Analysis of Glycopeptides of Monoclonal Antibody Using MALDI-7090 High-Resolution MALDI-TOF MS

Introduction

Antibodies that are utilized in biopharmaceuticals are often subjected to glycan modification. This glycan is a molecule with high structural heterogeneity consisting of intricately coupled monosaccharides, such as glucose and mannose, and that complex structure is known to play an important role in the functional regulation of proteins. However, information such as the complex structure of the glycan and the site at which the glycan is attached to the protein is not written into the gene beforehand. Rather, it is information that is formed based on the actions of many glycosyltransferases during the process of protein biosynthesis. Therefore, depending on the state of growth of the cells that produce antibodies, it is not uncommon to see such phenomena as the formation of glycans having different structures in spite of the same protein backbone, or the formation of the glycan bond at an unexpected site. Therefore, when an antibody is biosynthesized as a biopharmaceutical, elucidation of both its structure and binding site is important. Mass spectrometers are now regularly used for ascertaining both the binding site as well as the structure of glycans. Here, using the MALDI-7090 high-resolution MALDI- TOF MS with its unique 20 keV high energy fragmentation capability, we introduce an example of analysis to determine the structure and binding site of a glycan bound to an antibody.

February 15, 2016 GMT