Question

Affinity chromatography is a method that can be used to purify cell-surface receptors, while they retain their hormone-binding ability. A ligand (hormone) for a receptor of interest is chemically linked to polystyrene beads. A solubilized preparation of membrane proteins is passed over a column containing these beads. Only the receptor binds to the beads. This method of affinity chromatography would be expected to collect which of the following? A. Molecules of the hormone. B. Molecules of purified receptor. C. G protein. D. Assorted membrane proteins. E. Hormone-receptor complexes.

Answer 1

Affinity chromatography is a method used to separate molecules with high affinity. This technique enables the purification of specific molecules ranging form nucleic acids, enzymes, antigens, antibodies, etc. In the example, the ligand will produce the receptor to be displaced from the beads and then eluted out.

Answer 2

Answer:

B: Molecules of purified receptor

Explanation:

Affinity chromatography is used mostly for biological systems because of high natural specificity between different biomolecules. Various applications include the use of enzymes, coenzymes, hormones, nucleotides, sugars etc to isolate viruses, cells and macromolecules. It has been widely applied to the purification of monoclonal antibodies, receptor proteins and recombinant proteins  

Affinity chromatography is used to perform high levels of purification based on interaction between proteins and ligands. The ligand is attached to the solid matrix (chromatograph) by covalent bond, then a mixture of molecules is passed through the column. Only the molecules that show a higher affinity for the ligand would remain in the column while other materials that lacks specificity for the ligand would pass through the column. The molecules are further purified and reversibly adsorbed by an immobilised ligand. Successful binding interactions between the ligand and the protein must be reversible to avoid disruption of the biological properties during elution from the column.