Types of peptide libraries

Alanine Scanning Library
    The Ala scanning peptide library is a method for identifying the effects of specific amino acids in a sequence on peptide function. We sequentially replace the amino acids in the sequence with Ala; through the Ala scanning peptide library, the impact of specific amino acids on the overall protein structure, function, and other biological activities can be identified.

Positional Scanning Library (PSL)
    A positional scanning peptide library is an important tool for optimizing peptide sequences. It systematically substitutes other amino acids for selected regions or sites of a peptide and determines the optimal amino acids at these sites through peptide activity assays. This type of peptide library helps researchers identify specific regions that have particular effects or activities at specific positions.

Overlapping Library

The overlapping peptide library is a common method for screening linear or continuous epitopes. The design of the peptide library is mainly determined by two parameters: peptide length and offset number. As the protein is truncated from the N-terminus to the C-terminus, it is possible that an orphan peptide may be left at the end. To maintain consistent length, we recommend shifting one or several amino acids from the N-terminus.

Truncation Peptide Libraries

Truncation peptide libraries are used to identify the shortest amino acid sequences within a peptide sequence. The construction of truncation peptide libraries typically involves systematically removing amino acids from both ends of the original peptide sequence. If certain important amino acids are known, these amino acids should be retained, and amino acids are then removed one by one from the other end of the peptide to begin screening.

Random Peptide Library

Random peptide libraries are designed via a shotgun approach to include the 20 natural amino acids, while simultaneously randomly substituting selected amino acid residues.

Scrambled Library

The design of scrambled libraries is based on internal rearrangements of the original peptide amino acid sequence. It is the peptide library with the highest degree of mutation. Disrupted peptides are often used as negative controls to demonstrate that specific sequences are critical for protein function or activity. It is also a random screening tool used to identify new targets.