Therapeutic Peptide Library

Overlapping libraries are ideal tools for screening linear or continuous epitopes. The purpose of this technology is to generate overlapping peptide sequence libraries. Each peptide library is determined by peptide length and peptide offset, which means that each peptide in the peptide library will have the same peptide length but different primary structures according to the offset. The peptide offset defines the number of overlapping amino acid residues between two adjacent sequences and corresponds to the degree of overlap. The combination of low offset and short peptides can form the largest number of peptides, while the combination of high offset and long peptides can produce the least number of peptides.

Alanine (Ala) scanning peptide library is used to determine the effect of a specific amino acid on the function, activity, or stability of the peptide structure. The library is designed by replacing each non-alanine residue with alanine in sequence. Replacing key residues with Ala results in decreased peptide activity and indicates the importance of the replaced residue in the overall structure. Therefore, Ala is used to distinguish the effect of a specific amino acid on the biological activity of the entire protein and is also used to evaluate the functional activity of enzymes and study the binding sites of proteins.

The truncation library is a technique used to find the shortest amino acid sequence required for epitope activity. The library is established by continuously removing the flanking residues of the original polypeptide. If the essential amino acids are known after Ala scanning, the truncation path can be customized to remove the residues at the other end of the peptide. In some cases, the so-called truncated peptide library is used to amplify the screening process and isolate the most stable peptides that are not easily degraded by proteolysis. In addition, it can also be used to study the degree of metabolic degradation of peptide drugs. It can also be used to obtain the most epitope sequences and the best binding sites for proteins.

Scrambled Library is often used to optimize peptide sequences. This library is constructed based on the alteration of the original peptide sequence, which means that all amino acid residues of the initial sequence are mixed together to form all possible amino acid combinations. Scrambled library is the most variable of all peptide libraries, showing all possible peptide substitution structures, and is a tool for finding new clues by creating random screening libraries. They are often used as targeted molecular probes for proteins, antibodies, genes, etc.

Positional scanning library is particularly useful for peptide sequence optimization, which is generated by replacing one or more selected residues in the peptide sequence with all other natural or unnatural amino acids. This library can be used to identify amino acids that increase activity or binding and design sequences with improved properties. Additionally, it can also be used to identify and improve T cell epitopes or antibody epitopes from complex protein mixtures.

Random library is used to optimize peptide sequences or generate new active peptide sequences. This peptide library is obtained by randomly and spontaneously replacing all or part of the selected sites with 20 natural amino acids using a shotgun method. It is used for target identification, drug discovery, and peptide sequence optimization.