Abstract
AbstractRecently, technologies with using stable isotope coding had been developed for more accurate and sensitive analysis of protein determination in proteomics. To date, isotopic reagents have targeted with the specific feature in the peptides, such as the sulfhydryl group of cysteine. Solid-phase ICAT isotopic coding method, peptide from low aboundance protein could be detected with good sensitivity and without complications from isotope effect. In this thesis, we describe an attempt to develop a similar lysine tagging reagent for solid-support-based quantitative proteomics applications. Peters et al. have reported that 2-methoxy-4,5-dihydro-1H-imidazole is an excellent electrophile that reacts with the lysine residue from the corresponding high mass sensitive guanidine ions. Towards this end, we have synthesized methyl 4,5-dihydro-2-methoxy-1H-imidazole-5-carboxylate and successfully examined its applicability for tagging to the lysine residue. This novel lysine tagging reagent should pave the way toward differential quantitation studies proteomics. Finally, we have extended the work to other functional group, such as the –COOH (carboxyl group) and the –OH (hydroxyl group) so that the reagent could be used as an amino linker or ester linker toward the photo-cleavable ligand and solid support.