Systematic evaluation of quantotypic peptides for targeted analysis of the human kinome

In targeted proteomics it is critical that peptides are not only proteotypic, but also accurately represent the level of the protein (quantotypic). Numerous approaches are used to identify proteotypic peptides, but quantotypic properties are rarely assessed. Here, we show that measuring ratios of proteotypic peptides across biological samples can be used to empirically identify peptides with good quantotypic properties, and use this to identify quantotypic peptides for 21% of the human kinome.

在靶向蛋白质组学（targeted proteomics）研究中，肽段不仅需具备蛋白特异性（proteotypic），还应能够精准反映对应蛋白质的表达水平，即具备定量特异性（quantotypic）。目前已有多种方法可用于鉴定蛋白特异性肽，但针对其定量特异性属性的评估却极为少见。本研究证实，通过测定蛋白特异性肽段在不同生物样本间的丰度比值，可通过实验手段筛选出具备优异定量特异性的肽段；基于此方法，我们成功为21%的人类激酶组（human kinome）鉴定出了对应的定量特异性肽段。