精氨酸二甲基化（MetR）是蛋白质的重要翻译后修饰，可调控信号转导、细胞凋亡等关键生理过程。然而，传统蛋白质组学方法利用数据依赖型方式采集二极谱数据，对低丰度MetR肽段造成大量漏检和误检。为提高检测的灵敏度和可信度，本项目拟开发新颖的co-Neutron-Encoding （coNeuCode）技术，并结合靶向串联质谱方法对蛋白质MetR进行大规模质谱表征。①标签研发：研发稳定同位素标记的coNeuCode氨基酸，实现细胞培养中MetR的位点专一性标记；②流程开发：开发用于 “特征谱”定位的计算机程序NeuCodeFinder，并优化分离、富集等关键技术节点，建立并评估质谱定性定量分析流程。③生物应用：应用coNeuCode技术对癌细胞中精氨酸甲基化转移酶的底物进行筛选鉴定，并绘制位点地图和调控网络。④试剂盒：构建具有自主知识产权的试剂盒。

The arginine dimethylation is an important post-translational modification, which plays a role in regulation of the cellular processes, including signal transduction, apoptosis, etc. However, the analysis of dimethylarginine (MetR) in proteins by traditional proteomic approaches relies on data-dependent acquisition for tandem mass spectrometry (MS/MS), resulting in a large number of misidentifications. Herein, we propose to develop a novel co-neutron-encoding (coNeuCode) technique. By combination of targeted MS/MS, the approach enables sensitive and accurate characterization of the protein MetR sites in a large-scale manner. The project aims to: (1) design the stable isotope labeled amino acids for encoding of proteins in cell cultures to obtain site-specific labeling of MetRs; (2) develop an algorithm for screening of NeuCode signatures in mass spectra, and establish an efficient analytical pipeline for identification and quantification of protein MetR; (3) apply the coNeuCode technique for screening of substrates of protein arginine methyltransferases in cancer cells, and obtain the site map and regulatory network; (4) and, design and patent coNeuCode kits.