TABLE 2.
Binding characteristics of profilin IIa and profilin IIb for actin (GP5)3 and PIP2
| Profilin | Kd for actin (μM) | (GP5)3Rmax/2a at μM | PIP2 bindingc |
|---|---|---|---|
| Human profilin I | 0.4 | NVb | ++++ |
| Human profilin IIb | 0.6 | NV | + |
| Rat profilin IIa | 1.0 | 0.3 | ++ |
| Bovine profilin IIa | 0.7 | 0.5 | ++ |
a
The interaction with peptide (GP5)3 was measured assuming a stoichiometry of two profilin molecules for one peptide (21).
b
NV, no value; Rmax/2 was not reached at the highest concentration used, 200 and 127 μM for profilin I and profilin IIb, respectively.
c
+ to ++++, lowest to highest level of binding, respectively.