Primary Structure Characterization

Protein is not just a simple sum of its amino acids. In the study of proteins in drug development, the first most necessary and critical step you take is to analyze their primary structure.

Our scientists are proficient in today's most important techniques for analyzing primary structures, using a number of independent but interrelated analytical techniques to provide detailed descriptions of the primary structures, including sequence-based intact mass confirmation, amino acid sequence confirmation, N- and C-terminal variants as well as disulfide structures.

Overview of Our Services

Services	Techniques
Intact Mass Confirmation	Native, deglycosylated, and reduced protein electrospray ionization-mass spectrometry (ESI-MS)
Amino Acid Sequence Confirmation	MS/MS sequencing of peptide maps
N- and C-terminal Variants	MS/MS sequencing of peptide map
N- and C-terminal Sequencing	De novo antibody sequencing
Disulfide Structure	Non-reduced and reduced peptide map with MS Ellman’s assay (or similar)

A combination of molecular mass spectrometry (MS) and peptide mapping analysis to determine the peptide's primary structure (amino acid sequence) is not only a regulatory requirement for ICH Q6B, but also a powerful tool of understanding how to modify the protein to meet your goals.

According to the requirements of ICH Q6B, the intact mass of the protein needs to be given. Full quality analysis is used to determine the identity and integrity of the protein. When combined with the results of other analyses, it also becomes a tool of better understanding the whole protein structure.

De novo sequencing is performed when the sequence of the protein is not available in the open protein or genomic database. It requires experienced professional scientists to carry out difficult manual operations.

N/C-terminal sequencing is a key part of ICH Q6B, which indicates the "property and homogeneity" of proteins identified by the N- and C-terminal amino acids.

Disulfide bonds are also a key part of ICH Q6B. We can choose two methods, one of which is more suitable for your specific needs.

Feel free to contact us for project quotations and more detailed information.