ABSTRACT
Aberrant apoptosis can lead to acute or chronic degenerative diseases. Mitochondrial outer membrane permeabilization (MOMP) triggered by the oligomerization of the Bcl-2 family proteins Bax/Bak is an irreversible step leading to execution of apoptosis. Here, we describe the discovery of small-molecule inhibitors of Bax/Bak oligomerization that prevent MOMP. We demonstrate that these molecules disrupt multiple, but not all, interactions between Bax dimer interfaces thereby interfering with the formation of higher-order oligomers in the MOM, but not recruitment of Bax to the MOM. Small-molecule inhibition of Bax/Bak oligomerization allowed cells to evade apoptotic stimuli and rescued neurons from death after excitotoxicity, demonstrating that oligomerization of Bax is essential for MOMP. Our discovery of small-molecule Bax/Bak inhibitors provides novel tools for the investigation of the mechanisms leading to MOMP and will ultimately facilitate development of compounds inhibiting Bax/Bak in acute and chronic degenerative diseases.
Subject(s)
Apoptosis/drug effects , Mitochondrial Membranes/drug effects , Neuroprotective Agents/pharmacology , Small Molecule Libraries/pharmacology , bcl-2 Homologous Antagonist-Killer Protein/metabolism , bcl-2-Associated X Protein/metabolism , Animals , Binding Sites , Cells, Cultured , Female , Glutamic Acid/toxicity , HCT116 Cells , Humans , Liposomes/metabolism , Male , Mice , Mitochondrial Membranes/metabolism , Neurons/cytology , Neurons/drug effects , Neurons/metabolism , Neuroprotective Agents/chemistry , Permeability/drug effects , Protein Multimerization/drug effects , Protein Structure, Tertiary , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/isolation & purification , Small Molecule Libraries/chemical synthesis , Small Molecule Libraries/chemistry , Structure-Activity Relationship , bcl-2 Homologous Antagonist-Killer Protein/antagonists & inhibitors , bcl-2 Homologous Antagonist-Killer Protein/genetics , bcl-2-Associated X Protein/antagonists & inhibitors , bcl-2-Associated X Protein/geneticsABSTRACT
Macrocyclic Organo-Peptide Hybrids (MOrPHs) can be prepared from genetically encoded polypeptides via a chemoselective and catalyst-free reaction between a trifunctional oxyamino/amino-thiol synthetic precursor and an intein-fusion protein incorporating a bioorthogonal keto group.
