Immobilized Metal Ion Affinity Chromatography (IMAC), developed by Porath (1), is based on the interaction of certain protein residues (histidines, cysteines, and to some extent tryptophans) with cations of transition metals.
The Cobalt Chelating Resin is specifically designed for the purification of proteins that associate with Cobalt ions, including 6x histidine tagged proteins. Although 6 X His tagged proteins bind with a slightly lower efficiency compared to Nickel Chelating Resin
there is a significant reduction in non-specific binding. Cobalt resins have a higher selectivity for poly-His sequences, however have a low loading capacity, therefore Cobalt Chelating Resin should be used for valuable recombinant proteins in limited quantities.
Immobilized metal affinity chromatography (IMAC) resin utilizing cobalt (Co2+) for the purification of 6x histidine tagged proteins.
This resin binds to six histidine residues (6x His), a common tag used in protein purification. The resin consists of iminodiacetate coupled to 6% cross-linked agarose beads. The iminodiacetate binds divalent cobalt ion with a capacity of 20-40μmoles Co2+/ml resin. The protein binding capacity is >50mg protein per ml resin. We have demonstrated binding of >100mg of a 50kDa 6XHis tagged proteins to a ml of resin.
The spin columns are supplied with a resin bed volume of 0.2, 1 and 3ml with total column volumes of 1, 8 and 22ml respectively. Columns can be used as a spin format of gravity flow columns.
Chelating Resins are also available. Cobalt has the highest selectivity followed by Zinc, Nickel then Copper, but has the lowest loading capacity. Copper has the highest loading capacity, followed by Nickel then Zinc.
Our new HOOK™ 6X His Protein Purification kits are now available and include everything required for purification of 6X His tagged proteins from yeast or bacteria, including lysis buffers, lytic enzymes, resin, columns and binding, wash and elution buffers. Each kit is available with nickel or cobalt chelating resins. Kits available are:
- For the purification of Cobalt Binding proteins, including 6x His proteins
- High capacity: >50mg/ml
- Ligand density: 20-40μmoles Co2+ /ml resin
- Bead Structure: 6% cross-linked agarose
- Affinity purification of cobalt binding proteins
- Affinity purification of proteins with a 6x His tag.