Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
Institute of Advanced Study, University of Warwick, Coventry, CV4 7AL, UK.
Nanoscale Horiz. 2023 Feb 27;8(3):377-382. doi: 10.1039/d2nh00470d.
Glycoforms (and other post-translational modifications) of otherwise identical proteins can indicate pathogenesis/disease state and hence new tools to detect and sense a protein's glycosylation status are essential. Antibody-based assays against specific protein sequences do not typically discriminate between glycoforms. Here we demonstrate a 'sandwich' bio-assay approach, whereby antibodies immobilised onto biolayer interferometry sensors first select proteins, and then the specific glycoform is identified using gold nanoparticles functionalised with lectins which provide signal enhancement. The nanoparticles significantly enhance the signal relative to lectins alone, allowing glycoform specific detection as low as 0.04 μg mL (1.4 nM) in buffer, and crucially there is no need for an enrichment step and all steps can be automated. Proof of concept is demonstrated using prostate specific antigen: a biomarker for prostate cancer, where glycoform analysis could distinguish between cancerous and non-cancerous status, rather than only detecting overall protein concentration.
糖型（和其他翻译后修饰）的蛋白质即使在其他方面相同，也可以指示发病机制/疾病状态，因此，检测和感知蛋白质糖基化状态的新工具是必不可少的。针对特定蛋白质序列的抗体检测通常无法区分糖型。在这里，我们展示了一种“三明治”生物测定方法，该方法中，固定在生物层干涉传感器上的抗体首先选择蛋白质，然后使用带有凝集素的金纳米粒子来识别特定的糖型，该凝集素可提供信号增强。与单独的凝集素相比，纳米粒子显著增强了信号，使得糖型特异性检测在缓冲液中低至 0.04 μg mL（1.4 nM），至关重要的是，不需要富集步骤，并且所有步骤都可以自动化。使用前列腺特异性抗原（前列腺癌的生物标志物）进行了概念验证，其中糖型分析可以区分癌症和非癌症状态，而不仅仅是检测总蛋白浓度。
