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Table 5 Para-nitrophenyl release by TrCel7A or TrCel7A core from pNP-lac at 50°C and 30°C in the presence of phosphoric acid swollen cellulose

From: Xylan oligosaccharides and cellobiohydrolase I (TrCel7A) interaction and effect on activity

Enzyme, temperature substrate Control 1 g/L low XOS 1 g/L high XOS
TrCel7A core, 50°C
pNP-laca (PASC)
25 ± 2 μM pNP
20% of total activity
15 ± 4 μM pNP
12% of total activity
9 ± 1 μM pNP
8% of total activity
TrCel7A, 50°C
pNP-lac (PASC)
6 ± 1 μM pNP
7% of total activity
5 ± 1 μM pNP
5% of total activity
< 4 μM pNPb
TrCel7A core, 30°C
pNP-lac (PASC)
6 ± 1 μM pNP
12% of total activity
< 4 μM pNPb < 4 μM pNPb
TrCel7A, 30°C
pNP-lac (PASC)
< 4 μM pNPb < 4 μMb < 4 μM pNPb
  1. PASC = phosphoric acid swollen cellulose; pNP = para-nitrophenyl; pNP-lac = para-nitrophenyl-β-D-lacoside; TrCel7A = cellobiohydrolase I; XOS = xylan oligosaccharide. The percentages were calculated on the basis of the total pNP activity shown in Table 3. The deviations are the standard deviations of five independent experiments. aThe Ki for cellobiose in the pNP-lac assay is 20 μM, which is exceeded here. The activities are underestimated. bThe detected absorbance changes were below 0.02 absThe activities were too low for reliable quantification.