: Fluorescence and dissociation of wild-type versus mYFPs without lipid modifications. Dissociation constantK d (mM) derived from the association constant (K a) was measured by sedimentation equilibrium analytical ultracentrifugation. Variance (goodness of fit) was determined by global analysis with a nonlinear least-squares algorithm in the software provided by Beckman. Each value is statistically significant.
| Mutation | Quantum yield | Extinction coefficient (M−1cm−1) | Kd | Variance |
|---|---|---|---|---|
| Wild type | 0.67 | 67,000 | 0.11 | 1.25E-3 |
| L221K | 0.67 | 64,000 | 9.7 | 1.35E-3 |
| F223R | 0.53 | 65,000 | 4.8 | 1.48E-3 |
| L221K/F223R | 0.68 | 59,000 | 2.4 | 4.60E-4 |
| A206K | 0.62 | 79,000 | 74* | 6.65E-4* |
↵* Due to the extreme monomeric nature of this protein it was difficult to determine an accurate dissociation constant for a hypothetical dimer.