Method for quantitative proteomics research by using metal element chelated tags coupled with mass spectrometry

Area of Science:

• Proteomics
• Analytical Chemistry
• Biochemistry

Background:

• Quantitative proteomics commonly employs mass spectrometry with stable isotope internal standards.
• Existing stable isotope reagents face limitations due to high cost and complex synthesis.
• There is a need for more accessible and economical quantitative proteomics methods.

Purpose of the Study:

• To develop a novel, economical method for quantitative proteomics using metal element chelated tags (MECT).
• To evaluate the efficacy of MECT coupled with mass spectrometry for protein quantification and identification.

Main Methods:

• Diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA) was covalently coupled to peptides.
• DTPA ligands were chelated with rare earth metals Yttrium (Y) and Terbium (Tb).
• Tagged peptides were analyzed using Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry (LC-ESI-MS/MS) for quantification.

Main Results:

• Metal chelate-tagged peptides demonstrated successful coelution during reversed-phase LC analysis.
• Accurate relative quantification of proteins was achieved using the MECT method.
• DTPA modification enhanced MS/MS fragmentation, yielding predominantly y-series ions, improving protein identification confidence.

Conclusions:

• The MECT strategy provides a simple, rapid, and economical alternative for quantitative proteomics.
• This method overcomes the cost and synthetic challenges associated with traditional stable isotope reagents.
• MECT enhances protein identification accuracy and efficiency in mass spectrometry-based proteomics.