ABSTRACT
An efficient and rapid on-bead screening method was established to identify non-natural peptides that target the Androgen Receptor-cofactor interaction. Binding of the Androgen Receptor ligand binding domain to peptide sequences displayed on beads in a One-Bead-One-Compound format could be screened using fluorescence microscopy. The method was applied to generate and screen both a focussed and a random peptide library. Resynthesis of the peptide hits allowed for the verification of the affinity of the selected peptides for the Androgen Receptor in a competitive fluorescence polarization assay. For both libraries strong Androgen Receptor binding peptides were found, both with non-natural and natural amino acids. The peptides identified with natural amino acids showed great similarity in terms of preferred amino acid sequence with peptides previously isolated from biological screens, thus validating the screening approach. The non-natural peptides featured important novel chemical transformations on the relevant hydrophobic amino acid positions interacting with the Androgen Receptor. This screening approach expands the molecular diversity of peptide inhibitors for nuclear receptors.
Subject(s)
Peptides/chemistry , Receptors, Androgen/chemistry , Amino Acid Sequence , Fluorescence Polarization , Microscopy, Fluorescence , Molecular Sequence DataABSTRACT
Miniprotein phage display screening yields structured peptides with high affinity for the Estrogen Receptor (ER). Hits from apamin phage libraries feature a LXXLL motif specifically placed on the predefined miniprotein helical segment. The apamin scaffold also allows optimization of flanking amino acids to ensure an optimal ER binding affinity.
Subject(s)
Peptides/chemistry , Receptors, Estrogen/chemistry , Amino Acid Motifs , Amino Acid Sequence , Disulfides/chemistry , Molecular Sequence Data , Peptide Library , Protein Binding , Protein Structure, Tertiary , Receptors, Estrogen/metabolismABSTRACT
[structure: see text] An enantioselective total synthesis of cis-solamin has been accomplished using a highly diastereoselective ruthenium tetroxide catalyzed oxidative cyclization as a crucial transformation. Further key steps involved an enzymatic desymmetrization, a TPAP-catalyzed oxidative termini differentiation, and a ruthenium-catalyzed Alder-ene reaction. Thus, the total synthesis of cis-solamin was achieved in 11 steps with an overall yield of 7.5%.
