Conformation of membrane-associated proapoptotic tBid.

ABSTRACT: The proapoptotic Bcl-2 family protein Bid is cleaved by caspase-8 to release the C-terminal fragment tBid, which translocates to the outer mitochondrial membrane and induces massive cytochrome c release and cell death. In this study, we have characterized the conformation of tBid in lipid membrane environments, using NMR and CD spectroscopy with lipid micelle and lipid bilayer samples. In micelles, tBid adopts a unique helical conformation, and the solution NMR (1)H/(15)N HSQC spectra have a single well resolved resonance for each of the protein amide sites. In lipid bilayers, tBid associates with the membrane with its helices parallel to the membrane surface and without trans-membrane helix insertion, and the solid-state NMR (1)H/(15)N polarization inversion with spin exchange at the magi

SUBMITTER: Gong XM 

PROVIDER: S-EPMC3033194 | biostudies-literature | 2004 Jul

REPOSITORIES: biostudies-literature