Figure 6. The binding of EcR2 to retinol: Titration of the protein-retinol interaction by varying the protein concentration

The K_d measured by increasing the retinol concentration at a constant protein concentration should be the same as the K_d found when varying the receptor (protein) concentration while holding the retinol concentration constant. The green triangles represent 1 µM solution of all-trans-retinol to which EcR2 was added. The blue circles represent the addition of EcR2 to buffer containing no retinol. Inspection of the plot suggests that the K_d measured by adding small increments of protein is the same as the K_d measured by incrementing the retinol concentration.