Due to in vivo processing and post-translational modifications, the N- and C-terminus of a protein are generally not predictable from its gene sequence, and heterogonous N- termini and/or C-termini may be present in a therapeutic protein product. Therefore, it is required by ICH Q6B guidelines and FDA “well characterized” concept to characterize the N- and C-terminus of a therapeutic protein product.

ProtTech provides a service for characterizing the N- and C-terminus of therapeutic proteins and antibodies. Our Peptide Mapping service is capable of identifying and sequencing protein N- and C-termini by MS/MS, even in the cases where heterogeneous N- or C-termini are present. Under request, we can also carry out Edman sequencing and report the first 7 amino acids in the N-terminus of a protein. There is currently no established chemical sequencing method for protein C-terminus. In the cases where our peptide mapping service can’t conclusively identify a protein’s C-terminus, we use the O-18 labeling method that can specifically identify and sequence protein C-terminus.

• Protein Mixture Quantitation & Impurity Analysis

• Peptide Mapping

• Disulfide Bond Analysis

• Glycosylation Analysis

• Intact Molecular Weight Measurement

• Electrophoresis and Isoelectric Focusing Analysis

• Liquid Chromatographic Analysis

• Colony Selection

• Antibody Epitope Mapping

• Identifying Antibody Molecular Targets

• De Novo Sequencing of mAb

• Software for Characterizing Therapeutic Proteins

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