Integrated platform with combination of on-line protein digestion, isotope dimethyl labeling and multidimensional peptide separation for high-throughput proteome quantification.

In recent years, various enzymatic microreactors and on-line enzyme digestion strategies have been widely applied in high throughput proteome analysis. However, the incomplete and irreproducible digestion would introduce some unexpected variations in comparative proteome quantification when the samples are digested and then chemically isotope labeled in different aliquots. To address these problems, we developed an integrated platform for high throughput proteome quantification with combination of on-line low miss-cleavage protein digestion by an ultra-performance immobilized enzymatic reactor, on-line dimethyl labeling onto a C18 precolumn, peptide separation by two-dimensional nano liquid chromatography and MS detection. Compared to traditional off-line method, such a platform exhibits obvious advantages such as high sensitivity, throughput, accuracy, precision and ease of automation. All these results demonstrated that such a platform might become a promising technique for the quantitative proteome analysis.