Peptide Screening Kit Products

KMD Bioscience is committed to providing high-quality phage display libraries and construction kits for subsequent high-throughput library screening. Phage display technology utilizes a phage-based display library to discover candidate binding molecules for targets of interest and has become one of the most potent and widely used laboratory technologies. 

The phage display platform provided by KMD Bioscience is an ultra-high-throughput ligand screening method. Through this technology platform, up to 10¹³/ml peptide or antibody clones that have been displayed by phage can be constructed, and the average number of independent clones can be achieved to 10⁹-10¹⁰/ml. After multiple rounds of panning, up to 10⁵ effective peptide or antibody sequences can be found, which can provide a solid research foundation for the subsequent search for enzyme substrates, protein ligands and highly specific antibodies research. At the same time, with the affinity screening platform of KMD Bioscience, the affinity ranking of different peptides or antibodies and target proteins can be obtained in a short cycle of time (2-3 days), and even the determination of precise affinity can be completed (affinity determination service).

At present, based on the phage display platform, KMD Bioscience can offer a random 7 peptide library, 12 peptide library and C7C library for customers to screen binding molecules, and two kinds of phage library construction kits are available (M13 and T7 phage) for customers to generate customized library for subsequent screening.

Phage Display Systems：

Fig.1 Classification of phage display systems

M13 Phage Display System:

M13 phage mainly uses the pIII and pVIII coat proteins to construct its display system. The pIII is distributed at one end of the phage particle, which can insert exogenous peptide/protein with larger molecular weight into the flexible linkage region at the N-terminal. Thus it can be used to display larger molecular weight proteins. The pVIII is mainly distributed at both sides of phage particles, with higher copy number, and is generally used to screen low-affinity ligand. The pVIII is only suitable for displaying exogenous short peptides due to the small fraction.

T4 Phage Display System:

The viral particles of T4 phage are assembled inside the host cell without goning through the secretory pathway, so it is possible to display a wide range of peptides/proteins which is especially suitable for studying complex proteins that cannot be secreted by E. coli. In addition, there are two binding sites on the coat protein of T4 phage, which are SOC site and HOC site, respectively, so this phage has the ability to fuse two exogenous peptides/proteins with completely different properties and display them on the surface of T4 phage at the same time. Furthermore, the number of displayed copies on the T4 phage is also high.

T7 Phage Display System:

The coat protein of T7 phage commonly used to construct phage display systems is 10B, which can directly lyse the host bacterium without the need to undergo secretion compared to M13. Therefore, it can be used to display peptides/proteins that are inhibitory to the secretion process and cannot be displayed in the M13 system. In addition, T7 phage can be produced very rapidly, which saves a lot of time and facilitates research.

Phage Display Peptide Library Technology:

The phage display peptide library belongs to the biosynthetic peptide library, in which an infectious filamentous phage is used as a vector and a fragment of a synthetic random DNA sequence is inserted into the gene encoding the shell protein of the vector by genetic engineering. The peptide encoded by this exogenous DNA fragment can be displayed as a fusion protein together with the phage shell protein on the surface coat of a live phage, in addition, maintain relatively independent spatial conformation and biological activity without affecting the ability of this recombinant phage to infect the host bacterium. Only one exogenous random peptide can be displayed on the surface of each phage viral particle, and the collection of all phages displaying different peptides constitutes the phage display peptide library. The constructed phage display peptide library is affinity screened by the target protein (e.g., monoclonal antibody) and then enriched for those recombinant phages that bind to the target protein (i.e., the corresponding phage antigenic peptide). Such phages exhibiting antigenic peptides can proliferate in E. coli. So once a recombinant phage exhibiting a specific peptide is obtained, then this phage can become an unlimited source of specific peptides.

The main advantage of phage display peptide library is their low cost, the ability to amplify them in vitro, and the ability to obtain large numbers of target phage peptides simply and rapidly. Theoretically, a phage display peptide library can be screened for any desired peptide sequence from it if it is large enough, and it is possible to screen for certain sequences that simply do not exist in nature.

Fig.2 Principle and procedure of peptide library construction 

Application of Phage Display Peptide Library Technology:

--Screening of biologically small active peptides such as enzyme inhibitors, receptor activators or antagonists

--Research on antigen epitope structure, mechanism of action, etc.

--Research on synthesis of artificial antibodies

Advantages of KMD Bioscience:

--High throughput production of customised peptide libraries constructed by KMD Bioscience.

--High specificity, high sensitivity and accurate localisation of antigenic determinants.

--Professional technical experts to guide you throughout the whole process.

--Provide accurate and fast solutions to save your time.

--Phage display technology platform: provide you with dozens of premade peptide library screening services.

Related Products:

With our rich experience and professional phage display technology platform, you can choose our products without hesitations and we can also provide phage library screening services. Please feel free to call our sales manager for technical information and a quotation!