The term Co-NTA refers to a copper Ion that has been coupled Nitrilotriacetic acid. Co-NTA can then be coupled to agarose or magnetic beads for IMAC (Immobilized Metal Chelate Affinity Chromatography). This is a purification method to obtain functional his tagged protein. Cube Biotech offers multiple different Co-NTA based products for protein purification.
Overview of Cube Biotech's Co-NTA products for his tag protein purification.
|Usage ||Specific binding and purification of 6x his-tagged proteins |
|Specifity ||Affinity to His-tagged proteins |
|Binding capacity ||>30 mg/mL |
|Chelator stability ||Stable in buffer containing 10 mM DTT and 1 mM EDTA |
|Bead Ligand ||Co-NTA |
Co-NTA Agarose from Cube Biotech was successfully used in the following publications:
|eGFP ||2015 ||Li Y., Lui Y., Gao T., Zhang B., Song Y., Terrell J-L., Barber N., Bentley W-E., Takeuchi I., Payne G-F., Wang Q.1 ||Co-NTA agarose (40 µm) |
|flavin-dependent tryptophan 6-halogenase Thal ||2018 || Moritzer A.-C., Minges H., Prior T., Frese M., Seewald N., Niemann H.H.2 ||Co-NTA agarose (40 µm) |
|HrpII ||2017 || Bauer W.S., Richardson K.A., Adams N.M., Ricks K.M., Gasperino D.J., Ghionea S.J., Rosen M., Nichols K.P., Weigl B.H., Haselton F.R., Wright D.W., 3 ||Co-NTA agarose (40 µm) |
|Metal Binding Phages ||2019 || Matys S., Schönberger N., Lederer F., Pollmann K.4 ||Co-NTA agarose (40 µm) |
Different metal ions confer different binding affinity and specificity
Fig. 1: Affinity and specificity of metal ions commonly used for IMAC. Loading an IMAC resin with different metal ions can adjust the affinity and specificity to optimize the purity and yield of a purified protein.
Loading different metal ions to a resin results in differing affinity and specificity for a his-tagged protein. Generally, cobalt exhibits the higest binding specificity of commonly used IMAC metal ions, leading to relatively low yields but high purity. Copper, at the other end of the spectrum, has a high affinity leading to high yields but unspecific binding. In searching for the optimal resin to purify a protein, it is recommended to explore different chelating ligands (IDA or NTA) and different metal ions.
1. Li, Y. et al. Self-assembly with orthogonal imposed stimuli to impart structure and confer magnetic function to electrodeposited hydrogel. Applied Materials & Interfaces, Published April 29, 2015
2. Moritzer, Ann-Christin et al. (2018). Structure-based switch of regioselectivity in the flavin-dependent tryptophan 6-halogenase Thal. Journal of Biological Chemistry. 294. jbc.RA118.005393. 10.1074/jbc.RA118.005393.
3. Bauer, Westley S et al. “Rapid concentration and elution of malarial antigen histidine-rich protein II using solid phase Zn(II) resin in a simple flow-through pipette tip format.” Biomicrofluidics vol. 11,3 034115. 2 Jun. 2017, doi:10.1063/1.4984788
4. Matys, S. et al. (2019). Characterization of specifically metal-binding phage clones for selective recovery of cobalt and nickel. Journal of Environmental Chemical Engineering. 103606. 10.1016/j.jece.2019.103606.