TABLE 3.
Mutarotase activities in L. lactis IO-1, L. lactis 210, and L. lactis NRRL B-4449 and of overexpressed L. lactis 210 XylM purified from recombinant E. coli BL21
| Sample | Mutarotation ratea(R2) | Enzymatic mutarotation (U)b | Specific mutarotase activity (U/mg of protein) |
|---|---|---|---|
| L. lactis 210 lysate | 5.12 (0.66) | 0 | 0 |
| Xylose standard (spontaneous) | 5.13 (0.92) | ||
| L. lactis IO-1 lysate | 9.08 (0.87) | 2.34 | 2.9 |
| Xylose standard | 6.74 (0.93) | ||
| L. lactis NRRL B-4449 lysate | 5.93 (0.93) | 1.03 | 0.9 |
| Xylose standard | 4.90 (0.98) | ||
| L. lactis NRRL B-4449 glucose-grown lysate | 4.81 (0.95) | 0.13 | 0.1 |
| Xylose standard | 4.67 (0.97) | ||
| Overexpressed crude XylM | 7.59 (0.93) | 1.16 | 38.7 |
| B21 control | 6.43 (0.94) | ||
| Purified XylM | 9.66 (0.94) | 2.68 | 67.0 |
| Xylose standard | 6.98 (0.98) |
a
Mutarotation rate is the change in the relative beta peak height per minute.
b
Enzymatic mutarotation is the sample rate minus the spontaneous rate.