Overlapping Peptide Libraries: What They Are and How to Design Them
What Is an Overlapping Peptide Library?
An overlapping peptide library is a collection of synthetic peptides designed to cover a protein sequence in a systematic way. Each peptide has a fixed length and overlaps with the neighboring peptide by a defined number of amino acids.
For example, a common design uses 15-mer peptides with 10 amino acid overlap. This means each peptide is 15 amino acids long and shares 10 amino acids with the next peptide. The sequence shifts forward by 5 amino acids each step.
Step size = Peptide length − Overlap
Example: 15 − 10 = 5 amino acid shift
Why Are Overlapping Peptide Libraries Important?
Overlapping peptide libraries provide complete and systematic coverage of a target protein or region of interest. They are widely used in:
- Epitope mapping to identify antibody-binding regions
- T-cell epitope screening for immunology research
- Variant comparison studies (wild-type vs mutation panels)
- Method development and validation
Because every part of the sequence is covered, overlapping libraries reduce guesswork and allow researchers to localize reactive regions efficiently.
How to Design an Overlapping Peptide Library
Designing a library involves several key decisions:
- Select the target region (full protein or defined segment)
- Choose peptide length (commonly 12–20 amino acids)
- Define overlap (higher overlap = higher resolution)
- Determine step size (length − overlap)
- Add controls or variants if needed
Higher overlap improves resolution but increases the total number of peptides. Lower overlap reduces cost but may decrease mapping precision.
Use Our Peptide Library Design Software
To quickly generate a formatted overlapping peptide list, use our Peptide Screening Tools:
https://www.biosyn.com/peptidescreeningtools.aspx
The software allows you to:
- Paste or upload your protein sequence
- Define peptide length and overlap
- Automatically generate the peptide list
- Export the design for ordering or screening
If needed, you can share your exported file with us and we can review the design and recommend the most efficient synthesis and screening format.