**Author details**

**Acknowledgements**

120 Electrophoresis - Life Sciences Practical Applications

acknowledged.

organizations.

**Conflict of interest**

**Acronyms and abbreviations**

CNS central nervous system

ESI electrospray ionization

MS/MS tandem mass spectrometry NTAC nitrotyrosine affinity column

PAGE polyacrylamide gel electrophoresis

PTM posttranslational modification

Q-IT quadrupole ion trap

S/N signal-to-noise ratio

RNS reactive nitrogen species SDS sodium dodecyl sulfate

TEMED tetramethylethylenediamine

1DGE one-dimensional gel electrophoresis 2DGE two-dimensional gel electrophoresis

FDR false discovery rates IEF isoelectic focusing

ELISA enzyme-linked immunosorbent assay

MALDI matrix-assisted laser desorption ionization

The authors acknowledge the financial supports from the National Natural Science Foundation of China (Grant No. 81572278 and 81272798 to X.Z.), China "863" Plan Project (Grant No. 2014AA020610-1 to X.Z.), the Hunan Provincial Natural Science Foundation of China (Grant No. 14JJ7008 to X.Z.), and the Xiangya Hospital Funds for Talent Introduction (to X.Z.). The scientific contributions of Dr. Dominic M. Desiderio and Fang Peng are also

We declare that we have no financial and personal relationships with other people or

Xianquan Zhan\* and Na Li

\*Address all correspondence to: yjzhan2011@gmail.com

Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha, China
