PROTAC Development for Target Proteins

BOC Sciences provides end-to-end PROTAC development services centered on target proteins, spanning from target protein evaluation and ligand discovery to molecular design, synthesis, degradation validation, and candidate delivery. By integrating chemistry, biology, and computational analysis capabilities, we help clients systematically address target degradability, ligand availability, ternary complex formation, and developability challenges, enabling efficient advancement of protein degrader programs against specific disease-relevant targets.

BOC Sciences' PROTAC Development Services for Target Proteins

Discovery and Design for Target Protein Ligands

We provide systematic ligand discovery and design services for target proteins, including literature mining, structure-based analysis, and hit identification. By evaluating known inhibitors, binders, and tool compounds, we help clients identify suitable warhead candidates with adequate affinity and selectivity for the target protein of interest, establishing a solid foundation for downstream PROTAC assembly.

• Ligand Design for Target Protein
• Structure-based and fragment-based ligand evaluation
• Warhead screening against target protein binding pockets
• Affinity and selectivity profiling of candidate ligands

E3 Ligase Selection and Matching for Target Degradation

Selecting the appropriate E3 ubiquitin ligase is critical for achieving efficient target protein degradation. We evaluate target protein expression patterns, subcellular localization, and tissue distribution to recommend optimal E3 ligase candidates. Our team supports systematic matching strategies using VHL, CRBN, IAP, MDM2, and other ligase systems to maximize ternary complex formation and degradation potency.

• E3 ligase ligand design and optimization
• VHL- and CRBN-based degradation strategies
• IAP and MDM2 ligase system evaluation
• Tissue- and cell-type-specific ligase selection guidance

Linker Design and PROTAC Library Construction

We design and optimize linkers that connect target protein warheads to E3 ligase ligands, balancing length, flexibility, and physicochemical properties to promote productive ternary complex formation. Through iterative design and library construction, we help clients explore diverse PROTAC architectures and identify lead candidates with optimal degradation profiles.

• PEG-, alkyl-, and cleavable linker design options
• Linker length and flexibility optimization
• PROTAC library and warhead library construction
• Structure-activity relationship exploration

PROTAC Synthesis and Chemical Optimization

Our chemistry team delivers high-quality PROTAC synthesis services ranging from milligram-scale preparation of initial candidates to gram-scale production of optimized leads. We support focused analog series synthesis, route development, and chemical optimization to address solubility, stability, and permeability while maintaining degradation activity against the target protein.

• Custom PROTAC synthesis and route scouting
• PROTAC manufacturing services
• Focused analog library preparation
• Solubility, stability, and permeability optimization

In Vitro Degradation Validation for Target Proteins

We provide comprehensive in vitro evaluation services to assess target protein degradation, including biochemical binding assays, cell-based degradation screening, and mechanistic confirmation. Our platform enables quantitative measurement of degradation efficiency, DC₅₀ determination, and selectivity profiling against closely related protein family members.

• Degradation efficiency assessment and DC₅₀ determination
• Binding affinity measurement
• PROTAC activity assay and dose-response analysis
• Selectivity evaluation across protein family members

In Vivo Degradation Validation for Target Proteins

To support target protein degradation in physiologically relevant contexts, we provide in vivo evaluation services encompassing pharmacokinetic assessment, tissue distribution analysis, and target engagement confirmation. These studies help bridge the gap between cellular degradation data and biological outcomes in living systems.

• Pharmacokinetic profiling and exposure assessment
• Tissue distribution and target engagement analysis
• Target protein degradation confirmation in vivo
• Pharmacodynamic evaluation

Target Protein Categories Addressed by Our PROTAC Services

PROTACs Targeting Kinases

Protein kinases represent one of the most extensively validated target classes for PROTAC development. We support degradation programs against a broad spectrum of kinase targets, including CDK family proteins, BTK, EGFR, JAK, ALK, FAK, and RTK family members. Our kinase-directed PROTAC services leverage established inhibitor scaffolds as warheads and apply structure-guided design to achieve selective degradation of oncogenic and drug-resistant kinase variants.

• CDK, BTK, EGFR, JAK, ALK, FAK, and RTK target coverage
• Kinase inhibitor-to-warhead conversion strategies
• Selectivity profiling against kinase family members
• Resistance mutant-targeted degradation design

PROTACs Targeting Epigenetic Regulators

Epigenetic regulatory proteins such as BET family proteins (BRD2, BRD4, BRD3) and histone deacetylases control gene expression programs implicated in cancer and inflammatory diseases. We design PROTACs that selectively remove these epigenetic readers and modifiers, enabling functional studies and therapeutic exploration beyond the limitations of conventional inhibitors.

• BET protein (BRD2, BRD3, BRD4) degradation programs
• Histone deacetylase-targeted PROTAC design
• Epigenetic target validation support
• Gene expression and chromatin modulation studies

PROTACs Targeting Transcription Factors

Transcription factors have historically been considered challenging drug targets due to the absence of well-defined binding pockets. PROTAC technology offers a promising approach to address this target class by leveraging transcription factor-associated protein-protein interactions or DNA binding domains for ligand engagement. We support exploratory programs targeting transcription factors such as c-Myc and KDM5B, applying innovative ligand discovery strategies.

• c-Myc and KDM5B degradation program support
• Protein-protein interaction interface targeting
• Exploratory ligand discovery for transcription factors
• Functional consequence assessment of transcription factor removal

PROTACs Targeting Nuclear Receptors

Nuclear receptors play central roles in hormone signaling and represent important targets for oncology and endocrine disorders. We develop PROTACs against key nuclear receptors including androgen receptor (AR) and estrogen receptor (ER), leveraging well-characterized antagonist ligands to achieve receptor degradation. This approach addresses resistance mechanisms associated with traditional receptor inhibitors.

• AR and ER targeted degradation development
• Antagonist-to-warhead optimization
• Hormone receptor resistance mechanism addressing
• Nuclear receptor selectivity profiling

PROTACs Targeting Anti-Apoptotic Proteins

Anti-apoptotic proteins such as BCL-xL and BCL-2 enable cancer cell survival and are associated with therapeutic resistance. We support PROTAC programs designed to selectively degrade anti-apoptotic proteins, restoring apoptosis pathways and sensitizing cancer cells to treatment. Our approach combines warhead optimization with appropriate E3 ligase selection to achieve efficient degradation in tumor-relevant cellular contexts.

• BCL-xL and BCL-2 degradation program support
• Apoptosis pathway restoration studies
• Tumor cell sensitization evaluation
• Selective degradation in cancer vs. normal cells

PROTACs Targeting Scaffold Proteins

Scaffold proteins perform critical regulatory functions through protein-protein interactions independent of enzymatic activity, making them largely intractable with traditional small-molecule inhibitors. PROTAC-mediated degradation removes the entire scaffold protein, abolishing both catalytic and structural functions. We support exploratory and targeted programs against scaffold proteins that drive disease-relevant signaling complexes.

• Scaffold protein degradability assessment
• Protein-protein interaction-based ligand discovery
• Functional consequence evaluation of scaffold removal
• Signaling pathway modulation studies

PROTACs Targeting Phosphatases

Protein phosphatases regulate signaling networks through dephosphorylation and represent an emerging target class for degradation. We support phosphatase-directed PROTAC development using catalytic site inhibitors and allosteric modulators as warheads, combined with optimized linkers and E3 ligase ligands to achieve selective phosphatase degradation and functional validation.

• Phosphatase catalytic and allosteric ligand evaluation
• Phosphatase-selective PROTAC design
• Phosphorylation network modulation assessment
• Signaling pathway impact analysis

PROTACs Targeting Emerging Protein Classes

Beyond established target categories, we support PROTAC development against emerging and challenging protein classes, including RAS family proteins (KRAS), PI3K, ERK5, and other difficult-to-drug targets. Our flexible development platform accommodates novel target biology and innovative ligand discovery approaches.

• KRAS, PI3K, ERK5 degradation support
• Novel target class feasibility evaluation
• Innovative ligand discovery strategy development
• Exploratory degradation program design

Our Solutions for Target Protein PROTAC Development Challenges

Targeted protein degradation presents distinct challenges at each stage of development. We provide integrated solutions that help clients navigate target uncertainty, ligand identification, degradation optimization, and developability improvement.

Solution for Target Selection and Degradability Uncertainty

Selecting the right target protein for PROTAC development requires systematic evaluation of expression levels, ligand availability, E3 ligase proximity, and biological relevance. We conduct comprehensive target assessments combining bioinformatics analysis, literature mining, and protein structure modeling to determine degradability potential. This approach helps clients prioritize targets with higher development feasibility and reduce investment risk in early-stage programs.

Solution for Ligand Identification and Affinity Optimization

Identifying suitable ligands for the target protein is a critical bottleneck. We apply multiple ligand discovery strategies including virtual screening, molecular docking, fragment-based approaches, and known inhibitor repurposing to identify warhead candidates. Through iterative affinity optimization and selectivity profiling, we help clients secure ligands with sufficient binding strength and target specificity for effective PROTAC assembly.

Solution for Degradation Efficiency and Selectivity Optimization

Achieving robust target protein degradation while maintaining selectivity against closely related family members requires careful optimization of the ternary complex. We systematically vary linker length, flexibility, and architecture while evaluating different E3 ligase systems to identify combinations that maximize degradation potency. Our ternary complex formation assays and high-throughput screening capabilities enable rapid iteration and candidate identification.

Solution for Developability and Drug-Like Property Improvement

PROTAC molecules often face challenges related to molecular weight, permeability, and solubility due to their bifunctional architecture. We address these developability concerns through focused chemical optimization, linker modification, and strategic selection of warhead and ligand components. By monitoring solubility, stability, and permeability parameters in parallel with degradation activity, we help clients identify candidates that balance biological efficacy with acceptable physicochemical properties.

End-to-End PROTAC Development Workflow for Target Proteins

Advantages of PROTAC Development for Target Proteins

Enables Direct Functional Removal of Disease-Relevant Target Proteins

Unlike traditional inhibitors that merely block enzymatic activity, PROTACs eliminate the target protein entirely, removing both catalytic and scaffolding functions. This complete functional knockdown enables more definitive target validation and can reveal biological effects that occupancy-based approaches cannot achieve.

Supports Target Validation Beyond Occupancy-Based Inhibition

PROTAC technology allows researchers to assess the phenotypic consequences of removing a target protein rather than just inhibiting its activity. This is particularly valuable for validating proteins with both catalytic and non-catalytic functions, as degradation abolishes all protein-associated activities.

Reveals Protein Function Through Degradation-Driven Phenotypic Readouts

Targeted degradation provides a powerful tool for functional genomics and target discovery. By selectively removing individual proteins and observing resulting phenotypic changes, researchers can build detailed functional maps of protein-driven pathways and identify new therapeutic opportunities.

Allows Target-Specific Optimization Based on Degradation Profiles

Each target protein presents unique challenges in terms of ligand availability, E3 ligase pairing, and ternary complex geometry. PROTAC development enables customized molecular optimization tailored to the specific degradation profile of each target, rather than relying on generic inhibitor frameworks.

Applications of Target Protein PROTAC Development

Client Success Stories: Target Protein PROTAC Development

Why Choose BOC Sciences for Target Protein PROTAC Development?

Broad Target Coverage Across Major Protein Classes

We support PROTAC development against kinases, nuclear receptors, epigenetic regulators, transcription factors, anti-apoptotic proteins, scaffold proteins, phosphatases, and emerging target categories, providing comprehensive coverage across the major target protein classes relevant to drug discovery.

Integrated Target-to-Candidate Development Capability

Our end-to-end service platform seamlessly connects target assessment, ligand discovery, molecular design, synthesis, and degradation validation, eliminating the inefficiencies of coordinating multiple vendors and ensuring scientific continuity throughout the project.

Structure-Based Design and Advanced Computational Analysis

We leverage molecular docking, molecular dynamics simulations, and protein structure modeling to guide rational PROTAC design, predict ternary complex formation, and optimize linker architecture before committing to synthesis resources.

Flexible Service Models for Diverse Project Needs

Whether clients require full program management from target evaluation to candidate delivery or targeted support for specific phases such as ligand optimization or degradation validation, we tailor engagement models to match project scope, timeline, and budget.

Experienced Team with Deep Target Biology Knowledge

Our multidisciplinary team combines expertise in medicinal chemistry, structural biology, computational modeling, and cell-based assay development, enabling informed decision-making at every stage of target protein PROTAC development.

High-Quality Data and Clear Decision Support

We deliver robust, reproducible experimental data with comprehensive analysis and clear interpretation, enabling clients to make informed decisions about target prioritization, candidate selection, and program advancement strategies.