A Synthetic Library of Cell-Permeable Molecules

Abstract

Small molecules that induce or stabilize the association of macromolecules have proven to be useful effectors of a wide variety of biological processes. To date, all examples of such chemical inducers of dimerization have involved known ligands to well-characterized proteins. The generality of this approach could be broadened by enabling the discovery of heterodimerizers that target known macromolecules having no established ligand, or heterodimerizers that produce a novel biologic response in screens having no predetermined macromolecular target. Toward this end, we report the construction of a diversified library of synthetic heterodimerizers consisting of an invariant ligand that targets the FK506-binding protein (AP1867) attached to 320 substituted tetrahydrooxazepines (THOXs). The THOX components were generated by a combination of liquid- and solid-phase procedures employing sequential Mitsonobu displacements to join two structurally diversified olefin-containing monomers, followed by ruthenium-mediated olefin metathesis to effect closure of the seven-membered ring. The 320 resin-bound THOX ligands were coupled in parallel to AP1867, and the products were released from the resin to yield candidate heterodimerizers in sufficient yield and purity to be used directly in biologic testing. A representative panel of 25 candidate heterodimerizers were tested for their ability to pass through the membrane of human fibrosarcoma cells, and all were found to possess activity in this tissue culture system. These studies pave the way for further studies aimed at using small-molecule inducers of heterodimerization to effect novel biological responses in intact cells.

Solution‐Phase Combinatorial Libraries: Modulating Cellular Signaling by Targeting Protein–Protein or Protein–DNA Interactions

“…[191] These chemical inducers of protein dimerization (CIDs) pioneered by Schreiber and Crabtree et al have been used to modulate cell membrane receptor signaling, [192] to control gene expression, [192c, 193] to selectively antagonize cellular processes, [194] to identify protein-ligand partners, [195] and even to target protein heterodimers with no established ligand. [196] Cell growth, differentiation, migration, and apoptosis are regulated in part by growth factors or cytokines. These factors are unable to penetrate the cell membrane and exert their effects by binding to cell surface receptors.…”

CC Bond‐Forming Reactions

“…A 320-member library of cell-permeable molecules, with a tetrahydrooxazepine (THOX) core has been synthesized on a trityl resin by using RCM as the cyclative step [224]. These compounds have been tested in the search of candidate heterodimerizers.…”

Prolegomena zum experimentellen Engineering des genetischen Codes durch Erweiterung seines Aminosäurerepertoires

“…Aus diesem Grund ist die systematische Herstellung von Bibliotheken zellpermeabler Aminosäuren ein wichtiges Forschungsfeld. [199] Extrachromosomale heterologe Expressionssysteme in Mikroorganismen sind besonders gut geeignet für die Erweiterung des Aminosäurerepertoires, da sie sich schnell vermehren und leicht zu handhaben sind. Diese Systeme können sowohl für den positionsspezifischen als auch für den multiplen Einbau nichtkanonischer Aminosäuren programmiert werden, indem man sie mit zusätzlichen Translationskomponenten ausstattet.…”