In silico and in vitro elucidation of BH3 binding specificity toward Bcl-2.

TitleIn silico and in vitro elucidation of BH3 binding specificity toward Bcl-2.
Publication TypeJournal Article
Year of Publication2012
AuthorsLondon N, Gullá S, Keating AE, Schueler-Furman O
Date Publishedjul
KeywordsAmino Acid Sequence, Animals, Apoptosis Regulatory Proteins, Apoptosis Regulatory Proteins: chemistry, Apoptosis Regulatory Proteins: metabolism, bcl-X Protein, bcl-X Protein: chemistry, bcl-X Protein: metabolism, Humans, Membrane Proteins, Membrane Proteins: chemistry, Membrane Proteins: metabolism, Models, Molecular, Molecular Sequence Data, Myeloid Cell Leukemia Sequence 1 Protein, Peptide Fragments, Peptide Fragments: chemistry, Peptide Fragments: metabolism, Protein Binding, Protein Interaction Mapping, Proto-Oncogene Proteins, Proto-Oncogene Proteins c-bcl-2, Proto-Oncogene Proteins c-bcl-2: chemistry, Proto-Oncogene Proteins c-bcl-2: metabolism, Proto-Oncogene Proteins: chemistry, Proto-Oncogene Proteins: metabolism

Interactions between Bcl-2-like proteins and BH3 domains play a key role in the regulation of apoptosis. Despite the overall structural similarity of their interaction with helical BH3 domains, Bcl-2-like proteins exhibit an intricate spectrum of binding specificities whose underlying basis is not well understood. Here, we characterize these interactions using Rosetta FlexPepBind, a protocol for the prediction of peptide binding specificity that evaluates the binding potential of different peptides based on structural models of the corresponding peptide-receptor complexes. For two prominent players, Bcl-xL and Mcl-1, we obtain good agreement with a large set of experimental SPOT array measurements and recapitulate the binding specificity of peptides derived by yeast display in a previous study. We extend our approach to a third member of this family, Bcl-2: we test our blind prediction of the binding of 180 BIM-derived peptides with a corresponding experimental SPOT array. Both prediction and experiment reveal a Bcl-2 binding specificity pattern that resembles that of Bcl-xL. Finally, we extend this application to accurately predict the specificity pattern of additional human BH3-only derived peptides. This study characterizes the distinct patterns of binding specificity of BH3-only derived peptides for the Bcl-2 like proteins Bcl-xL, Mcl-1, and Bcl-2 and provides insight into the structural basis of determinants of specificity.