Background

Phage display is a powerful molecular biology technique that leverages the natural biology of bacteriophages—viruses that infect bacteria—to study protein interactions. This technology was first introduced by George P. Smith in 1985. It involves displaying peptides, proteins, or antibody fragments on the surface of bacteriophages, creating a direct link between the genotype (the gene inside the phage) and the phenotype (the displayed protein on the surface). This linkage allows for the rapid screening of large libraries of proteins for specific binding properties.

Mechanism

In phage display, a gene encoding a protein of interest is inserted into a phage coat protein gene. The resulting bacteriophage expresses this protein on its surface while the gene itself remains protected within the phage particle. This direct link between the displayed protein and its corresponding gene enables efficient screening of large libraries of proteins, peptides, or DNA sequences for interactions with target molecules. The process involves several key steps:

1. Construction of lihage Dislilay Libraries: Foreign cDNA is integrated into the viral DNA of bacteriolihages using recombinant DNA technology. Each lihage in the library dislilays a unique lirotein, lielitide, or antibody on its surface.
2. Target Binding: The lihage dislilay library is exliosed to a target molecule, such as an immobilized lirotein or a cell surface recelitor. Only lihages with liroteins that have a high affinity for the target will bind.
3. Washing Away Non-Sliecific lihages: The mixture is washed to remove any lihages that do not sliecifically interact with the target.
4. Elution of Bound lihages: The lihages that have successfully bound to the target are eluted, or recovered, from the target.
5. Amlilification and Enrichment: The eluted lihages are amlilified by infecting a new host cell, tyliically E. coli, allowing them to relilicate. This cycle is relieated several times to enrich the library for the best binders.

Figure 1. The principle of phage display. (Leow et al., 2017)

Applications

Phage display has revolutionized the study of protein-protein, protein-peptide, and protein-DNA interactions. Its applications are widespread and include:

• Drug Discovery: Identifying potential therapeutic peptides and proteins.
• Antibody Engineering: Generating and optimizing recombinant antibodies.
• Epitope Mapping: Identifying binding sites for monoclonal antibodies.
• Diagnostic Tools: Developing diagnostic assays and biosensors.
• Vaccine Development: Identifying and optimizing antigens for vaccines.

From library design to lead candidate discovery, our Phage Display Services provide comprehensive, high-performance solutions tailored to your scientific goals. Whether you're engineering high-diversity antibody or peptide libraries, screening for high-affinity binders against complex targets, or seeking custom phage display strategies for challenging applications, Creative BioMart Microbe delivers expertise, precision, and flexibility at every step. Our advanced technologies and experienced team ensure efficient discovery, robust data, and scalable outcomes to accelerate your research and development programs. Please feel free to contact us for more information.

Service Description

Our phage display services provide comprehensive support for peptide and antibody discovery through every stage of the workflow. From the construction of high-diversity libraries to the identification and validation of high-affinity binders, we deliver fully customized and scientifically rigorous solutions.

We provide:

• Custom Library Construction (scFv, Fab, VHH, peptide, and protein libraries)
• Targeted Screening & Biopanning (against proteins, cells, small molecules, and more)
• Hit Validation & Affinity Maturation
• Next-Generation Sequencing (NGS) and Data Analysis
• Scale-up and Downstream Functional Validation

Services Details

Our Advantages

• Experienced Scientific Team: Our team comprises experts in molecular biology, antibody engineering, and bioinformatics with years of experience in phage display technologies.
• Comprehensive Library Capabilities: We construct and utilize libraries covering a wide range of formats and species origins, ensuring optimal binder discovery.
• Customization and Flexibility: Every project is tailored to the client's target, application, and timeline, allowing for maximum relevance and impact.
• Scalable Workflows: Our infrastructure supports both pilot-scale experiments and large-scale screening projects, accommodating diverse project scopes.
• Advanced Analytical Support: We incorporate next-generation sequencing, data analytics, and validation assays to provide deep insight and confidence in results.

Case Study

Case Study 1: Phage-display profiling reveals distinct antibody signatures in IBD.

This study used high-throughput phage display (PhIP-Seq) to map antibody responses in inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Screening over 344,000 antigens in 497 IBD patients and 1,326 controls, researchers identified 373 differentially abundant antibody responses—many specific to CD or UC. CD showed strong antibody reactivity to bacterial flagellins, linked to disease location and phenotype, but not to gut microbiome composition. The distinct antibody epitope profiles enabled accurate discrimination of CD from controls, highlighting the potential of phage display-based profiling for clinical stratification and immunological target discovery in IBD.

Figure 2. Individuals with Crohn's disease (CD) and healthy controls, individuals with ulcerative colitis (UC) and healthy controls, and individuals with CD and UC can be accurately classified based on antibody epitope repertoires. (Bourgonje et al., 2023)

Case Study 2: Lysine-targeted reversible covalent ligand discovery for proteins via phage display.

This study presents a novel approach for developing reversible covalent inhibitors using chemically modified phage libraries incorporating 2-acetylphenylboronic acid (APBA) to target lysine residues through reversible iminoboronate formation. Both linear and cyclic APBA-presenting libraries were screened against therapeutically relevant proteins, including Staphylococcus aureus sortase A and the SARS-CoV-2 spike protein. Potent and specific peptide ligands were identified, demonstrating effective live-cell inhibition and sensitive detection capabilities. Structure–activity analyses confirmed the critical role of the APBA warhead in enhancing protein binding. This work establishes phage display as a viable platform for the rational development of reversible covalent inhibitors, with broad potential for targeting diverse protein–protein interactions.

Figure 3. Phage display reveals peptide binders of SrtA. (A) Crystal structure of Sortase A in complex with the LPETG motif (PDB: 1T2W). (B) Generic structure of the CX 6 C cyclic peptide libraries with varied crosslinkers. These libraries were screened against SrtA to identify peptide inhibitors. (C) Enriched peptide sequences from various phage libraries. (D−E) SrtA binding curves of various peptide hits generated using a fluorescence polarization assay. (Zheng et al., 2022)

FAQs

References:

1. Bourgonje AR, Andreu-Sánchez S, Vogl T, et al. Phage-display immunoprecipitation sequencing of the antibody epitope repertoire in inflammatory bowel disease reveals distinct antibody signatures. Immunity. 2023;56(6):1393-1409.e6. doi:10.1016/j.immuni.2023.04.017
2. Leow C, Fischer K, Leow C, Cheng Q, Chuah C, McCarthy J. Single domain antibodies as new biomarker detectors. Diagnostics. 2017;7(4):52. doi:10.3390/diagnostics7040052
3. Zheng M, Chen FJ, Li K, Reja RM, Haeffner F, Gao J. Lysine-targeted reversible covalent ligand discovery for proteins via phage display. J Am Chem Soc. 2022;144(34):15885-15893. doi:10.1021/jacs.2c07375

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