Ma Rongna, Hu Junjie, Cai Zongwei, Ju Huangxian
State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Kowloon, Hong Kong, PR China.
Talanta. 2014 Feb;119:452-7. doi: 10.1016/j.talanta.2013.11.049. Epub 2013 Nov 22.
High-index facets exposed octahedral tin dioxide (SnO2) nanoparticles were successfully synthesized and applied to selectively enrich phosphopeptides for mass spectrometric analysis. The high selectivity and capacity of the octahedral SnO2 nanoparticles were demonstrated by effectively enriching phosphopeptides from digests of phosphoprotein (α- or β-casein), protein mixtures of β-casein and bovine serum albumin, milk, and human serum samples. The unique octahedral SnO2 with abundant unsaturated coordination Sn atoms exhibited enhanced affinity and selective coordination ability with phosphopeptides due to their high chemical activity. The strong affinity led to highly selective capture and enrichment of phosphopeptides for sensitive detection through the bidentate bonds formed between surface atoms and phosphate. The phosphopeptides could be detected in β-casein down to 4 × 10(-9)M or in the mixture of β-casein and BSA with a molar ratio of even 1:100. The performance in selective enrichment of phosphopeptides from drinking milk and human serum showed powerful evidence of high selectivity and efficiency in identifying the low-abundant phosphopeptides from complicated biological samples. This work provided a way to improve the physical and chemical properties of materials by tailoring their exposed facets for selective enrichment of phosphopeptides.
成功合成了具有高指数晶面的八面体二氧化锡（SnO2）纳米颗粒，并将其应用于选择性富集磷酸化肽段以进行质谱分析。通过从磷蛋白（α-或β-酪蛋白）消化物、β-酪蛋白与牛血清白蛋白的蛋白质混合物、牛奶和人血清样品中有效富集磷酸化肽段，证明了八面体SnO2纳米颗粒具有高选择性和高容量。独特的八面体SnO2具有丰富的不饱和配位Sn原子，由于其高化学活性，对磷酸化肽段表现出增强的亲和力和选择性配位能力。这种强亲和力导致通过表面原子与磷酸之间形成的双齿键对磷酸化肽段进行高度选择性的捕获和富集，从而实现灵敏检测。在β-酪蛋白中可检测到低至4×10^(-9)M的磷酸化肽段，在β-酪蛋白与牛血清白蛋白摩尔比为1:100的混合物中也能检测到。从牛奶和人血清中选择性富集磷酸化肽段的性能有力地证明了在从复杂生物样品中鉴定低丰度磷酸化肽段方面具有高选择性和高效率。这项工作提供了一种通过调整材料的暴露晶面来改善其物理和化学性质以选择性富集磷酸化肽段的方法。
