Custom Peptide Library Services

Peptide Library General Information

Peptide library applications

A peptide library is a new technique for studying structure-function relationship for a protein. A peptide library contains a great number of peptides that have a systematic combination of amino acids. The peptide library provides a powerful tool for drug design, protein-protein interactions, and other biochemical as well as pharmaceutical applications. It also has wide applications in drug screening, target validation, epitope mapping, and vaccine development. Some other applications of peptide library are:

  l Receptor (GPCR) ligand screening

  l Peptide Drug discovery

  l Protein-Protein interaction

  l Functional proteome

  l Peptide-Nucleic acid binding

  l Enzyme substrate or Peptide-Inhibitor screening

  l Antigen binding sites or epitope mapping

  l T-Cell epitope disovery

  l Antoantibody binding sites on antigens (protein)

  l Antibody cross reaction with a related protein family member

  l Identification of small peptides as vaccine candidates

Peptide library specifications

At BeijingSBS Genetech, peptide library is usually supplied as either desalt or >70%, >80%, >90%, and >95% purities). Peptides can be made in required amounts from minimal to mg scale for initial screening. Appropriate peptide labels (Biotin, FITC, etc.) can be added upon request. Each peptide in the library undergoes rigorous quality control to avoid any cross contaminants before delivery. All purified peptides are delivered with complete QC data including RP-HPLC, MS, and COA report to ensure high quality. The desalted peptides are provided with MS only. Peptide length in a given library is usually 5-15 aa with 1-5 amino acid overlap.

Peptide library types

Depending upon a given application, peptide libraries are usually defined as:

A. Overlapping Peptide Library

Overlapping peptide library can be used for epitope mapping. The peptide length (5-15aa) and offset number or the degree of overlapping amino acids (2-5 aa) is determined by the length of the full length proteins, overall experiment objectives and the cost. As a general guideline, shorter peptides have less chance for multiple epitope hits. Greater degree of overlapping (small offset number) gives more chances of multiple epitope hits.

Example:   (peptide length 10 aa, offset/overlap 3 aa)

       DSTRKLMNRT QSEDKLPSRG QHTRSDKENN PSSTRGHLED (30 aa protein)

       DSTRKLMNRT                                      Peptide #1

               RKLMNRTQSE                              Peptide #2

                      MNRTQSEDKL                       Peptide #3

                                TQSEDKLPSR              Peptide #4

Total peptides, n=11

B. Alanine Scanning Library

Example:   (peptide length 10 aa)

       DSTRKLMNRT                                    Peptide #1

       ASTRKLMNRT                                    Peptide #2

       DATRKLMNRT                                   Peptide #3

       DSARKLMNRT                                   Peptide #4

       DSTAKLMNRT                                    Peptide #5

       DSTRALMNRT                                    Peptide #6

       DSTRKAMNRT                                    Peptide #7

       DSTRKLANRT                                     Peptide #8

       DSTRKLMART                                    Peptide #9

       DSTRKLMNAT                                    Peptide #10

       DSTRKLMNRA                                    Peptide #11

C. Truncation Library

Truncated peptide library can be used to identify the shortest amino acid sequence needed for a given function or activity.  

Example:   (peptide length 10 aa) Truncation from the N-terminus

       DSTRKLMNRT                                 Peptide #1 (control peptide with full function)

          STRKLMNRT                                Peptide #2

            TRKLMNRT                                Peptide #3

              RKLMNRT                                Peptide #4

                 KLMNRT                                Peptide #5

                    LMNRT                               Peptide #6

                      MNRT                               Peptide #7

 Truncated peptides can also be generated from the C-Terminus.

D. Random/scrambled Library

Scramble Library is constructed by carrying out permutation on the original peptide’s sequence. The number of each amino acid (e.g. 2 Arg or R) is the same in the peptide except its position and other amino acids are created at random. This strategy is used for preliminary identification of a group of active sequences that may possess a given function or activity.

       DSTRKLMNRT              Peptide #1 (control peptide with full function)

       TRLKSTNRMD              peptide # 2

       RSTRLDMNKD              peptide # 3  etc

E. Positional Scanning Library

A selected position or positions in a peptide sequence are each systematically replaced with all other natural amino acids (20) or any other amino acid to determine the preferred amino acid residues at a given position that will maximize the peptide activity.

Example:   peptide length 10 aa, with substitution of “K at position 5.

       DSTRKLMNRT                      Peptide #1 (control peptide)

       DSTRALMNRT                      Peptide #2

       DSTRCLMNRT                      Peptide #3

       DSTRDLMNRT                      Peptide #4

       DSTRELMNRT                       Peptide #5

       DSTRFLMNRT                       Peptide #6

       DSTRGLMNRT                      Peptide #7

Potential peptides =20 with all 20 natural amino acids. It is also possible to study the replacement of “N” at position #8.

Peptide Library Pricing

Peptide libraries are synthesized on SBS Genetech’s unique proprietary synthesis platform and are typically supplied at the 2-4 mg scale for fast, efficient screening work.  

Peptide library pricing (per peptide) for up to 15 amino acids.

l Desalted peptides are provided with MS only.

l Purified peptides are provided with MS and HPLC data.