Intact Glycoform Analysis of Recombinant Enzyme Therapeutics Using Stepwise Enzyme Dissection and UHPLC/MS

다국어 초록 (Multilingual Abstract)

Agalsidase beta, recombinant enzyme therapeutic, which is a glycoprotein that treats lysosome accumulation disorders caused by deficiency of the enzyme alpha galactosidase A has 3 glycosylation sites(N108, N161, N184). In this protein, there are various glycans from acidic glycans to high mannose, so accurate monitoring is required for proper afficacy and function of drug. Recently, intact analysis is heavily used due to the advantage of simple preparation, short MS analysis time, glycan occupancy and micro-heterogeneity confirmation. However, numerous glycosylation sites, high molecular weight and glycan heterogeneity complicate the mass spectrum, making data interpretation and glycan assignment difficult. Here, we obtained the mass value of intact agalsidase beta, which eased the complexity of the mass spectrum by lowering the high molecular weight of the glycoprotein through stepwise enzymatic treatment. To facilitate the assignment of sialic acid and phosphorylated glycans at each glycosylation sites, deconvoluted spectra of sialidase and phosphatase-treated and untreated agalsidase beta were compared. Possible glycoforms could be assigned for each peak in the deconvoluted spectra within the accepted mass tolerance of ±5 Da. In the monomer and dimer structures of agalsidase beta, a glycosylation pattern was confirmed in which HexNAcNeuAc residues(494.1748 Da) and 2HexNAc2NeuAc residues (988.3496 Da) were increased, respectively. Our approach can be a efficient tool to confirm glycosylation pattern of therapeutic glycoproteins in biosimilar development.