ARS | Publication request: Protein N- and C-Termini Identification Using Mass Spectrometry and Isotopic Labeling

Submitted to: Journal of Rapid Communications in Mass Spectroscopy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 20, 2009
Publication Date: June 29, 2009
Citation: Xiang, B., Yang, X., Thannhauser, T.W. 2009. Protein N- and C-Termini Identification Using Mass Spectrometry and Isotopic Labeling. Journal of Rapid Communications in Mass Spectroscopy. 23:2102-2106.

Interpretive Summary: The determination of a protein's amino- and carboxyl-termini is critical because the actual protein sequence may be different from that translated from its DNA sequence due to the truncation as post-translational modification or artifact of the protein purification process. We have developed a novel method involving mass spectrometry and stable isotope coding that allows one to determine which of the many peptides produced through enzymatic digestion represents the amino or carboxyl terminal peptides easily, through the recognition of the distinct pattern generated by each. The method is applicable to proteins isolated both chromatographically and electrophoretically and it is not limited by the size of the proteins or terminal blocking.

Technical Abstract: A new method for protein N- and C-terminal analysis using mass spectrometry is introduced. A novel stable isotopic labeling scheme has been developed to identify terminal peptides generated from an enzyme digestion for the determination of both N- and C-termini of the protein. This method works directly for proteins isolated in an electrophoresis gel and is not limited by protein size and terminal blocking.