Mass- and property-tuned variable mass labeling reagents and analytical methods for simultaneous peptide sequencing and multiplexed protein quantification using thereof

A variable mass labeling reagent represented by the following Formula 1:

• wherein RS and RB are each straight or branched chain C1-C18 alkyl;
• at least one of RS and RB contains one or more deuterium atoms;
• RT is a side chain of an amino acid selected from the group consisting of serine (Ser), histidine (His), glutamine (Gln), phenylalanine (Phe), arginine (Arg) and tyrosine (Tyr), or a straight or branched C2-C18 alkyl;
• and Linker is selected from the group consisting of hydroxy group, N-hydroxysuccinimidyl group, N-hydroxysulfosuccinimidyl group, benzotriazol-1-yloxyl group, pentahalobenzyl group and 4-nitrophenyl group, with the proviso that RS and RB are composed of alkyl having the same number of carbon atoms, but different numbers of deuterium atoms.