Terminal AA Sequencing

The N and C-terminal aminoacid sequence is an important quality control for biopharmaceutical products included in the ICH Q6B section 6.1.1c.In biopharmaceuticals, is important to confirm that the sequence of the terminal aminoacid is identical to the terminal aminoacid sequence deduced from the genetic sequence and confirm that the protein termini are identical from batch to batch.

An incomplete processing of the protein N-terminal signal sequences, the retain of the initiation methionine at the amino-terminal end which affects to the immunogenicity of the protein, acetylation or pyroglutamic acid from protein N-terminal Glu and Gln residues are often observed variation in the N-terminal.

Common variation of the C-terminal is the sequence truncation due to the removal of the C-terminal Lys residue of the heavy chain in monoclonal antibodies. 

AMSbiopharma provides an N-terminal sequencing service (Edman sequencing). In Edman sequencing, the peptide bonds are sequentially hydrolysed from the N-terminus, and the released aminoacids are identified by HPLC-MS analysis.

Because there is no standard approach to confirm the C-terminal aminoacid sequence, AMSbiopharma offers to our clients a strategy based on the combination of the following analysis:

• Peptide mapping

• HPLC-MS/MS peptide sequencing

• Molecular weight analysis

Jointly analyzing all the information provided by these methods, can be obtained the C-terminal AA sequence of your biopharmaceutical.