Table II.
Activity of HEXO proteins and jack bean β-hexosaminidase (Sigma) with N-glycan and chitooligosaccharide substrates
Substrate (5 μm) was incubated with HEXO and jack bean enzymes in 0.1 m sodium citrate/phosphate buffer (pH 5.0) for different times at 30°C. The samples were then analyzed by reverse-phase HPLC. For GnGn-PA and GnGnXF-PA, the hydrolysis rates shown are derived from assays where less than 5% of the substrate was converted into MM-PA or MMXF-PA, respectively.
| Substrate | Products | Enzyme Protein (HEXO) or Total Protein (Jack Bean)
|
|||
|---|---|---|---|---|---|
| HEXO1 | HEXO2 | HEXO3 | Jack Bean | ||
| pmol min−1 mg−1 | |||||
| GnGn-PA | GnM-PA | 3.2 × 104 | 5.4 | 37.8 | 1.8 × 103 |
| GnGn-PA | MGn-PA | 2.6 × 103 | 0.7 | 9.8 | 1.2 × 103 |
| MGn-PA | MM-PA | 3.2 × 103 | 3.0 | 33.0 | 410 |
| GnM-PA | MM-PA | 6.4 × 103 | 1.0 | 22.0 | 620 |
| GnGnXF-PA | GnMXF-PA | 4.4 × 104 | 3.8 | 40.2 | 1.0 × 103 |
| GnGnXF-PA | MGnXF-PA | 1.6 × 103 | 0.8 | 7.0 | 700 |
| Man5Gn-PA | Man5-PA | 3.0 × 103 | 4.1 | 21.6 | 800 |
| (GlcNAc)3-PA | (GlcNAc)2-PA | 3.0 × 103 | 1.2 × 103 | 27.5 | 1.0 × 103 |
| (GlcNAc)2-PA | GlcNAc-PA | 1.0 × 103 | <2 | <1 | 400 |