Table 2.
Purification of ADP-ribosylating protein from the hard clam M. lamarckii
| Step | Total protein, mg | Recovery of activity, % | Purification, fold |
|---|---|---|---|
| Extract | 3,175 | 100 | 1 |
| Ammonium sulfate fractionation | 439 | 80 | 6 |
| Carboxymethyl-cellulose chromatography | 14.5 | 43 | 96 |
| Sephacryl chromatography | 1.82 | 34 | 592 |
| Mono-S chromatography | 0.48 | 11 | 870 |
Recovery and purification values were calculated from the results of an assay measuring incorporation of radioactivity from 32P-NAD into DNA; all assays were performed in duplicate. The purification was repeated six times, and these experiments gave almost the same results. A typical example is shown.