Inhibition of Ras–effector interactions by cyclic peptides

A combinatorial library of 6 × 106 cyclic peptides was synthesized in the one bead-two compound format, with each bead displaying a unique cyclic peptide on its surface and a linear peptide encoding tag in its interior. Screening of the library against K-Ras identified compounds that bound K-Ras with submicromolar affinity and disrupted its interaction with effector proteins.