Rapid and regenerable surface plasmon resonance determinations of biomarker concentration and biomolecular interaction based on tris-nitrilotriacetic acid chips

• Published in: Analytica chimica acta Vol. 1170; p. 338625
• Main Authors: Liu, Luyao, Han, Chaowei, Jiang, Meng, Zhang, Tiantian, Kang, Qing, Wang, Xiaoying, Wang, Pengcheng, Zhou, Feimeng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.07.2021
• Subjects: Antibody–antigen interaction; Concentration determination; His-tagged protein; Surface plasmon resonance; Tris-NTA chip; Surface plasmon resonance; Antibody–antigen interaction; Concentration determination; Tris-NTA chip; His-tagged protein
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2021.338625

The tris-nitrilotriacetic acid (tris-NTA) chip has been used for surface plasmon resonance (SPR) kinetic studies involving histidine (His)-tagged proteins. However, its full potential, especially for analyte quantification in complex biological media, has not been realized due to a lack of systematic studies on the factors governing ligand immobilization, surface regeneration, and data analysis. We demonstrate that the tris-NTA chip not only retains His-tagged proteins more strongly than its mono-NTA counterpart, but also orients them more uniformly than protein molecules coupled to carboxymethylated dextran films. We accurately and rapidly quantified immunoglobulin (IgG) molecules in sera by using the initial association phase of their conjugation with His-tagged protein G densely immobilized onto the tris-NTA chip, and established criteria for selecting the optimal time for constructing the calibration curve. The method is highly reproducible (less than 2% RSD) and three orders of magnitude more sensitive than immunoturbidimetry. In addition, we found that the amount of His-protein immobilized is highly dependent on the protein isoelectric point (pI). Reliable kinetic data in a multi-channel SPR instrument can also be rapidly obtained by using a low density of immobilized His-tagged protein. The experimental parameters and procedures outlined in this study help expand the range of SPR applications involving His-tagged proteins. [Display omitted] •Tris-nitrilotriacetic acid sensor greatly enhanced biomarker detections.•High-throughput and accurate kinetic measurements with a multi-channel SPR.•Sensitive, rapid, and regenerable serological assays of biomarkers.•Delineation of factors governing accurate concentration and kinetic analyses.