In drug discovery research, it is extremely important to separate and identify proteins that are targets of drugs (compounds) in vivo and analyze their functions. However, in the past, it has been a problem that it takes a lot of labor and time to separate and identify the proteins that is the target of the drug. The nano-magnetic beads “FG beads” were developed to overcome this problem.
FG beads are magnetic beads with a diameter of about 0.2 μm, in which multiple magnetic materials (ferrites) are coated with a special polymer called polyGMA (glycidyl methacrylate). FG beads developed by this unique technology is a carrier for affinity purification with excellent characteristics not found in conventional carriers, and enables one-step affinity purification.
Affinity purification of the target proteins using FG beads consists of binding, washing, and elution. FG beads and the solution are separated using a magnet.
FG beads with an immobilized ligand are added to the cell extract to bind proteins that have an affinity for the ligand.
Wash away proteins that are non-specifically adsorbed to the ligand.
The proteins specifically bound to the ligand is eluted from the ligand and recovered.
Due to the nature of the polyGMA that coats the surface, non-specific adsorption of the protein is extremely low, and the target proteins can be purified with high purity. In addition, the target proteins can be recovered without the influence of large proteins and denatured proteins that are recovered by centrifugation.
Since FG beads are nano-sized, they have a large surface area with respect to volume and are highly dispersible, so target proteins can be efficiently bound.
Due to its resistance to various organic solvents※, FG beads do not denature or degrade in organic solvents and can immobilize various ligands.
※Methanol, DMF, DMSO, THF, ethyl acetate, pyridine, dioxane, toluene, dichloromethane, chloroform, etc.
The anticancer drug methotrexate (MTX) was immobilized on the magnetic beads of each company by the same method, and affinity purification was performed. Compared to magnetic beads of other companies, FG beads have less non-specific adsorption of proteins, and DHFR, which is the target protein of MTX, could be purified with high purity. Please refer to the document for details.
If the molecular weight of the target proteins is larger than that of the ligand, or if there is a binding site for the ligand inside the target proteins, steric hindrance may significantly reduce the efficiency of affinity purification.
A chain of molecules called a linker is introduced on the surface of FG beads. (Excluding Plain beads) You can avoid this problem by immobilizing the ligand on the FG beads via the linker.