Table 2 of
Baer, Mol Vis 4:30, 1998.Table 2 of
Baer, Mol Vis 4:30, 1998.
Table 2. Summary of binding parameters determined by quenching titrations
The binding of 9-(9-anthroyloxy) stearic acid (9-AS) and all-trans retinol to X4IRBP and the Arg->Gln substitution mutants was followed by monitoring quenching of protein endogenous fluorescence. The number of ligand-binding sites (N) and the dissociation constant (Kd) were determined as described by Baer et al. [48].
Protein 9-AS Quenching* All-trans retinol Quenching*
------------ ------------------------ ----------------------------
N Kd N Kd
--------- ------------ --------- ------------
X4IRBP 0.24±0.10 0.46±0.08 µM 0.15±0.08 0.58±0.08 µM
Arg1005->Gln 1.06±0.18 0.10±0.06 µM 0.51±0.11 0.28±0.04 µM
Arg1041->Gln 0.32±0.13 0.38±0.09 µM 0.33±0.06 0.55±0.06 µM
Arg1073->Gln 0.39±0.16 0.36±0.09 µM 0.17±0.07 0.60±0.06 µM
Arg1122->Gln 0.12±0.07 0.35±0.05 µM 0.12±0.08 0.53±0.06 µM
* Monitored at 340 nm upon excitation at 280 nm.
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