The glycosylation reactions were carried out in standard conditions using single (N1348Q, N1352Q, N1366Q) mutants of His-HMW1ct as acceptor proteins and UDP-glucose as donor substrate. (A) After the glycosylation reaction, the samples were separated by SDS-PAGE, and the gel was stained with Coomassie Blue. (B) A duplicate gel was transferred to a PVDF membrane and subjected to a detection reaction using the GlycoProfile III Fluorescent Glycoprotein Detection kit (Sigma). The lanes labeled “Native” and “His-HMW1ct only” are control reaction samples with and without ApHMW1C, respectively. M1 is a pre-staining protein marker (Precision Plus Protein Standards, Bio-Rad), and M2 is a glycosylated protein marker (ProteoProfile PTM Marker, Sigma).