FIGURE 5.

Effects of lectin domains on dC1GalT enzyme activity. A, dC1GalT activity was assayed without (pink) or with 0.08 μm T2lec (blue), T3lec (green), and T4lec (orange). Error bars represent S.D. of three independent experiments. B, dC1GalT activity was assessed in the absence (black) and presence (green) of 0.08 μm T3lec with dOSM as acceptor substrate using non-linear fitting that yielded R² values of 0.98 (black) and 0.96 (green). Data are representative of three independent experiments. C, double reciprocal plot of dC1GalT activity, demonstrating the activation ability of T3lec, with R² values of 0.91 (black) and 0.89 (green) from linear regression fitting. D, Gal-T activity of dC1GalT with OSM as acceptor substrate in the absence (black) and presence of 0.16 μm ppGalNAc-T3 (yellow), yielding R² values of 0.99 (black) and 0.99 (yellow) by non-linear fitting software. Control, Gal-T activity of 0.16 μm ppGalNAc-T3 (blue) without dC1GalT. Results are representative of three independent experiments. *, p < 0.05; ns, not significant.