Table 3.
Substrate | UDP-Gal |
UDP-Gal hydrolysis |
UDP-GalNAc |
|||||
---|---|---|---|---|---|---|---|---|
KAa (μM) | KBb (μM) | kcat(s−1) | Km (μM) | kcat (s−1) | KAa (μM) | KBb (μM) | kcat (s−1) | |
– 15 GTB (amino acids 68–354) | 55±13 | 45±6 | 7.3±0.7 | 47±20 | 0.0022±0.0002 | 300±55 | 145±20 | 0.41±0.04 |
GTB/C80S/C196S | 32±6 | 23±6 | 5.6±0.4 | 22±9 | 0.0027±0.0003 | 300±70 | 210±40 | 0.70±0.02 |
GTB/C89S/C196S/C209S | 350±80 | 78±13 | 8±1.0 | 120±40 | 0.0012±0.0001 | 200±40 | 320±70 | 0.15±0.03 |
KA is the Michaelis-Menten constant Km for the acceptor [Fucα1–2Galβ-O-(CH2)7CH3].
KB is the Michaelis-Menten constant Km for the donor (UDP-Gal or UDP-GalNAc).