At Creative Peptides, we specialize in custom peptide-antibody conjugation (PAC) — an advanced bioconjugation technology that integrates high-specificity antibodies with functional peptides to generate next-generation targeted therapeutics and diagnostics. By combining precise antibody engineering, rational peptide design, and site-selective conjugation strategies, our scientists deliver stable, reproducible, and biologically active peptide–antibody conjugates tailored to your research or clinical development goals.
Functional peptides are site-specifically conjugated to a monoclonal antibody via defined linker chemistries, enabling enhanced targeting, cellular interaction, or conditional biological functionality while preserving antibody structure.While monoclonal antibodies exhibit excellent target specificity, their therapeutic performance can be limited by poor tissue penetration, insufficient intracellular delivery, and lack of multifunctionality.
Peptide-antibody conjugation directly addresses these limitations by:
We provide comprehensive, end-to-end Peptide-Antibody Conjugation (PAC) services designed for biologics discovery, preclinical development, and CMC-ready advancement. Our platform integrates antibody-compatible conjugation chemistry, functional peptide engineering, and rigorous analytical characterization to deliver reproducible peptide–antibody conjugates with controlled conjugation profiles, preserved antigen binding, and development-focused documentation.
Successful PAC development starts with a biologics-centered design strategy. Our scientists collaborate with your discovery and CMC teams to define a conjugation route that preserves antibody developability while achieving the desired biological function.
Deliverables include a technical roadmap, risk assessment (aggregation, potency shift, DAR/PAR control), and an analytical plan aligned with your study stage.
We support PAC projects using research-grade or GMP-grade antibodies and antibody fragments. Our preparation workflow focuses on maintaining structural integrity, minimizing aggregation, and ensuring conjugation readiness.
Our objective is to preserve antigen binding and Fc-related properties while enabling predictable conjugation outcomes.
We design and synthesize peptides specifically optimized for antibody conjugation, balancing functionality with developability (solubility, stability, and conjugation compatibility).
Peptides can be customized for charge, hydrophobicity, and length to reduce aggregation risk and support downstream performance.
Using antibody-compatible, validated chemistries, we perform controlled PAC under optimized conditions to maximize yield while minimizing antibody perturbation and conjugate heterogeneity.
We prioritize reproducibility and preservation of antigen-binding affinity, supporting programs that require robust batch-to-batch consistency.
Each PAC product undergoes purification and characterization designed to meet biologics development expectations, including identity confirmation, conjugation profiling, and stability evaluation.
Where required, we can align analytical deliverables with IND-enabling expectations for comparability and CMC readiness.
Our PAC platform supports scale-up from feasibility and lead optimization to preclinical supply and GMP-ready manufacturing planning, with an emphasis on traceability and regulatory-aligned documentation.
We help teams de-risk development by building reproducibility, comparability, and documentation into the process early.
To complement chemical development, we can support biologics-focused evaluation through qualified partners to help confirm that conjugation improves function without compromising developability.
These options help accelerate go/no-go decisions and strengthen translational readiness of PAC candidates.
Selecting the right peptide is critical for achieving the desired biologic behavior of a Peptide-Antibody Conjugate (PAC), including targeting, tissue penetration, cellular uptake, intracellular trafficking, or conditional activation. Below are commonly used peptide categories and how they are applied in PAC design.
| Peptide Type | Main Function | Typical Examples | Typical Applications | Key Advantages in PAC |
|---|---|---|---|---|
| Targeting Peptides | Increase tissue/receptor selectivity and local exposure | RGD/cRGD, NGR, Angiopep-2, tumor-homing motifs (project-specific) | Oncology targeting, CNS/BBB-relevant programs, tissue-directed delivery | Improves localization and on-target exposure; can reduce off-target burden |
| Cell-Penetrating Peptides (CPPs) | Promote cellular uptake and internalization | TAT, Penetratin, R8/R9, Transportan (select case-dependent) | Intracellular delivery concepts, internalization enhancement studies | Boosts uptake in relevant models; enables exploration of intracellular targets |
| Endosomal Escape Peptides | Facilitate endosomal release to improve cytosolic access | INF7, GALA, HA2-derived motifs, pH-responsive amphipathic peptides | Intracellular trafficking optimization, functional delivery validation | Improves functional delivery where endosomal trapping is limiting |
| Tumor-Penetrating Peptides | Enhance deep tumor penetration and retention | iRGD and related penetration-enhancing motifs (project-dependent) | Solid tumor programs, stromal-rich tumors, perfusion-limited lesions | May improve intratumoral distribution beyond antibody diffusion limits |
| Conditionally Activatable / Responsive Peptides | Enable microenvironment-triggered activation or release | Protease-cleavable linkers (MMP/cathepsin motifs), pH-labile designs | Tumor microenvironment targeting, conditional activation strategies | Improves selectivity by activating function preferentially at disease sites |
| Half-Life Extension / PK-Modulating Peptides | Modulate circulation time and biodistribution (program-specific) | Albumin-binding peptide motifs (selected designs), PEG/spacer-assisted | PK tuning, exposure optimization for biologics candidates | Supports PK optimization when distribution/exposure is a key constraint |
| Solubility / Developability-Optimizing Peptides | Improve solubility and reduce aggregation risk (design-dependent) | Charge-balanced / hydrophilicity-tuned peptide segments | Early feasibility and lead optimization; formulation-friendly PAC | Helps maintain developability while adding functionality |
Antibody format selection impacts conjugation site options, peptide-to-antibody ratio (PAR) control, developability, and downstream manufacturability. We support a range of antibody modalities commonly used in biologics R&D and translational programs.
| Antibody Format | Key Features | Conjugation Considerations | Typical Use Cases | Key Advantages in PAC |
|---|---|---|---|---|
| IgG (Full-Length mAb) | Gold-standard therapeutic scaffold; long half-life; Fc effector options | Site selection on Fc/Fab/hinge; PAR control; aggregation risk management | Therapeutics, imaging, translational studies; ADC-adjacent programs | Strong developability baseline; scalable manufacturing familiarity |
| IgG1 vs IgG4 (Subclass Selection) | IgG1: effector-capable; IgG4: reduced effector function | Choose based on MoA; maintain binding and Fc properties post-conjugation | IgG1 for ADCC/CDC programs; IgG4 for blocking/neutralizing antibodies | Aligns PAC design with mechanism while keeping clinical relevance |
| Fab Fragment | Smaller, Fc-free; often improved tissue penetration | Shorter half-life; fewer conjugation sites; careful stability handling | Diagnostics, imaging, tumor penetration studies | Reduced size can improve distribution; simpler effector profile |
| scFv | Single-chain variable fragment; compact binding module | Format stability varies; conjugation must preserve folding and affinity | Targeting modules, research tools, internalization studies | Enables modular engineering and rapid prototyping in discovery |
| Nanobody (VHH) | Very small; high stability; good tissue penetration | Very short half-life unless engineered; controlled conjugation recommended | Imaging, tissue penetration-limited targets, intracellular exploration | Excellent access to sterically restricted epitopes; strong developability in small format |
| Bispecific Antibody | Dual specificity; enables receptor bridging or immune redirection | Complex structure; higher need for site-selective conjugation and comparability | T-cell engager concepts, dual-pathway blockade, targeted delivery | Peptides can tune localization/internalization without altering binding architecture |
| Fc-Fusion / Antibody-Derived Fusion | Fc-enabled half-life with fused binding/functional domains | Conjugation must avoid interfering with fusion domain activity and Fc behavior | Receptor ligands, cytokine fusions, multifunctional biologics | Combines long half-life with modular peptide enhancements |
Site-Specific Conjugation Control
Antibody-compatible, site-selective strategies help minimize heterogeneity and enable controlled peptide-to-antibody ratio (PAR) for consistent performance across batches.
Biologics-First Developability Focus
Our workflow is designed to preserve antibody binding affinity and structural integrity while proactively managing aggregation risk, stability, and formulation compatibility.
Functional Peptide Engineering
We design peptides for targeting, penetration, endosomal escape, or responsiveness, with tunable charge and hydrophobicity to support antibody conjugation and biological performance.
Predictable Biological Behavior
Linker and spacer optimization enables stable attachment and controlled functionality, supporting reproducible activity profiles and meaningful structure–function interpretation.
Advanced Analytical Characterization
Comprehensive QC includes conjugation profiling and intact mass confirmation (LC-MS), plus purity and stability assessment aligned with biologics development expectations.
Scalable & GMP-Ready Execution
From discovery batches to preclinical supply and GMP planning, we build reproducibility, traceability, and documentation into the process to de-risk development.
Reduced Heterogeneity, Higher Consistency
Tight control of conjugation conditions and site selection supports uniform conjugate populations, helping improve comparability and downstream manufacturability.
Fast Turnaround & Technical Depth
Experienced bioconjugation scientists deliver clear technical communication, rapid feasibility testing, and reliable execution aligned with your program timelines.
One-Stop PAC Development Platform
Integrated peptide engineering, antibody-compatible conjugation, purification, and QC reduce vendor handoffs and streamline your path from concept to development-ready conjugates.
Our PAC workflow is built for biologics programs that demand reproducibility, traceability, and development-ready documentation. From initial feasibility to scalable supply, each step is designed to preserve antibody integrity, control peptide-to-antibody ratio (PAR), and deliver conjugates suitable for discovery, preclinical studies, and CMC planning.
1
Project Consultation & Biologics Design Planning
2
Antibody Preparation & Functional Peptide Engineering
3
Site-Selective Conjugation & Optimization
4
Purification, Characterization & Biologics-Focused QC
5
Scale-Up, Documentation & Delivery
Peptide-Antibody Conjugation (PAC) is a versatile biologics engineering strategy that expands antibody functionality beyond conventional modalities. By integrating functional peptides onto antibodies with controlled conjugation profiles, PAC can enhance targeting precision, cellular access, and conditional activity for a wide range of therapeutic and diagnostic programs.
Looking to enhance antibody functionality, improve targeting precision, or explore next-generation biologic conjugates beyond traditional ADCs? Our Peptide-Antibody Conjugation (PAC) platform is designed to support biologics programs from early feasibility through preclinical development and CMC-ready advancement. Partner with Creative Peptides to access expert-driven peptide engineering, antibody-compatible conjugation strategies, and biologics-focused analytical support. Whether you are evaluating a novel PAC concept, optimizing conjugation sites and linkers, or preparing for IND-enabling studies, our team delivers reproducible, scalable solutions tailored to your therapeutic objectives. Contact us today to discuss your antibody format, peptide strategy, and development goals, or request a confidential technical consultation and customized quotation to accelerate your PAC program.
A linker molecule is used to covalently bond the peptide and the antibody together. This process ensures that the targeting capabilities of the antibody are combined with the biological activities of the peptide.
Peptide-antibody conjugates are often used in scientific research, particularly in fields like immunology, neuroscience, and cancer research. They can be used for detecting and quantifying specific proteins or cells, and therapeutically by delivering peptides to specific cells in the body.
Please provide us with detailed information about your peptide and antibody, including sequences, concentrations, volumes, and desired conjugation ratio. Also, note any specific requirements for your project, be it for immunoassay development, antibody drug conjugate development, or other applications.
The timeframe can vary depending on the complexity of the project. Generally, custom peptide-antibody conjugation service takes about 2-4 weeks from receipt of your peptide and antibody.
We employ stringent quality control measures to ensure the high-quality and efficacy of our products. This includes purity checks, identification, concentration assessments, and functional tests, among others.
Most peptide-antibody conjugates should be stored at -20°C and are stable for at least one year under proper storage conditions. However, the exact conditions may vary depending on the specific conjugate.
