MedImmune’s focus is on therapeutic proteins, monoclonal antibodies and other next-generation molecules to attack a range of diseases in order to place them at the forefront of biologics research and development.
BioPharmaSpec performed N-terminal sequencing analysis of minor and major bands observed on SDS-PAGE gels from various protein samples. The analysis successfully identified the N-termini of the components and provided crucial information regarding sites of truncation. The project was later extended to include analysis of further samples following liquid formulation, which was further contributing to the truncation issues.
Technical Considerations - Edman Chemistry
Automated N-terminal sequencing uses Edman chemistry which requires a free amino functionality at the N-terminus of a protein for labeling prior to cleavage of the N-terminal and subsequent amino acids. This means that for a number of monoclonal antibodies (which have a Pyroglutamic acid at the N-terminus and therefore no free amino group), N-terminal sequencing using this method will not provide sequence information. In this case, BioPharmaSpec used Pyroglutaminase to enzymatically remove the N-terminal Pyroglutamic acid residue prior to N-terminal sequencing.
“This was a fairly complex study, complicated by the sensitivity required to achieve useful data. We approached BioPharmaSpec after some other options had failed and were very pleased with how they used their technical expertise to achieve the sensitivity required and provide us with good data.” – Bioanalyst, MedImmune