Biophysical characterization of,Pro-apoptotic BimBH3 peptides reveals an unexpected capacity for self-association
- Assafa, TE; Nandi, S; Smilowicz, D; Galazzo, L; Teucher, M; Elsner, C; Putz, S; Bleicken, S; Robin, AY; Westphal, D; Uson, I; Stoll, R; Czabotar, PE; Metzler-Nolte, N; Bordignon, E;
- Journal Title
- Publication Type
- Journal epub ahead of print
- Bcl-2 proteins orchestrate the mitochondrial pathway of apoptosis, pivotal for cell death. Yet, the structural details of the conformational changes of pro- and antiapoptotic proteins and their interactions remain unclear. Pulse dipolar spectroscopy (double electron-electron resonance [DEER], also known as PELDOR) in combination with spin-labeled apoptotic Bcl-2 proteins unveils conformational changes and interactions of each protein player via detection of intra- and inter-protein distances. Here, we present the synthesis and characterization of pro-apoptotic BimBH3 peptides of different lengths carrying cysteines for labeling with nitroxide or gadolinium spin probes. We show by DEER that the length of the peptides modulates their homo-interactions in the absence of other Bcl-2 proteins and solve by X-ray crystallography the structure of a BimBH3 tetramer, revealing the molecular details of the inter-peptide interactions. Finally, we prove that using orthogonal labels and three-channel DEER we can disentangle the Bim-Bim, Bcl-xL-Bcl-xL, and Bim-Bcl-xL interactions in a simplified interactome.
- Cell Press
- WEHI Research Division(s)
- Structural Biology
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Creation Date: 2020-10-02 02:01:47Last Modified: 2020-10-02 02:05:31