Enzalutamide

Target: This ligand targets the androgen receptor (AR) ligand-binding domain in biochemical or cellular target-engagement studies.

Mechanism of Action: Used as the target-protein recognition element, this ligand provides the binding interface for the androgen receptor (AR) ligand-binding domain. In PROTAC design, a derivatizable position on the ligand can be connected through an optimized linker to an E3 ligase ligand, such as a CRBN, VHL, or IAP recruiter, while preserving productive target engagement. The resulting bifunctional molecule brings the androgen receptor (AR) ligand-binding domain into proximity with the recruited E3 ligase, enabling ternary-complex formation. If the complex has favorable geometry and residence time, target lysine ubiquitination is promoted, leading to proteasome-dependent degradation in experimental systems.

• Androgen Receptor PROTAC Design: Enzalutamide can be incorporated as an androgen receptor (AR)-binding ligand to build AR-targeting PROTACs. These constructs aim to recruit an E3 ligase to drive AR ubiquitination and degradation, enabling systematic testing of how AR loss alters transcriptional programs, AR co-regulator usage, and downstream signaling under androgen-depleted or resistant conditions.

• PROTAC-Mediated AR Degradation Studies: Use Enzalutamide-based PROTACs to quantify AR degradation kinetics and dose–response relationships across cell models. Researchers can evaluate whether degradation outperforms inhibition alone by measuring AR protein half-life, accumulation of ubiquitinated species, and functional readouts such as PSA and TMPRSS2 expression, supporting mechanistic comparisons between degradation and blockade.

• E3 Ligase Recruitment Optimization: Enzalutamide-derived PROTACs are suitable for screening different E3 ligase recruiters to optimize degradation efficiency and selectivity. By varying linker length, attachment site, and recruiter identity, experiments can map structure–activity relationships and determine how recruitment strength and spatial geometry influence ternary complex formation and productive ubiquitination.

• Resistance Mechanism Exploration: Enzalutamide PROTACs can be used to probe resistance mechanisms that limit conventional AR antagonists. Degradation-focused approaches allow assessment of whether AR degradation persists despite AR mutations, altered co-regulators, or compensatory pathway activation, using proteomics and AR-dependent transcription assays to identify vulnerabilities linked to sustained AR removal.

Enzalutamide is a androgen receptor ligand intended for use as the target-engaging component or reference ligand in PROTAC discovery workflows. Its known small-molecule recognition profile enables rational linker-vector evaluation and comparative degrader design. This molecule is described in detail below.

Structure: The structure of Enzalutamide is characterized by amide/urea/sulfonamide hydrogen-bonding motifs; halogenated aryl/heteroaryl ring system; heteroaromatic protein-recognition scaffold. These features provide defined hydrogen-bonding, hydrophobic, and steric elements that can support affinity retention while enabling analogue-based linker-vector selection.

Reactivity: The sulfur-containing handle can be considered for thioether, disulfide, or maleimide-compatible linker installation if the binding epitope tolerates substitution. For PROTAC construction, the POI ligand can be paired with CRBN ligands such as thalidomide, pomalidomide, or lenalidomide analogues, VHL ligands such as VH032 derivatives, or less common IAP/MDM2/cIAP-recruiting ligands, with alkyl, PEG, piperazine, triazole, or amide linkers screened for ternary-complex formation. In practice, incorporation into PROTACs should begin from derivatives that preserve the reported binding pharmacophore, followed by systematic variation of linker length, polarity, rigidity, and exit-vector geometry to optimize target engagement, E3 recruitment, and cellular degradation readouts.