摘要
The post translational modifications of histone variants are playing an important role in the structure of chromatin, the regulation of gene activities and the diagnosis of diseases, and conducting in-depth researches and discovering new sites depend on new and rational analytical methods to some extent. In this work, the combinatorial method of high resolution LTQ-Orbitrap mass spectrometry and multiple enzymes was employed to identify the post translational modifications （PTMs） of histone H4 of human liver cells. The novel methylation site, argnine 67 （R 67）, was observed besides some sites reported previously such as lysine 31 （K 31）, lysine 44 （K 44）, argnine 55 （R 55） and lysine 59 （K 59） in the global domain. Meanwhile, various combinations of acetylation of lysine 5 （K 5）, lysine 8 （K 8）, lysine 12 （K 12）, lysine 16 （K 16） and methylation of lysine 20 （K 20） in the NH2-terminal tails were also identified after the LC-MS/MS analysis of trypsin, Arg-C, Glu-C and chymotrypsin digests.
The post translational modifications of histone variants are playing an important role in the structure of chromatin, the regulation of gene activities and the diagnosis of diseases, and conducting in-depth researches and discovering new sites depend on new and rational analytical methods to some extent. In this work, the combinatorial method of high resolution LTQ-Orbitrap mass spectrometry and multiple enzymes was employed to identify the post translational modifications （PTMs） of histone H4 of human liver cells. The novel methylation site, argnine 67 （R 67）, was observed besides some sites reported previously such as lysine 31 （K 31）, lysine 44 （K 44）, argnine 55 （R 55） and lysine 59 （K 59） in the global domain. Meanwhile, various combinations of acetylation of lysine 5 （K 5）, lysine 8 （K 8）, lysine 12 （K 12）, lysine 16 （K 16） and methylation of lysine 20 （K 20） in the NH2-terminal tails were also identified after the LC-MS/MS analysis of trypsin, Arg-C, Glu-C and chymotrypsin digests.
基金
Project supported by the National Science and Technology Key Project （No. 2009CB825607）, National Natural Science Foundation of China （Nos. 20875016, 31070732）, Ministry of Education of China （20080246011）, Shanghai Projects （Shuguang Eastern Scholar and B 109）.
