Highly-efficient purification of native polyhistidine-tagged proteins by multivalent NTA-modified magnetic nanoparticles.

ABSTRACT: A new bis-nitrilotriacetic acid (NTA) chelate with catechol anchor was synthesized and immobilized on superparamagnetic iron oxide nanoparticles. When loaded with Ni(II), these bis-NTA-immobilized nanoparticles were shown to bind polyhistidine (His x 6-tagged) fusion proteins in their native, folded conformations that commercial microbeads failed to bind under identical conditions. Control experiments with a mono-NTA chelate immobilized on iron oxide nanoparticles indicate a similarly high affinity for His x 6-tagged native proteins, suggesting that the high density of the mono-NTA chelate presented by the nanoparticles allows the binding of the His x 6-tag to more than one Ni-NTA moiety on the surface. This study shows that the multivalency strategy can be utilized to enhance the binding

SUBMITTER: Kim JS 

PROVIDER: S-EPMC2529454 | biostudies-literature | 2007 Mar-Apr

REPOSITORIES: biostudies-literature