Peptide Mapping road leads to
Lancaster Labs

Peptide mapping, a powerful tool for identifying proteins, is among the new tests being performed by the analysts in the Biopharmaceutical Services Group at Lancaster Laboratories. The technique, which typically involves the use of an enzyme to cleave the protein, followed by chromatographic separation of the resulting fragments, is applicable to many types of products from raw materials through final release. Several methods of detection are available depending upon the application. For example, to determine peptide fragment identity, a high performance liquid chromatograph (HPLC) separates the complex digest mixture so that exact mass determination can be made of individual fragments using an electrospray-ionization mass spectrometer time-of-flight (ESIMS-TOF). The resulting peptide map is unique to the protein, almost like a fingerprint.
Dr. Bob Duff, principal biochemist in Lancaster Labs’ Biopharmaceutical Group, operates the ESIMS-TOF.
“Clients are interested in peptide mapping because the FDA recognizes the technique as extremely useful for protein characterization,” says Dr. Robert J. Duff, a principal biochemist at Lancaster Labs. He cites the sensitivity of the technique, which can sometimes detect as low as the femtomole level, as one of the advantages of peptide mapping using mass spectrometry. Some of the challenges of method development include selecting an appropriate cleaving agent and optimizing the chromatography to separate the resulting peptides.

Biochemists at Lancaster Labs also have experience with a number of other techniques used for protein characterization, such as sequencing using HPLC with ion trap mass spectrometry, biochromatography analysis, amino acid analysis, and enzymatic activity determination.

For more information, please call Pharmaceutical Business Development at (717) 656-2300.