Abstract
Arabinogalactan proteins (AGPs) are plant-specific extracellular glycoproteins regulating a variety of processes during growth and development. AGP biosynthesis involves O-galactosylation of hydroxyproline (Hyp) residues followed by a stepwise elongation of the complex sugar chains. The initial Hyp O-galactosylation is mediated by Hyp O-galactosyltransferase (HPGT) that catalyzes the transfer of a D-galactopyranosyl residue to the hydroxyl group of Hyp residues of peptides from the sugar donor UDP-α-D-galactose (Figure 1). Here we describe a LC/MS-based method for the detection of HPGT activity in vitro.Figure 1. Reaction scheme for Hyp galactosylation by HPGT. HPGT catalyzes the addition of a D-galactopyranose from an UDP-α-D-Gal to the hydroxylgroup of Hyp residues.
Materials and Reagents
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Acknowledgments
This is the detailed protocol for the detection of HPGT activity described by Ogawa-Ohnishi and Matsubayashi (2015). This research was supported by a Grant-in-Aid for Scientific Research (S) from the Ministry of Education, Culture, Sports, Science, and Technology (No. 25221105).
References
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