Helix-stabilized cyclic peptides as selective inhibitors of steroid receptor-coactivator interactions.

ABSTRACT: The interaction between nuclear receptors and coactivators provides an arena for testing whether protein-protein interactions may be inhibited by small molecule drug candidates. We provide evidence that a short cyclic peptide, containing a copy of the LXXLL nuclear receptor box pentapeptide, binds tightly and selectively to estrogen receptor alpha. Furthermore, as shown by x-ray analysis, the disulfide-bridged nonapeptide, nonhelical in aqueous solutions, is able to adopt a quasihelical conformer while binding to the groove created by ligand attachment to estrogen receptor alpha. An i, i+3 linked analog, H-Lys-cyclo(d-Cys-Ile-Leu-Cys)-Arg-Leu-Leu-Gln-NH2 (peptidomimetic estrogen receptor modulator 1), binds with a Ki of 25 nM, significantly better than an i, i+4 bridged cyclic amide, as pr

SUBMITTER: Leduc AM 

PROVIDER: S-EPMC208747 | biostudies-literature | 2003 Sep

REPOSITORIES: biostudies-literature