Affinity Capture of a Mammalian DNA Polymerase β by Inhibitors Immobilized to Resins Used in Solid-Phase Organic Synthesis

The application of resins normally used in solid-phase organic synthesis to the affinity capture of a mammalian DNA polymerase β (pol β) is reported. Lithocholic acid (LCA), an inhibitor of pol β, was immobilized on various solid supports, and the batch affinity purification of pol β from a mixture of proteins using these LCA-immobilized resins was examined. Of the resins tested, TentaGel was the most effective at purifying pol β and at resisting nonspecific absorption of proteins. The immobilized LCA recognized pol β specifically, which resulted in pol β binding to the resin. Using the LCA-immobilized resin, it was possible to purify pol β from a mixture of proteins. Furthermore, it was possible to concentrate pol β from a crude nuclear extract of human T lymphoma Molt4 cells. To facilitate the immobilization of compounds on TentaGel resins, we also designed and prepared photoaffinity beads containing a photoreactive group at the free termini of the TentaGel resin. The pol β inhibitors LCA, C18-β-SQDG, a...