Anti-Histidine Antibodies as Tools for Reversible Capturing of His-Tagged Fusion Proteins for Subsequent Binding Analysis

The hexahistidine tag is one of most commonly used fusion tags in affinity purification of recombinantly expressed proteins. Real-time binding analysis using Biacore technology allows in-depth characterization of respective association and dissociation patterns of potential binders. Here we tested four commercially available anti-His antibodies for reversible capturing of His-tagged proteins as a basis for a subsequent interaction analysis with non-His-tagged proteins. Anti-penta-, anti-hexa- and anti-RGS-(His)4 antibodies from different distributors were covalently coupled to Biacore sensor chips. Parallel binding studies of 12 heterogeneously sized RGS-(His)6-tagged (Arg-Gly-Ser-(His)6) proteins revealed that the slowest dissociation rate was obtained when using an anti-RGS-(His)4 antibody. Thus in a sandwich binding assay the anti-RGS-(His)4 antibody can be utilized as an appropriate tool for stable yet reversible capturing of RGS-(His)6-tagged proteins with a non-His-tagged protein.