Comparison of mono-NTA and tris-NTA binding to His-tagged proteins. A, Mono-NTA is the traditional method for capturing His-tagged proteins but achieves weak binding and results in ligand drift, unstable baselines, distorted kinetic results, and inaccurate fitting to a kinetic model. B, ProteOn trivalent tris-NTA complexes improve binding stability and increase binding selectivity to His-tagged molecules. Ni-NTA (
) binding to histidine (
) occurs after activation with Ni2+.Hercules, CA – August 1, 2011– Bio-Rad Laboratories, Inc.'s ProteOn™ HTG Sensor Chip provides a robust new alternative for pharmaceutical researchers studying polyhystidine-tagged protein interactions that can reduce cost per data point by 90 percent.
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 reuse 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 and 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 reused 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.
Visit the following websites for more information on:
- ProteOn HTG Sensor Chip: http://bit.ly/BioRad_ProteOn_XPR36
- Webinar on how Pfizer-Rinat uses the ProteOn system to rapidly screen antibodies during drug discovery: http://bit.ly/ProteOn_Webinar_Series
About Bio-Rad
Bio-Rad Laboratories, Inc. (NYSE: BIO and BIOb) has remained at the center of scientific discovery for more than 50 years, manufacturing and distributing a broad range of products for the life science research and clinical diagnostic markets. The company is renowned worldwide among hospitals, universities, and major research institutions, as well as biotechnology and pharmaceutical companies, for its commitment to quality and customer service. Founded in 1952, Bio-Rad is headquartered in Hercules, California, and serves more than 100,000 research and industry customers worldwide through its global network of operations. The company employs more than 6,800 people globally and had revenues exceeding $1.9 billion in 2010. For more information, please visit http://www.biorad.com.
For more information contact:
Laura Moriarty
Bio-Rad Laboratories, Inc.
510-741-4017
Laura_Moriarty@bio-rad.com
Ken Li
Chempetitive Group
312-997-2436
kli@chempetitive.com