Table 2.
Enzyme activity of examined glycoside hydrolyses on para-nitrophenyl linked glycosides (pNP-substrates)
| Enzyme | Specific enzyme activity (U/mg) | |||||||
|---|---|---|---|---|---|---|---|---|
| para-Nitrophenyl- | ||||||||
| α-l-Arabinofuranoside | α-d-Glucopyranoside | β-d-Glucopyranoside | β-d-Galactopyranoside | α-l-Rhamnopyranoside | β-d-Xylopyranoside | β-d-Glucuronide | N-acetyl-β-d-glucosaminide | |
| Bga2B | – | – | – | ++ | – | – | – | – |
| Bga2E | – | – | – | + | – | – | – | – |
| Bga2D | – | – | – | + | – | – | – | nt |
| Bga2C | – | – | – | ++ | – | – | – | nt |
| Uid2A | (+) | – | + | + | – | (+) | +++ | nt |
| Bxl3B | ++ | – | + | – | – | +++ | – | – |
| Bgl3Z | + | (+) | +++ | + | – | +++ | – | – |
| Nag3A | – | – | – | – | – | – | +* | + |
| Xyn10E | – | – | – | (+) | – | (+) | – | nt |
| Xyn10C | (+) | – | (+) | – | – | + | – | nt |
| Xyn10B | (+) | – | (+) | (+) | – | ++ | – | nt |
| Xyn10D | – | – | – | – | – | (+) | – | nt |
| Bxl31D | – | – | – | – | – | + | – | nt |
| Bxl39A | + | – | – | – | – | + | – | nt |
| Axh43A | ++ | – | – | – | – | – | – | nt |
| Arf43A | (+) | – | (+) | – | – | ++ | – | nt |
| Arf43C | ++ | – | – | – | – | (+) | – | nt |
| Abn43A | (+) | – | – | – | – | – | – | nt |
| Xyl43B | – | – | – | – | – | + | – | nt |
| Xyl43A | (+) | – | – | – | – | (+) | – | nt |
| Bxl43C | + | – | – | – | – | ++ | – | nt |
| Arf51B | ++++ | – | – | – | – | + | – | nt |
| Ram78A | (+) | – | + | – | +++ | – | – | nt |
| Xyn105F | – | – | – | (+) | – | – | – | nt |
| RamB | – | – | – | – | (+) | – | – | nt |
| BglA | – | – | + | – | – | (+) | – | nt |
| ArfD | + | – | (+) | + | – | – | – | nt |
Hydrolysis experiments were performed in triplicates at pH 6.5 and 60 °C in 0.1 M MOPS reaction puffer for incubation times between 10 min and up to 2 h. Enzyme activity was determined by spectrophotometric detection of released pNP. No activity was detected for 22 of 49 enzymes (not listed). Gal53A was not tested. Tested aryl-glucosides with no activity were: pNP-α-d-galactopyranoside, pNP-α-d-mannopyranoside, pNP-β-d-mannopyranoside, and pNP-α-d-xylopyranoside. Substrate was not tested (nt), incubation overnight (*), detectable but very low activity ((+)), 0.05–0.5 U/mg (+), 0.5–5.0 U/mg (++), > 5.0 U/mg (+++), > 100.0 U/mg (++++)