A comparison between analytical approaches for molecular weight estimation of proteins with variable levels of glycosylation.

Amita Puranik, Marianne Saldanha, Prajakta Dandekar, Ratnesh Jain

Electrophoresis 2022 Jun

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Biotherapeutics, such as mAbs and fusion proteins, are a major and rapidly growing class of pharmaceuticals. Majority of the biopharmaceuticals are glycoproteins, wherein about 1 to 30% of their molecular weight (MW) are contributed by the glycans. Determination of MW of heavily glycosylated proteins, such as Fc-fusion proteins, is seriously hampered by the physicochemical characteristics and heterogeneity of the attached carbohydrates. Glycosylation influences the expected size of the glycoprotein, which leads to disproportionate MW estimation, in size-dependent methods. Hence, in this study, we have demonstrated the advantages and limitations of four widely used MW estimation techniques for three proteins having varying levels of glycosylation. It was proven that glycosylation had least impact on MW determination by SEC-MALS and SV-AUC. However, MW estimation by LC-MS and SDS-PAGE was extensively hampered by the degree of glycosylation. It is, thus, essential to consider the structural characteristics of proteins while selecting a technique for determining their MW. © 2022 Wiley-VCH GmbH.

Citation

Amita Puranik, Marianne Saldanha, Prajakta Dandekar, Ratnesh Jain. A comparison between analytical approaches for molecular weight estimation of proteins with variable levels of glycosylation. Electrophoresis. 2022 Jun;43(11):1223-1232