Bead-based ligand fishing

BALTIMORE—In screening for binding partners for proteins, SPR and bioaffinity chromatography have traditionally been the methods of choice, but the systems can be compromised by debris found in cellular or botanical extracts. Researchers at the National Institutes in Aging and PSS Bio Instruments recently circumvented this fouling problem, however, by adapting bioaffinity techniques to magnetic beads.

In a proof-of-concept study published in Analytical Chemistry, the researchers conjugated human serum albumin (HSA) to Bioclone magnetic beads to see if they could reproducibly separate known HSA-binders from known non-binders. They combined the HSA beads with a mixture of six compounds, and then isolated and washed the beads using a Dynal magnetic separator.

Using this manual system, the researchers found they could effectively separate the compounds into binding and nonbinding groups. They then repeated the experiment using the automated Magtration System 12GC, and found that the automated system was equally effective. Given these results, the researchers report they will next use the systems to identify protein-protein and protein-ligand interactions from cellular or botanical extracts.