TABLE 2.
Purification of the antimicrobial peptide
| Purification step | Volume (ml) | A280 | Antimicrobial activity (AU/ml) | Specific activity (AU/ml/A280) | Fold increase in specific activity |
|---|---|---|---|---|---|
| Culture supernatant | 500 | 0.19 | 160a | 8.5 × 102 | 1 |
| Ammonium sulfate precipitate | 10 | 9.40 | 5,120a | 5.5 × 102 | 0.6 |
| Cation-exchange chromatography | 20 | 0.21 | 5,120 | 2.5 × 104 | 29 |
| Reverse-phase chromatography | 2 | 0.05 | 12,800 | 2.6 × 105 | 303 |
| Reverse-phase chromatography (C8) | 0.5 | 0.03 | 25,600 | 8.5 × 105 | 1,013 |
a
Antimicrobial activity measured after treatment with proteinase K.