What does imidazole do in his tag?
What does imidazole do in his tag?
A his-tag, or polyhistidine tag, is a string of histidine residues at either the N or C terminus of a recombinant protein. Imidazole competes with the his-tag for binding to the metal-charged resin and thus is used for elution of the protein from an IMAC column.
What is a 6xHN tag?
Distinct types of his tags are available, including the 6xHN tag (12 amino acids) Most common affinity tag used to purify proteins. Binds to coordinated metals such as Ni2+ or Co2+ His-tagged proteins can be eluted with imidazole or low pH buffer. A his tag can be incorporated on either the N- or C-terminus.
How heavy is his tag?
His-tags. Molecular Weight: 0.2–1.6 kDa.
Why is affinity chromatography expensive?
Affinity chromatography is the most expensive chromatographic method, since often a highly purified protein (the antibody) must also be manufactured before the target protein.
What is Polyhistidine-tagging and how does it work?
Polyhistidine-tagging is the option of choice for purifying recombinant proteins in denaturing conditions because its mode of action is dependent only on the primary structure of proteins.
How many histidine residues are in a suitable tag sequence?
Suitable tag sequences are available free for commercial use; for example, MK (HQ)6 may be used for enhanced expression in E. coli and tag removal. The total number of histidine residues may vary in the tag from as low as two, to as high as 10 or more His residues.
What is hexa histidine-tag?
It is also known as hexa histidine-tag, 6xHis-tag, and by the trademarked name His-tag ® (registered by EMD Biosciences). The tag was invented by Roche and its vectors are distributed by Qiagen. A Variety of purification kits for histidine-tagged proteins are available from Qiagen, Sigma, Thermo Scientific, GE Healthcare and others.
How many histidines are in an iMac tag?
Typically, the tag is composed of 6–10 consecutive histidines at either terminus of the protein of interest, often separated by a protease-cleavage site. The presence of a His tag enables the use of IMAC for purification.
