Abstract

Stable isotope labeling coupled with multidimensional liquid chromatography/tandem mass spectrometry is an advanced platform for global proteome-wide quantification. Compared to conventional methods, such as two dimensional polyacrylamide gel or electroblot based quantification methods, stable isotope labeling holds greater promise for accurate and large-scale quantitative analyses. Various labeling strategies have been developed to analyze protein expression, posttranslational modification, and protein/protein interactions, as well as for absolute quantification. There are advantages and disadvantages inherent with each method, but their applicability is dependent on many factors. In addition to the choice of which labeling chemistry to be used, there are several bottleneck issues associated with this approach that are of critical importance. These include finding effective multidimensional separation steps to resolve low abundant proteins present in relatively complicated mixtures, validating the methods, and interpreting the large amount of statistical data generated. This review covers the current progress in solving these concerns and summarizes the various labeling strategies and applications. We believe that a judicious integration of each component of the technique is crucial for the success of such a global systems approach. Based on the current progress, it is clear that the stable isotope labeling/mass spectrometry technique will find tremendous use in many fields, such as drug discovery, clinical diagnostics, disease prevention, basic biological research, and biotechnology.

Keywords: Quantitative proteomics, stable isotope labeling, multidimensional liquid chromatography, mass spectrometry