Method and apparatus for rapid determination of ligand-protein binding using charcoal adsorption

A method for evaluating binding of a ligand to a target protein, the method comprising:

• (a) providing a sample comprising a target protein and a first ligand, wherein the first ligand comprises a detectable label, and wherein the target protein and first ligand are suspected to be bound reversibly together in a complex;
• (b) contacting the sample with a candidate second ligand for a time sufficient for displacement of the first ligand from the complex by the second ligand;
• (c) preconditioning activated charcoal with the target protein;
• (d) contacting the sample of (b) with the pre-conditioned activated charcoal for a time sufficient to allow for adsorption of unbound first ligand to the activated charcoal;
• (e) eluting the sample from the activated charcoal;
• and
• (f) determining an amount of first ligand in the eluted sample to thereby evaluate binding of the second ligand to the target protein.

A method for evaluating the susceptibility of a candidate drug to binding a protein found in the circulating blood of a warm-blooded vertebrate, the method comprising:

• (a) providing a sample comprising a target protein and a ligand, wherein the ligand comprises a detectable label, and wherein the target protein and ligand are suspected to be bound reversibly together in a complex;
• (b) contacting the sample with a candidate drug for a time sufficient for displacement of the ligand from the complex by the candidate drug;
• (c) preconditioning activated charcoal with the target protein;
• (d) contacting the sample of (b) with the pre-conditioned activated charcoal for a time sufficient to allow for adsorption of unbound ligand to the activated charcoal;
• (e) eluting the sample from the activated charcoal;
• and
• (f) determining an amount of ligand in the eluted sample to thereby evaluate the susceptibility of the candidate drug to binding a protein found in the circulating blood of a warm-blooded vertebrate.

A method for preparing a packed-bed activated charcoal cartridge unit, the method comprising:

• (a) providing a column comprising a sample chamber, a sample addition port, a sample elution port adapted for fluid/gaseous communication with a suction source, and a barrier positioned between the sample chamber and the sample elution port;
• (b) applying activated charcoal in a liquid suspension to the column;
• and
• (c) eluting the liquid from the column, whereby the activated charcoal is packed adjacent to the barrier, and whereby a packed-bed activated charcoal cartridge is prepared.