Increased adsorption of histidine-tagged proteins onto tissue culture polystyrene.
In this study we compare histidine-tagged and native proteins with regards to adsorption properties. We observe significantly increased adsorption of proteins with an incorporated polyhistidine amino acid motif (HIS-tag) onto tissue culture polystyrene (TCPS) compared to similar proteins without a HIS-tag. The effect is not observed on polystyrene (PS). Adsorption experiments have been performed at physiological pH (7.4) and the effect was only observed for the investigated proteins that have pI values below or around 7.4. Competitive adsorption experiments with imidazole and ethylenediaminetetraacetic acid (EDTA), as well as adsorption performed at different pH and ionic strength indicates that the high adsorption is caused by electrostatic interaction between negatively charged carboxylate groups on the TCPS surface and positively charged histidine residues in the proteins. Pre-adsorption of bovine serum albumin (BSA) does not decrease the adsorption of HIS-tagged proteins onto TCPS. Our findings identify a potential problem in using HIS-tagged signalling molecule in assays with cells cultured on TCPS, since the concentration of the molecule in solution might be affected and this could critically influence the assay outcome.
Department of Micro- and Nanotechnology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
Maria
M
Holmberg
Thomas Steen
TS
Hansen
Johan Ulrik
JU
Lind
Gertrud Malene
GM
Hjortø
D000327:Adsorption; D000818:Animals; D006639:Histidine / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011137:Polystyrenes / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D046509:Tissue Culture Techniques
D011137:Polystyrenes; D011993:Recombinant Fusion Proteins; D006639:Histidine