Bio-Rad’s New HTG Sensor Chip Enables More Reliable Polyhistidine-Tagged Protein Interaction Studies by Surface Plasmon Resonance
Product News Aug 03, 2011
Used with Bio-Rad’s ProteOn XPR36 system, the HTG Sensor Chip’s innovative surface chemistry has increased binding stability and specificity for His-tagged proteins compared to chips from other surface plasmon resonance (SPR) system providers. Additionally, the HTG Sensor Chip’s ability to regenerate and re-use HTG chips multiple times can significantly reduce the cost of generating data.
“We’re excited to see that Bio-Rad has developed a His-capture chip that’s better than what’s now available,” said Dr. David Myszka, Director of the Center for Biomolecular Interaction Analysis at the University of Utah and founder of Biosensor Tools, a contract services and training provider on SPR-based biosensors. “Given the popularity of polyhistidine tags, these chips will open up additional applications of the ProteOn technology.”
Polyhistidine tags are the most common tags used in protein interaction analysis because they are small and rarely interfere with the function, activity, or structure of target proteins. According to a 2010 market research survey conducted by consultancy firm HTStec, polyhistidine protein tags were the second most used capture agent for immobilization after biotin. The problem is that the standard method for capturing His-tagged proteins on SPR sensor chips, the mono-NTA complex, achieves relatively weak binding. This results in signal drift and inaccurate kinetic results.
A Better Method for Polyhistidine Tag Binding
The ProteOn HTG Sensor Chip’s Tris-NTA complex contains three NTA molecules for improved binding stability and selectivity to His-tagged molecules. This results in better data quality and reduced ligand decay. Furthermore, binding via polyhistidine tag is reversible, so the ligand can be removed from the surface and the chip can be re-used ten times or more. This increases reproducibility by eliminating chip-to-chip variability, and it decreases cost per data point.
To optimize the polyhistidine-tagged protein interaction workflow, Bio-Rad has also introduced the ProteOn HTG Reagent kit for use with the ProteOn HTG Sensor Chip. The kit includes NiSO4 for chip activation and an EDTA solution for chip regeneration