TABLE 2.
Michaelis-Menten constants of the recombinant HNK-1ST toward various substrates
Michaelis-Menten constant Km values of HNK-1ST were obtained from Lineweaver-Burk plots (supplemental Fig. 1), in which the reciprocals of initial velocities obtained by sulfotransferase activities of HNK-1ST were plotted against the reciprocals of varying concentrations of the substrates, Chn oligosaccharides, glucuronylneolactotetraosylceramide, and the linkage tetraosyl peptide. The sulfotransferase activities were quantified as described under “Experimental Procedures.”
| Substrate | Km |
|---|---|
| mm | |
| Chn octasaccharide (GlcUA-(GalNAc-GlcUA)3-GalNAc) | 2.6 |
| Chn hexasaccharide (GlcUA-(GalNAc-GlcUA)2-GalNAc) | 8.6 |
| Chn tetrasaccharide (GlcUA-GalNAc-GlcUA-GalNAc) | 2.3 |
| Glucuronylneolactotetraosylceramide (GlcUA-Gal-GlcNAc-Gal-Glc-ceramide) | 0.76 |
| GlcUA-Gal-Gal-Xyl-SGDNG | 0.024 |