Table 2. Specific activity comparison of CpXyn30A and BsXynC on xylans and xylooligosaccharides.
Specific activity is given in units per milligram of protein, where one unit of activity is defined as one µmole per minute. The data resulted from triplicate measurements from a single assay. These results were consistent with numerous previous analyses. The given error is represented by the standard deviation.
| Substrates | Concentration | CpXyn30A | BsXynC |
|---|---|---|---|
| Sweetgum glucuronoxylan (SGX) | 10.00 mg ml−1 | 1.1 ± 0.1 | 70.7 ± 4.8 |
| 7.50 mg ml−1 | 1.1 ± ≤0.1 | 61.7 ± 3.8 | |
| Wheat arabinoxylan (WAX) | 7.50 mg ml−1 | 1.7 ± 0.2 | nd† |
| Xylohexaose‡ (X6) | 12.10 mM | 1.19 ± ≤0.01 | 0.019 ± ≤0.002§ |
| Xylopentaose‡ (X5) | 12.10 mM | 0.36 ± ≤0.01 | ND¶ |
Not detected.
The data for these substrates represent an evaluation of specific activity based solely on the decrease in substrate. These values are higher than the true specific activity as the described competing transglycosylation reaction presumably consumes two X6 molecules. Xylohexaose was digested for 8 min and xylopentaose was digested for 20 min.
The X6 substrate concentration was only 10 mM for this reaction, a difference in the comparison which is considered to be inconsequential for this study.
Not determined.