Notes on tag-free recombinant protein purification

Bio-Rad Laboratories has a new technical note (tech note 5656A), which describes the purification of tag-free recombinant proteins using the Profinity Exact fusion-tag system

Affinity tagging has become a popular strategy for purifying recombinant proteins or functional domains in the postgenomic era.

However, for some structural studies and therapeutic or diagnostic applications, it is desirable to produce a native or tag-free protein that avoids potential interference from the affinity tag.

In this technical note, Bio-Rad demonstrates how a number of tag-free recombinant proteins of varying molecular weights (6-116kD) can be purified using the Profinity Exact fusion-tag system and its performance tested using various parameters.

The data demonstrates the benefits of this affinity purification and tag removal system, including the selective capturing of tagged proteins, the precise on-column proteolytic cleavage and binding of the affinity tag to the column, and the overall efficiency and simplicity of the purification protocol.

The technical note also demonstrates how preparation of a tag-free protein, without any additional N-terminal residues, is typically accomplished in about an hour in contrast to other affinity-tag purification and tag-removal systems that usually require substantial condition optimisation and lengthy, overnight protocols.

Availability Technical note 5656A is available from either a local Bio-Rad sales office or it may be downloaded from the Bio-Rad website.

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