Applications for MALDI & Q-TOF
A Study on a Method for Evaluating Glycans in Biopharmaceuticals
Many protein-based biopharmaceutical products, typified by antibody drugs, are synthesized in cultured cells derived from eukaryotes such as CHO (Chinese hamster ovary) cells. For this reason, there are inevitably many post-translational modifications to the biosynthesized proteins. Among these, modifications of glycans have gained attention as items for evaluating the quality of biopharmaceuticals since they are associated with the adjustment of protein functions, as well as with the unwanted development of antigenicity depending on their structure. However, there are various technical challenges in evaluating glycans.
Analysis of Glycopeptides Using MALDImini 1 Compact MALDI Digital Ion Trap Mass Spectrometer
Glycans, which are one post-translational modification of proteins, are molecules with high structural heterogeneity which are formed by complex bonding of glucose, mannose, and other monosaccharides. It is known that their complex structure is related to regulation of protein functions, and various phenomenon can be observed depending on illness and other factors. These include abnormal glycan structures with the protein backbone and the absence of glycan bonding at sites where it is assumed that such bonding should occur. The information concerning complex glycan structures and the binding sites of glycan with the proteins is not coded directly in genes but is created by the action of a large number of glycosyltransferases, which act in the protein biosynthesis process.
Analysis of N-Linked Glycan using MALDImini 1 Compact MALDI Digital Ion Trap Mass Spectrometer - Structural Analysis and Identification of Sialyl Linkage Isomers
N-linked glycosylation to proteins plays an important role in various biological phenomena. In particular, sialic acids existing at sugar chain terminals and their linkage types are known to be key factors related to numerous diseases, such as antigenicity and viral infections. In recent years, mass spectroscopy (MS) has been widely used in glycan analysis. However, there were various problems related to sialic acid residues, in that they are unstable and thus easily lost while analysing, and furthermore, it is not possible to differentiate linkage isomers by MS. On the other hand, HPLC analysis is mainly used to identify the linkage type of sialic acids, but this method also has technical problems, for example, identification is difficult in the case of glycans with numerous sialic acids.