A rapid and efficient method for N-termini analysis in short-lived proteins

Area of Science:

• Proteomics
• Biochemistry
• Analytical Chemistry

Background:

• Identifying protein N-termini is crucial for understanding protein function and regulation.
• Traditional methods for N-termini isolation are often time-consuming and inefficient, especially for unstable proteins.

Purpose of the Study:

• To develop a rapid and efficient method for global N-termini isolation.
• To enable the identification of unstable N-termini in short-lived proteins.

Main Methods:

• Utilized laser-assisted proteolysis to accelerate protein digestion by trypsin.
• Employed Fe3O4 microspheres for efficient capture and isolation of N-terminal peptides.
• Applied Traut's reagent for derivatization of non-N-terminal peptides, facilitating their separation.

Main Results:

• Achieved isolation of protein N-termini within 4 hours, a significant reduction from overnight digestion.
• Successfully identified N-terminal peptides from human serum albumin as a model.
• Identified 2011 N-terminal peptides from 936 proteins in a mouse liver proteome sample using LC-MS/MS.

Conclusions:

• The developed method is facile and efficient for N-termini enrichment.
• This technique is particularly beneficial for targeted protein N-termini analysis, especially for proteins with short half-lives.