QuickTip #4: yield of His-tagged proteins

Immobilized Metal Ion Affinity Chromatography (IMAC) is used for purification of His-tagged proteins. Ni-NTA based resins are the most commonly used as the Ni2+ ion is considered to have the strongest affinity to histidine-tagged proteins but stringent requirements on the yield of target protein can make it well worth the extra effort of trying another metal ion to optimize the purification process...

Under some circumstances, other transition metal ions such as Co2+, Cu2+, Fe2+ and Zn2+ may prove to be more suitable. This is, of course, just one of the factors affecting binding of the His-tagged protein to the metal ion. There’s also the structure and characteristics of the protein and the pH and composition of the binding buffer etc.

When purifying His-tagged proteins expressed in yeast and mammalian cells screening of the optimized metal ion or ligand is suggested. Since these expression systems are more complex, the host cell impurities are more complex in comparison with His-tagged proteins expressed in bacterial host cells.

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The Bio-Works Team

Posted by The Bio-Works Team

The Bio-Works staff are seasoned and enthusiastic (yes, even a bit nerdy) experts in purification resins, methods and strategies with many years of experience of the ins and outs of this field. We love our job and we’d love to help you do yours by sharing some good solid facts, principles and best practice. In short – “purification made simple”.