Imidazole-free purification of His3-tagged recombinant proteins using ssDNA aptamer-based affinity chromatography

Immobilized metal ion affinity chromatography (IMAC) is widely used for the purification of many different His(6)-tagged recombinant proteins. On the one hand, it is a powerful technique but on the other hand it has its disadvantages. In this report, we present the development of a unique ssDNA aptamer for the purification of His(3)-tagged recombinant proteins. Our study shows that stability of the His(3)-tag/H3T aptamer complex can be controlled by the sodium ion concentration. Based on this feature, we demonstrate that H3T aptamer resin was successfully employed for the purification of three out of four tested His(3)-tagged recombinant proteins from an E. coli total protein extract using imidazole-free buffers. Finally, we show that the purity of His(3)-tagged proteins is superior when purified with the help of the H3T aptamer in comparison with Ni-NTA resin. (C) 2015 Elsevier B.V. All rights reserved.