RMC-4550

Target: This ligand targets SHP2 protein tyrosine phosphatase PTPN11 in biochemical or cellular target-engagement studies.

Mechanism of Action: Used as the target-protein recognition element, this ligand provides the binding interface for SHP2 protein tyrosine phosphatase PTPN11. 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 SHP2 protein tyrosine phosphatase PTPN11 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.

• PROTAC-Mediated Target Degradation: RMC-4550 can be used as a ligand component in PROTAC constructs to drive ubiquitin-dependent degradation of a chosen target protein. By enabling productive ternary complex formation with an E3 ligase, this ligand supports systematic evaluation of degradation potency, selectivity, and dose–response relationships in cellular proteomics assays.

• Ternary Complex Optimization Studies: Incorporate RMC-4550 into linker and conjugation design to optimize ternary complex stability between the target protein and the recruited E3 ligase. Researchers can compare variants to determine how binding geometry and linker length influence ubiquitination efficiency, target engagement duration, and the extent of protein loss measured by immunoblotting or mass spectrometry.

• Structure–Activity Relationship Mapping: Use RMC-4550 in a PROTAC SAR workflow to correlate ligand properties with degradation outcomes. Systematic modifications can identify features that improve target binding while preserving E3 recruitment, enabling identification of degradation “hot spots” and refinement of physicochemical parameters that affect cell permeability and intracellular residence time.

• Pathway and Mechanism Profiling: Deploy RMC-4550-based PROTACs to interrogate degradation mechanisms and downstream pathway effects. Time-course experiments, proteasome dependency tests, and rescue studies with pathway inhibitors can distinguish degradation-driven phenotypes from occupancy-only effects, supporting mechanistic validation and biomarker discovery for target-dependent cellular responses.

RMC-4550 is a SHP2 phosphatase 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 RMC-4550 is characterized by primary or secondary amine/basic nitrogen centers; phenol or alcohol functionality; halogenated aryl/heteroaryl ring system. These features provide defined hydrogen-bonding, hydrophobic, and steric elements that can support affinity retention while enabling analogue-based linker-vector selection.

Reactivity: The amine/basic nitrogen-containing motif can be evaluated for acylation, sulfonylation, alkylation, or carbamate/urea linker installation when that vector is solvent exposed. 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.