Identification of a Peptoid Inhibitor of the Proteasome 19S Regulatory Particle

Division of Translational Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9185, USA.
Journal of the American Chemical Society (Impact Factor: 12.11). 07/2007; 129(25):7750-1. DOI: 10.1021/ja072027p
Source: PubMed


The first chemical inhibitor of the 19S regulatory particle (RP) of the proteasome is described. The molecule was identified by screening a library of nucleoside-capped peptoids for binding to the yeast 26S proteasome in a crude extract. The hit was resynthesized and shown to block 19S RP-mediated protein unfolding in vitro and proteasome-mediated turnover of p27 in HeLa cells.

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    • "In order to substantially increase the number of compounds that could be used in such a screen, we first developed a protocol that allowed one-bead, one-compound (OBOC) libraries synthesized on hydrophilic TentaGel beads to be used directly in the screening step. Libraries of hundreds of thousands, or even millions, of peptoids are easily prepared in this format by splitand-pool solid-phase synthesis (Alluri et al., 2003; Figliozzi et al., 1996; Lam et al., 1991), and these libraries can be used productively in screening experiments using recombinant proteins (Lim et al., 2007; Xiao et al., 2007) or cells (Lau et al., 2002; Mikawa et al., 2004; Udugamasooriya et al., 2008) as targets. The strategy that we envisioned is shown in Figure 1A. "
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    Chemistry & biology 03/2013; 20(3):351-9. DOI:10.1016/j.chembiol.2012.12.009 · 6.65 Impact Factor
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    • "Because hundreds of suitable primary amines are available commercially or synthesized readily, large one-bead one-compound (OBOC) libraries of peptoids can be made easily using the split and pool strategy (Lam et al., 1991). These libraries can be screened on bead against labeled, soluble proteins (Alluri et al., 2003; Lim et al., 2007; Wrenn et al., 2007; Xiao et al., 2007) or against cells (Aina et al., 2005; Lee et al., 2010a; Udugamasooriya et al., 2008) to identify novel protein ligands. However, these ''hits'' do not generally display high affinity, with rare exceptions (Zuckermann et al., 1994). "
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    • "On-bead screening is a miniaturized high-throughput screening method for identifying bioactive ligands from one-bead one-compound combinatorial libraries [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]. In a typical on-bead screening assay, one-bead one-compound combinatorial libraries are incubated with tagged target protein and the binding of the target protein to bead-immobilized compounds on the surface of individual beads is used to select hit beads for further analysis [14] [15]. "
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