Fig. 4: Macrocycle-derived CIDEs bind PSMD2 and BRD4 with high affinity.
From: Targeted degradation via direct 26S proteasome recruitment
a, Schematic of MC1 and four amino acids chosen as conjugation points. AcF, acetyl l-phenylalanine. b, Click-based strategy used to conjugate a BRD4 ligand (BETi) with various linkers to each macrocycle via a propargyl-serine introduced at each of the positions highlighted in a. c,d, PSMD2-based CIDEs (Supplementary Table 3) retain nanomolar binding affinities to purified 26S proteasome (c) and BRD4 (d) in permeabilized cells; P4, PEG4; P6, PEG6; C7P6, -(CH2)6CONH-(C7) + PEG6; P4P6, PEG4 + PEG6. Bars represent the mean ± s.d. of at least three independent experiments. e, CIDEs mediate formation of the PSMD2–BRD4BD1 ternary complex as observed by pulldown assay. Recombinant PSMD2 co-purifies with biotinylated BD1 pulled down with Streptavidin beads in the presence of all 16 CIDE compounds but not in the presence of BETi linker compound without macrocycle or macrocycle alone. Lanes are color coded based on their conjugation point in a; IP, immunoprecipitation. Data were reproduced in two independent experiments.
