Ligand Binding and the Scatchard Plot

#kinetics

1.0

Equations

All Very important (2)

The Scatchard equation

Very important

\frac{\Theta}{[L]} = \frac{n}{K_d} - \frac{\Theta}{K_d}

$\Theta$ : fractional saturation, dimensionless
$[L]$ : free (unbound) ligand concentration, $\text{M}$
$n$ : total binding sites per protein molecule, dimensionless
$K_d$ : dissociation constant, $\text{M}$

The Scatchard equation

Very important

\frac{r}{[L]} = nK_a - rK_a = K_a(n - r)

$r$ : average ligand molecules bound per protein molecule, dimensionless
$[L]$ : free ligand concentration, $\text{M}$
$n$ : total binding sites per protein molecule, dimensionless
$K_a$ : association constant, $\text{M}^{-1}$

02 formulas