Stable Isotope Coded Labeling Reagents For Quantitative Proteomics

One of the most important subjects in contemporary proteomics is the relative and absolute quantification of gene expression at the protein level. The application of stable-isotope coded tagging in conjunction with high performance bioanalytical methods such as liquid chromatography and mass spectrometry for the separation and identification of proteins and peptides has proven successful to reveal global changes in protein expression in both comparative and absolute manners. The rapid progress in the field is evidenced by the introduction of quite a few stable isotope labeled novel reagents for protein and peptide tagging with particular structural characteristics. In this review we focus on the chemical design, structure and synthesis of the most important of such tagging reagents, also addressing their advantages and limitations in quantitative proteomics.