is approximately 20 kDa and its theoretical isoelectric point (pI) is 5.82 [1]. Bcl-w is reported to dimerize naturally – i.e., without the need of inducing the dimers per se [2]. The dimers are described to form by the domain-swapping mechanism. It was also observed that the usually truncated C-terminal residues of the Bcl-w protein play a key role on Bcl-w’s biological activity [3]. As the structure of Bcl-w (and its dimerization capacity) is linked to its function, and as Bcl-w was found to be misregulated in Alzheimer’s disease [4] and other forms of neuropathy [5], it would be interesting to characterise the oligomerization properties of Bcl-w in different environments. This poster describes the progress of the research into the oligomerization characteristics of the Bcl-w protein. Samples of purified Bcl-w protein was incubated with 2% n-Octyl-β-D-maltoside (OM) detergent overnight and blue-native gel electrophoresis was run to determine the dimerization characteristics of the protein. OM was utilised to mimic the membrane environment that was reported to cause the oligomerization of other members of the Bcl-2 family of proteins [6]. [1st Award]