(S,R,S)-AHPC-C5-COOH (VH032-C5-COOH) is a synthesized E3 ligase ligand-linker conjugate, contains the VH032 VHL-based ligand and a linker to form PROTACs. VH-032 is a selective and potent inhibitor of VHL/HIF-1α interaction with a Kd of 185 nM, has the potential for the study of anemia and ischemic diseases[1].

PROTACs contain two different ligands connected by a linker; one is a ligand for an E3 ubiquitin ligase and the other is for the target protein.
PROTACs exploit the intracellular ubiquitin-proteasome system to selectively degrade target proteins.The von Hippel-Lindau tumor suppressor protein is the substrate-binding subunit of the VHL E3 ubiquitin ligase, it targets hydroxylated α subunit of HIFs for ubiquitination and subsequent proteasomal degradation.

[1]. Soares P, et al. Group-Based Optimization of Potent and Cell-Active Inhibitors of the von Hippel-Lindau (VHL) E3 Ubiquitin Ligase: Structure-Activity Relationships Leading to the Chemical Probe (2S,4R)-1-((S)-2-(1-Cyanocyclopropanecarboxamido)-3,3-dimethylbutanoyl)-4-hydroxy-N-(4-(4-methylthiazol-5-yl)benzyl)pyrrolidine-2-carboxamide (VH298).J Med Chem. 2018 Jan 25;61(2):599-618.