What is BMAX Scatchard plot?
Bmax is the X intercept; Kd is the negative reciprocal of the slope. When making a Scatchard plot, you have to choose units for the Y axis. The negative reciprocal of the slope is expressed in units of concentration (nM) which equals the Kd.
How Scatchard equation is derived?
the Scatchard equation relates these by: r [ L ] = n K a − r K a . Scatchard plots of r vs r/[L], where r = [PLn]/[P]. Plot a is for multiple independent sites; the slope is the negative of the binding (affinity) constant Ka and from the y-intercept the number of binding sites (n) can be determined.
What does high BMAX mean?
More simply, the strength of the ligand–receptor interaction. At saturation, Bmax is determined (maximum receptor number) and half of this is used to determine KD (Fig. 1). High affinity binding occurs at low drug concentrations; conversely, low affinity binding occurs at high drug concentration.
What is the difference between KD and EC50?
The EC50 indicates how much of a drug is needed to achieve 50% of the maximum response. The more potent a drug, the smaller the EC50 will be. This value is obtained from a dose-response curve. Kd is the dissociation constant and can only be obtained from a binding curve/fractional occupancy curve).
What is the difference between KA and KD?
Kd is the inverse of the equilibrium association constant, Ka, (i.e Kd = 1/Ka). Ka is defined as [AB]/[A][B} so it *is* higher with higher affinity. But, it’s in inconvenient units (M⁻¹) so biochemists usually work with Kd which is in nicer units (M or mM or nM or μM or whatever).
Which is an example of a Scatchard plot?
For example, in a Scatchard plot a straight line would suggest a same/single binding affinity between antigen and antibody, as found in most immunoassays. The slope and intercept could be used to deduce the affinity constant ( Ka) and the number of binding sites ( n) per antibody molecule, respectively, in serum samples free from interference.
Which is better Scatchard plot or Eadie-hoffstee plot?
The Scatchard plot is better than the Eadie–Hoffstee plot for binding data because it depends more on the values at high ligand concentration, the most reliable values. Nonlinearity can arise through heterogeneity of receptors, although there are other possible causes.
What does a Scatchard plot of 125 I-VIP indicate?
A Scatchard plot of 125 I-VIP binding at steady state is curvilinear with an upward concavity. This does not indicate negative cooperativity since there is no acceleration of dissociation of bound 125 I-VIP by unlabeled VIP [ 61 ].
What is the Kd value of a Scatchard plot?
The Kd value estimated from Scatchard plots is about 0.6 nM in the membranes of follicle cells. However, the GSS receptor has not yet been identified.