Table 4.
Substrate specificity of expandase when using cell-free extracts
| Substrate | Inhibition zone, mm |
|---|---|
| No substrate | 0 |
| Adipyl-6-APA | 20.0 |
| Ampicillin | 17.0 |
| Butyryl-6-APA | 17.5 |
| Decanoyl-6-APA | 7.0 |
| Heptanoyl-6-APA | 16.5 |
| Hexanoyl-6-APA | 19.5 |
| Nonanoyl-6-APA | 10.5 |
| Octanoyl-6-APA | 16.0 |
| Penicillin F | 21.0 |
| Penicillin G | 29.0 |
| Penicillin V | 7.5 |
| Penicillin mX | 30.5 |
| Penicillin X | 30.5 |
| 2-Thiophenylacetyl-6-APA | 32.0 |
| Valeryl-6-APA | 15.0 |
Reactions were carried by using 4 mg/ml enzyme protein, 1.8 mM FeSO4, 1.28 mM α-ketoglutarate, 8 mM KCl, 8 mM MgSO4, 4 mM ascorbic acid, and 14 mM DTT. 6-APA, 6-aminopenicillanic acid. All substrates were used at 2 mg/ml, except for penicillin mX and octanoyl-6-APA (3 mg/ml). Samples were taken at 2 h and were centrifuged (14,000 × g, 5 min). Bioassay was done by using 250 μl of reaction mixture.