title: Rationale for Bcl-xL/Bad peptide complex formation from structure, mutagenesis, and biophysical studies.
abstract: The three-dimensional structure of the anti-apoptotic protein Bcl-xL complexed to a 25-residue peptide from the death promoting region of Bad was determined using NMR spectroscopy. Although the overall structure is similar to Bcl-xL bound to a 16-residue peptide from the Bak protein (Sattler et al., 1997), the Bad peptide forms additional interactions with Bcl-xL. However, based upon site-directed mutagenesis experiments, these additional contacts do not account for the increased affinity of the Bad 25-mer for Bcl-xL compared to the Bad 16-mer. Rather, the increased helix propensity of the Bad 25-mer is primarily responsible for its greater affinity for Bcl-xL. Based on this observation, a pair of 16-residue peptides were designed and synthesized that were predicted to have a high helix propensity while maintaining the interactions important for complexation with Bcl-xL. Both peptides showed an increase in helix propensity compared to the wild-type and exhibited an enhanced affinity for Bcl-xL.
authors.affiliation: Pharmaceutical Discovery Division, Abbott Laboratories, Abbott Park, Illinois 60064-6098, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Petros
authors.forename: D G
authors.initials: DG
authors.lastname: Nettesheim
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: E T
authors.initials: ET
authors.lastname: Olejniczak
authors.forename: R P
authors.initials: RP
authors.lastname: Meadows
authors.forename: J
authors.initials: J
authors.lastname: Mack
authors.forename: K
authors.initials: K
authors.lastname: Swift
authors.forename: E D
authors.initials: ED
authors.lastname: Matayoshi
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: C B
authors.initials: CB
authors.lastname: Thompson
authors.forename: S W
authors.initials: SW
authors.lastname: Fesik
mesh_terms: D000595:Amino Acid Sequence; D017209:Apoptosis; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism; D011485:Protein Binding; D015202:Protein Engineering; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000737:chemistry* / Q000378:metabolism; D013329:Structure-Activity Relationship; D051025:bcl-Associated Death Protein; D051020:bcl-X Protein
chemical_list: C494819:BAD protein, human; C494811:BCL2L1 protein, human; D002352:Carrier Proteins; D010455:Peptides; D019253:Proto-Oncogene Proteins c-bcl-2; D051025:bcl-Associated Death Protein; D051020:bcl-X Protein