Boronate-mediated antibody orientation: a molecular simulation-guided strategy for ultra-sensitive lateral flow
Zehao Yang1, Xiliang Yan2, Zijun Yang1
1Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.
The random immobilization of antibodies on lateral flow immunoassay (LFIA) strips remains a major factor limiting assay sensitivity and consistency. To address this, we report a boronate affinity-based strategy for site-specific antibody orientation via covalent reaction between boronic acid and cis-diol groups on Fc-region glycans. Molecular dynamics simulations provided mechanistic support for this design. The boronate-antibody configuration demonstrated the most favorable binding energy (- 153.93 kJ/mol) and the fastest conformational stabilization (< 40 ns), suggesting a stabilization process involving initial electrostatic guidance followed by hydrogen-bond and covalent bond formation. Experimentally, this oriented immobilization achieved an antibody conjugation efficiency of 99.92%, a Fab exposure rate of 47.52% and significantly improved functional activity, with an affinity constant of 0.93 × 10⁸ M⁻¹, outperforming conventional passive adsorption. Applied to the detection of zearalenone (ZEN) in corn, the oriented LFIA showed a dramatic sensitivity enhancement. The limit of detection reached 0.049 µg/kg, 200-fold higher than traditional colloidal gold LFIA. The visual cut-off value was 0.5 µg/kg. Validation with spiked and naturally contaminated samples yielded recoveries of 84.7%-103.4% (CV: 7.1%-12.6%) and excellent correlation (R2 > 0.97) with LC-MS/MS. This work establishes a rational, chemistry-driven paradigm for antibody immobilization that can be generalized to enhance the performance of next-generation rapid diagnostics.
The random immobilization of antibodies on lateral flow immunoassay (LFIA) strips remains a major factor limiting assay sensitivity and consistency. To address this, we report a boronate affinity-based strategy for site-specific antibody orientation via covalent reaction between boronic acid and cis-diol groups on Fc-region glycans. Molecular dynamics simulations provided mechanistic support for this design. The boronate-antibody configuration demonstrated the most favorable binding energy (- 153.93 kJ/mol) and the fastest conformational stabilization (< 40 ns), suggesting a stabilization process involving initial electrostatic guidance followed by hydrogen-bond and covalent bond formation. Experimentally, this oriented immobilization achieved an antibody conjugation efficiency of 99.92%, a Fab exposure rate of 47.52% and significantly improved functional activity, with an affinity constant of 0.93 × 10⁸ M⁻¹, outperforming conventional passive adsorption. Applied to the detection of zearalenone (ZEN) in corn, the oriented LFIA showed a dramatic sensitivity enhancement. The limit of detection reached 0.049 µg/kg, 200-fold higher than traditional colloidal gold LFIA. The visual cut-off value was 0.5 µg/kg. Validation with spiked and naturally contaminated samples yielded recoveries of 84.7%-103.4% (CV: 7.1%-12.6%) and excellent correlation (R2 > 0.97) with LC-MS/MS. This work establishes a rational, chemistry-driven paradigm for antibody immobilization that can be generalized to enhance the performance of next-generation rapid diagnostics.
