Table 2. Antagonistic activity of human (h) and ovine (o) leptin muteins in BAF/3 cells stably transfected with the long form of hLEPR.
Cells were stimulated with 62.5 pM leptin. IC50 values are means±S.E.M. (or means±S.D. where indicated by an asterisk, *) for the number of experiments indicated in parentheses.
| IC50 (nM) | |||
|---|---|---|---|
| Mutein | h-leptin | o-leptin | Agonistic activity |
| L39A/D40A | 17.7±3.76 (4) | 41.8±14.1 (7) | None |
| F41A | 531±447* (2) | Not prepared | Very weak |
| I42A | 53.4±16.5 (4) | Not prepared | Very weak |
| F41A/I42A | 15.6±3.87 (4) | 31.0±19.9 (3) | None |
| L39A/D40A/F41A | 11.9±1.94 (3) | 18.0±6.2 (3) | None |
| L39A/D40A/F41A/I42A | 9.3±1.60 (5) | 9.5±4.6 (3) | None |
| Y119A | Not prepared | No inhibition | Weak (5%) |
| L39A/D40A/Y119A | Not prepared | 98.0±14.6 (3) | Very weak |
| S120A/T121A† | 165±81 (5) | Not prepared | Very weak |
| L39A/D40A/F41A/I42A/S120A/T121A | 14.3±1.34* (2) | Not prepared | None |
† Mutein prepared as described in [12].