TABLE 2.
Dissociation constants obtained by FP displacement experiments and microtubule tip versus cytoplasm ratios of +TIP-derived polypeptide sequences
| Kd ± S.D. (monomer) | Tip/cytoplasma (monomer) | Tip/cytoplasma (dimer)e | |
|---|---|---|---|
| μm | |||
| MACFp1 | 3.5 ± 0.01 | NDb | ND |
| MACFp1-NN | mmc | No tip tracking | ND |
| APCp1 | 7.5 ± 0.1 | ND | ND |
| TrxMACF | 1.6 ± 0.5 | 1.6 ± 0.4 | 7.0 ± 3 |
| TrxMelan | 1.5 ± 0.4 | 1.5 ± 0.3 | 3.0 ± 1 |
| TrxAPC | 3.3 ± 0.5 | ND | ND |
| TrxMCAK | 10 ± 0.5 | 1.3 ± 0.1 | 2.2 ± 0.7 |
| TrxCLASP2 | 13 ± 0.8 | ND | ND |
| TrxIpl1-p1 | 15 ± 1 | ND | ND |
| TrxDDA3 | 28 ± 1 | 1.4 ± 0.3 | 2.7 ± 0.8 |
| TrxIpl1-p2 | 89 ± 3 | ND | ND |
| TrxFILIP | 126 ± 4 | No tip tracking | 1.2 ± 0.2 |
| TrxSTIM1 | 140 ± 3 | ND | ND |
| TrxSLAIN2 | mm | ND | ND |
| TrxNAV1 | mm | ND | ND |
| TrxTip150 | mm | ND | ND |
| Trxp140Cap | mm | No tip tracking | No tip tracking |
| TrxCLIP-170 | mm | ND | ND |
| TrxIpl1-p12 | 0.15 ± 0.01 | ND | ND |
| TrxMACF-GCN4 | <1 nmd | ND | ND |
a The experiments were performed using N-terminal GFP instead of Trx fusions.
b ND, not determined.
c mm, data could not be subjected to rigorous analysis; however, the shape of the binding isotherms suggested that the Kd values are in the millimolar range or higher.
d Data could not be subjected to rigorous analysis; however, the shape of the binding isotherms suggested that the Kd is below 1 nm.
e Dimerization was achieved by fusing GCN4 to the C-terminus of the indicated constructs.