MULTI-PROTEIN QUANTITATION METHOD BASED ON EQUIPONDEROUS DIMETHYLATION MARKING

摘要

A multi-protein quantitation method based on equiponderous dimethylation marking. By means of a property that a dimethylation reaction has different rates on an amino group at a peptide N-terminal and an amino group on a lysine side chain at a peptide C-terminal, dimethylation marking of the peptide N-terminal and the C-terminal in an acid condition and an alkaline condition is implemented one after another; and multiple marking of a peptide sample is implemented by means of organic combination of a variety isotope forms of a dimethylation marking reagent. First-order spectrum mass-to-charge ratios of the peptide after multiple marking are completely the same, the mass-to-charge ratios of second-order spectrum fragment ions are different, and multiple quantitative analysis is carried out by extracting the corresponding second-order spectrum fragment ions. The method has the advantages: the quantitative accuracy is high, the precision is good, the dynamic range is wide, and simultaneous quantitative analysis of six protein samples can be simultaneously implemented, thereby greatly improving the flux of the quantitative analysis of protein, and saving analysis time.