Creative BioMart screens a large number of MHC-associated peptides for a few key bioactive peptides in biological studies, which is a powerful tool for discovering T cell epitopes and MHC binding sites. As an industry leader in peptide library technology, we have many years of experience in designing and synthesizing custom peptide libraries.

Introduction of Peptide Library

Peptide library can be used for linear or continuous epitope mapping and to determine which part of a given protein or peptide contains the essential amino acids that contribute to its function. MHC peptide library is characterized by two parameters, peptide length and number of offsets, each library is generated by dividing the original protein or peptide into a number of overlapping peptides of equal length. The optimal MHC-associated peptide length is between 8 and 20 amino acids and, as a general guideline, the peptide must be at least 6 residues long to cover an epitope. The offset number is the number of amino acid residues shared by adjacent peptides and it reflects the degree of overlap.

The selection of the appropriate MHC-associated peptide length and offset number depends on the application of the peptide and also affects the cost of the peptide set and the usefulness of the data obtained from the experiment. Longer peptides will yield more epitope hits per peptide, but they are harder to synthesize and the library will contain fewer peptides. Shorter peptides are easier and less expensive to synthesize, but will result in fewer epitope hits per peptide. The combination of low offset number and short peptide length produce the greatest number of peptides, while the combination of high offset number and long peptide length produces the least number of peptides.

Fig.1 Peptide library and MHC alignment. (Sospedra M, 2002)

Our Designed MHC-associated Peptide Library

Our peptide library technology can be used for many different types of libraries.

• Overlapping peptide library

We provide the overlapping peptide library approach employing the selection of putative T-cell epitopes, which is based on predicted binding to certain major histocompatibility complex (MHC) molecules and peptide or protein libraries.  They generated in expression, positional scanning of synthetic and soluble combinatorial peptide libraries allowing the identification of T-cell epitopes in complex protein mixtures.

• Truncation library

Our truncated libraries are analyzed and show that certain amino acid residues appear at specific positions in peptide sequences bound to a given MHC molecule. These sequence motifs require shifting the amino terminus by one or two positions to obtain a comparison; this shift occurs naturally for individual peptide sequences and does not alter T cell recognition

• Random library

We apply the random library by using synthetic random peptide libraries of different lengths (e.g., 7-15 amino acids) for temperature-dependent peptide stabilization assays. And our analysis can determine successful stabilization, ultimately revealing different length preferences for peptides bound by different MHC molecules.

Applications

• Scanning for epitopes of antigenic sequences
• T-cell stimulation in T-cell assays
• Screening of substrates for MHC proteins
• Mapping antibody epitopes
• Identification of T-cell epitopes
• Discovery of additional binding sites in MHC proteins
• Determination of the interaction of MHC proteins with receptors

Turnaround Time

The project cycle for peptide library design depends on your custom requirements. Our technical and application support team can provide advice on experimental design and analysis. In terms of design.

Creative BioMart offers a variety of options for optimal overlap or offset of peptides to be used in your target application. For applications such as ELISPOT, cell culture, intracellular cytokine staining, and flow cytometry, experimental designs and detailed analytical reports are available. If you are interested in our services, please contact us for more detailed information.

Reference

• Sospedra M, et al. (2002). Use of combinatorial peptide libraries for T-cell epitope mapping. Methods. 29(3): 236-47