Activity of Purified rHuEPO Variants
| Mutation . | Receptor Binding . | In Vitro Activity . | RIA-9G8A (U/mg) . | ||
|---|---|---|---|---|---|
| . | U/mg . | % of rHuEPO . | U/mg . | % of rHuEPO . | . |
| rHuEPO | 175,000 | 100 | 179,000 | 100 | 144,000 |
| Arg14/Gln | 32,000 | 18 | 6,100 | 3.4 | 193,000 |
| Trp51/Phe | 40,200 | 23 | 54,000 | 30 | 454,000 |
| Asn147/Lys | 1,600 | 0.92 | 980 | 0.55 | 500,000 |
| Mutation . | Receptor Binding . | In Vitro Activity . | RIA-9G8A (U/mg) . | ||
|---|---|---|---|---|---|
| . | U/mg . | % of rHuEPO . | U/mg . | % of rHuEPO . | . |
| rHuEPO | 175,000 | 100 | 179,000 | 100 | 144,000 |
| Arg14/Gln | 32,000 | 18 | 6,100 | 3.4 | 193,000 |
| Trp51/Phe | 40,200 | 23 | 54,000 | 30 | 454,000 |
| Asn147/Lys | 1,600 | 0.92 | 980 | 0.55 | 500,000 |
Activity was determined as described in Table 1 and the Materials and Methods. Specific activity was calculated from activity (U/mL) by dividing by the protein concentration (determined from absorbance at A280).