Dai Jingquan, Wang Jinglan, Zhang Yangjun, Lu Zhuang, Yang Bing, Li Xiaohai, Cai Yun, Qian Xiaohong
Beijing Institute of Radiation Medicine, China.
Anal Chem. 2005 Dec 1;77(23):7594-604. doi: 10.1021/ac0506276.
The extreme complexity of sample and uninformative fragmentation of peptides in MS/MS experiments are two of several real challenges faced by proteomics. In this work, a strategy aimed at tackling these two problems is presented. Briefly, proteins were first oxidized by performic acid to cleave the disulfide bonds and simultaneously convert cysteine residue into its sulfonic form. Then the resultant sulfonic peptides were enriched by SCX chromatography, exploiting the negative solution charge of sulfonic group. The sulfonic peptide could be easily detected by MALDI-MS in negative mode and showed both enhanced fragmentation efficiency and a simplified spectrum in MALDI-MS/MS experiment in positive mode. The strength of the strategy was demonstrated by applying it to bovine serum albumin. Potential use of the strategy in proteomics was also discussed.
在串联质谱（MS/MS）实验中，样品的极端复杂性以及肽段信息不足的碎片化是蛋白质组学面临的几个实际挑战中的两个。在这项工作中，提出了一种旨在解决这两个问题的策略。简而言之，首先用过甲酸氧化蛋白质以裂解二硫键，并同时将半胱氨酸残基转化为磺酸形式。然后，利用磺酸基团的负电荷，通过强阳离子交换（SCX）色谱法富集所得的磺酸肽。磺酸肽在负离子模式下可通过基质辅助激光解吸电离质谱（MALDI-MS）轻松检测到，并且在正离子模式的MALDI-MS/MS实验中显示出增强的碎片化效率和简化的谱图。通过将该策略应用于牛血清白蛋白证明了其优势。还讨论了该策略在蛋白质组学中的潜在用途。
