A Tris (2-Carboxyethyl) Phosphine (TCEP) Related Cleavage on Cysteine-Containing Proteins

作者：Liu Peiran; O'Mara Brian W; Warrack Bethanne M; Wu Wei; Huang Yunping; Zhang Yihong; Zhao Rulin; Lin Mei; Ackerman Michael S; Hocknell Peter K; Chen Guodong; Tao Li; Rieble Siegfried; Wang Jack; Wang Iverson David B; Tymiak Adrienne A; Grace Michael J; Russell Reb J^*

来源：Journal of the American Society for Mass Spectrometry, 2010, 21(5): 837-844.

DOI：10.1016/j.jasms.2010.01.016

Introduced in the late 1980s as a reducing reagent, Tris (2-carboxyethyl) phosphine (TCEP) has now become one of the most widely used protein reductants. To date, only a few studies on its side reactions have been published. We report the observation of a side reaction that cleaves protein backbones under mild conditions by fracturing the cysteine residues, thus generating heterogeneous peptides containing different moieties from the fractured cysteine. The peptide products were analyzed by high performance liquid chromatography and tandem mass spectrometry (LC/MS/MS). Peptides with a primary amine and a carboxylic acid as termini were observed, and others were found to contain amidated or formamidated carboxy termini, or formylated or glyoxylic amino termini. Formamidation of the carboxy terminus and the formation of glyoxylic amino terminus were unexpected reactions since both involve breaking of carbon-carbon bonds in cysteine.

• 出版日期2010-5