title: Improvement of hydrophobic integral membrane protein identification by mild performic acid oxidation-assisted digestion.
abstract: Integral membrane proteins (IMPs) are critical for the maintenance of biological systems and represent important targets for the treatment of disease. The hydrophobicity and low abundance of IMPs make them difficult to analyze. In proteomic analyses, hydrophobic peptides including transmembrane domains are often underrepresented, and this reduces the sequence coverage and reliability of the identified IMPs. Here we report a new strategy, mild performic acid oxidation treatment (mPAOT), for improvement of IMP identification. In the mPAOT strategy, the hydrophobicity of IMPs is significantly decreased by oxidizing their methionine and cysteine residues with performic acid, thereby improving the solubility and enzymolysis of these proteins. The application of the mPAOT strategy to the analysis of IMPs from human nasopharyngeal carcinoma CNE1 cell line demonstrated that many IMPs, including those with high hydrophobicity, could be reliably identified.
authors: Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, People's Republic of China.
authors: Rui
authors: R
authors: Cao
authors: Yisong
authors: Y
authors: Liu
authors: Ping
authors: P
authors: Chen
authors: Rong
authors: R
authors: Lv
authors: Qin
authors: Q
authors: Song
authors: Tingting
authors: T
authors: Sheng
authors: Quanyuan
authors: Q
authors: He
authors: Yin
authors: Y
authors: Wang
authors: Xianchun
authors: X
authors: Wang
authors: Songping
authors: S
authors: Liang
mesh_terms: D045744:Cell Line, Tumor; D003545:Cysteine / Q000737:chemistry; D005561:Formates / Q000737:chemistry*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D013058:Mass Spectrometry / Q000379:methods*; D008565:Membrane Proteins / Q000032:analysis* / Q000737:chemistry; D008715:Methionine / Q000737:chemistry; D010084:Oxidation-Reduction; D010455:Peptides / Q000737:chemistry
chemical_list: D005561:Formates; D008565:Membrane Proteins; D010455:Peptides; C008817:peroxyformic acid; D008715:Methionine; D003545:Cysteine