Structure-Based Design of High-Affinity Macrocyclic FKBP51 Inhibitors

J Med Chem. 2021 Mar 25;64(6):3320-3349. doi: 10.1021/acs.jmedchem.0c02195. Epub 2021 Mar 5.

Abstract

The FK506-binding protein 51 (FKBP51) emerged as a key player in several diseases like stress-related disorders, chronic pain, and obesity. Linear analogues of FK506 called SAFit were shown to be highly selective for FKBP51 over its closest homologue FKBP52, allowing the proof-of-concept studies in animal models. Here, we designed and synthesized the first macrocyclic FKBP51-selective ligands to stabilize the active conformation. All macrocycles retained full FKBP51 affinity and selectivity over FKBP52 and the incorporation of polar functionalities further enhanced affinity. Six high-resolution crystal structures of macrocyclic inhibitors in complex with FKBP51 confirmed the desired selectivity-enabling binding mode. Our results show that macrocyclization is a viable strategy to target the shallow FKBP51 binding site selectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Crystallography, X-Ray
  • Drug Design
  • Humans
  • Macrocyclic Compounds / chemistry*
  • Macrocyclic Compounds / pharmacology*
  • Models, Molecular
  • Protein Conformation / drug effects
  • Protein Domains / drug effects
  • Tacrolimus Binding Proteins / antagonists & inhibitors*
  • Tacrolimus Binding Proteins / chemistry
  • Tacrolimus Binding Proteins / metabolism

Substances

  • Macrocyclic Compounds
  • Tacrolimus Binding Proteins
  • tacrolimus binding protein 5