Sulfate-binding protein dislikes protonated oxyacids. A molecular explanation.

  title={Sulfate-binding protein dislikes protonated oxyacids. A molecular explanation.},
  author={Bruce L. Jacobson and Florante A. Quiocho},
  journal={Journal of molecular biology},
  volume={204 3},
We have determined the effect of pH on the binding affinities of the conjugate bases of four different tetrahedral oxyacids to the sulfate-binding protein. The equilibrium dissociation constants of the binding of sulfate (Kd = 0.12 microM) and selenate (Kd = 5 microM) were found to be pH independent over the range pH 5 to pH 8.1, whereas chromate binding exhibited a pH dependence that is approximately attributable to the pK2 of the chromic acid. Phosphate was bound with an affinity five orders… CONTINUE READING