In Vitro Sialylation of Recombinant Alpha-1-Antitrypsin using α2,6 Sialyltransferase from Photobacterium Damselae Produces Di-sialyl Galactose Motifs in N-Glycans

07 June 2019, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Sialic acids are cell surface sugars present in many animal glycoproteins and are of particular interest in biopharmaceuticals, where lack of sialylation can reduce bioactivity. Here we describe how α-2,6-sialyltransferase from Photobacterium Damselae can be used to markedly increase sialylation of CHO produced alpha-1-antitrypsin. Detailed analysis of the sialylation products showed that in addition to the expected α-2,6-sialylation of galactose, a second di-sialyl galactose motif was produced, which had never been recorded on a mammalian glycoprotein. The influence of this unique di-sialylation on the in vitro activity of alpha-1-antitrypsin was studied and a toolkit of mass spectrometry methods to identify this new di-sialyl galactose motif in complex mixtures was developed


Glycan Remodeling
Sialic acid
Di-Sialyl Galactose
Alpha-1-Antitrypsin Deficiency
Mass Spectrometry
Ion Mobility
Increasing Sialylation
Photobacterium Damselae

Supplementary materials

pre-print supporting info


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