TABLE 1.
Activities of the β-galactosidase purified from the E. coli transformant with various nitrophenol-derived chromagenic substrates
| Substratea | % Relative activityb |
|---|---|
| ONPG | 100 |
| PNPG | 92.96 |
| ONPF | 6.11 |
| PNPF | 3.77 |
| PNPL | <0.001 |
| PNPC | <0.001 |
| PNPαG | <0.001 |
| PNPX | <0.001 |
a
The substrate concentration used in each test was 5.0 mM. Abbreviations: ONPG, o-nitrophenyl-β-d-galactopyranoside; PNPG, p-nitrophenyl-β-d-galactopyranoside; ONPF, o-nitrophenyl-β-d-fucopyranoside; PNPF, p-nitrophenyl-β-d-fucopyranoside; PNPL, p-nitrophenyl-β-lactose; PNPC, p-nitrophenyl-β-cellobiose; PNPαG, p-nitrophenyl-α-galactopyranoside; PNPX, p-nitrophenyl-β-xylopyranoside.
b
The values are values relative to the activity observed with ONPG, which was 160 μmol of o-nitrophenol produced/min/mg of protein.